原文地址为：
Android-Universal-Image-Loader三大组件DisplayImageOptions、ImageLoader、ImageLoaderConfiguration详解
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转载请注明本文地址： Android-Universal-Image-Loader三大组件DisplayImageOptions、ImageLoader、ImageLoaderConfiguration详解
一、介绍
Android-Universal-Image-Loader是一个开源的UI组件程序，该项目的目的是提供一个可重复使用的仪器为异步图像加载，缓存和显示。所以，如果你的程序里需要这个功能的话，那么不妨试试它。因为已经封装好了一些类和方法。我们 可以直接拿来用了。而不用重复去写了。其实，写一个这方面的程序还是比较麻烦的，要考虑多线程缓存，内存溢出等很多方面。
二、具体使用
一个好的类库的重要特征就是可配置性强。我们先简单使用Android-Universal-Image-Loader，一般情况下使用默认配置就可以了。
下面的实例利用Android-Universal-Image-Loader将网络图片加载到图片墙中。
1 public class BaseActivity extends Activity {
2 ImageLoader imageLoader;
3 @Override
4 protected void onCreate(Bundle savedInstanceState) {
5 // Create global configuration and initialize ImageLoader with this configuration
6 ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(getApplicationContext())
7 .build();
8 ImageLoader.getInstance().init(config);
9 super.onCreate(savedInstanceState);
10 }
11 }
1 public class MainActivity extends BaseActivity {
2
3 @Override
4 protected void onCreate(Bundle savedInstanceState) {
5 super.onCreate(savedInstanceState);
6 setContentView(R.layout.activity_main);
7
8 ImageLoader imageLoader = ImageLoader.getInstance();
9
10 GridView gridView = (GridView) this.findViewById(R.id.grdvImageWall);
11 gridView.setAdapter(new PhotoWallAdapter(Constants.IMAGES));
12 }
13
14 static class ViewHolder {
15 ImageView imageView;
16 ProgressBar progressBar;
17 }
18
19 public class PhotoWallAdapter extends BaseAdapter {
20 String[] imageUrls;
21 ImageLoader imageLoad;
22 DisplayImageOptions options;
23 LinearLayout gridViewItem;
24
25 public PhotoWallAdapter(String[] imageUrls) {
26 assert imageUrls != null;
27 this.imageUrls = imageUrls;
28
29 options = new DisplayImageOptions.Builder()
30 .showImageOnLoading(R.drawable.ic_stub) // resource or
31 // drawable
32 .showImageForEmptyUri(R.drawable.ic_empty) // resource or
33 // drawable
34 .showImageOnFail(R.drawable.ic_error) // resource or
35 // drawable
36 .resetViewBeforeLoading(false) // default
37 .delayBeforeLoading(1000).cacheInMemory(false) // default
38 .cacheOnDisk(false) // default
39 .considerExifParams(false) // default
40 .imageScaleType(ImageScaleType.IN_SAMPLE_POWER_OF_2) // default
41 .bitmapConfig(Bitmap.Config.ARGB_8888) // default
42 .displayer(new SimpleBitmapDisplayer()) // default
43 .handler(new Handler()) // default
44 .build();
45 this.imageLoad = ImageLoader.getInstance();
46
47 }
48
49 @Override
50 public int getCount() {
51 return this.imageUrls.length;
52 }
53
54 @Override
55 public Object getItem(int position) {
56 if (position <= 0 || position >= this.imageUrls.length) {
57 throw new IllegalArgumentException(
58 "position<=0||position>=this.imageUrls.length");
59 }
60 return this.imageUrls[position];
61 }
62
63 @Override
64 public long getItemId(int position) {
65 return position;
66 }
67
68 @Override
69 public View getView(int position, View convertView, ViewGroup parent) {
70 // 判断这个image是否已经在缓存当中，如果没有就下载
71 final ViewHolder holder;
72 if (convertView == null) {
73 holder = new ViewHolder();
74 gridViewItem = (LinearLayout) getLayoutInflater().inflate(
75 R.layout.image_wall_item, null);
76 holder.imageView = (ImageView) gridViewItem
77 .findViewById(R.id.item_image);
78 holder.progressBar = (ProgressBar) gridViewItem
79 .findViewById(R.id.item_process);
80 gridViewItem.setTag(holder);
81 convertView = gridViewItem;
82 } else {
83 holder = (ViewHolder) gridViewItem.getTag();
84 }
85 this.imageLoad.displayImage(this.imageUrls[position],
86 holder.imageView, options,
87 new SimpleImageLoadingListener() {
88
89 @Override
90 public void onLoadingStarted(String imageUri, View view) {
91 holder.progressBar.setProgress(0);
92 holder.progressBar.setVisibility(View.VISIBLE);
93 }
94
95 @Override
96 public void onLoadingFailed(String imageUri, View view,
97 FailReason failReason) {
98 holder.progressBar.setVisibility(View.GONE);
99 }
100
101 @Override
102 public void onLoadingComplete(String imageUri,
103 View view, Bitmap loadedImage) {
104 holder.progressBar.setVisibility(View.GONE);
105 }
106
107 }, new ImageLoadingProgressListener() {
108
109 @Override
110 public void onProgressUpdate(String imageUri,
111 View view, int current, int total) {
112 holder.progressBar.setProgress(Math.round(100.0f
113 * current / total));
114 }
115 }); // 通过URL判断图片是否已经下载
116 return convertView;
117 }
118
119 }
120 }
里面主要的对象都用 突出显示了。
三者的关系
ImageLoaderConfiguration是针对图片缓存的全局配置，主要有线程类、缓存大小、磁盘大小、图片下载与解析、日志方面的配置。
ImageLoader是具体下载图片，缓存图片，显示图片的具体执行类，它有两个具体的方法displayImage(...)、loadImage(...)，但是其实最终他们的实现都是displayImage(...)。
DisplayImageOptions用于指导每一个Imageloader根据网络图片的状态（空白、下载错误、正在下载）显示对应的图片，是否将缓存加载到磁盘上，下载完后对图片进行怎么样的处理。
从三者的协作关系上看，他们有点像厨房规定、厨师、客户个人口味之间的关系。ImageLoaderConfiguration就像是厨房里面的规定，每一个厨师要怎么着装，要怎么保持厨房的干净，这是针对每一个厨师都适用的规定，而且不允许个性化改变。ImageLoader就像是具体做菜的厨师，负责具体菜谱的制作。DisplayImageOptions就像每个客户的偏好，根据客户是重口味还是清淡，每一个imageLoader根据DisplayImageOptions的要求具体执行。
ImageLoaderConfiguration
在上面的示例代码中，我们使用ImageLoaderConfiguration的默认配置，下面给出ImageLoaderConfiguration比较详尽的配置，从下面的配置中，可以看出ImageLoaderConfiguration的配置主要是全局性的配置，主要有线程类、缓存大小、磁盘大小、图片下载与解析、日志方面的配置。
ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(context)
.memoryCacheExtraOptions(480, 800) // default = device screen dimensions
.diskCacheExtraOptions(480, 800, null)
.taskExecutor(...)
.taskExecutorForCachedImages(...)
.threadPoolSize(3) // default
.threadPriority(Thread.NORM_PRIORITY - 1) // default
.tasksProcessingOrder(QueueProcessingType.FIFO) // default
.denyCacheImageMultipleSizesInMemory()
.memoryCache(new LruMemoryCache(2 * 1024 * 1024))
.memoryCacheSize(2 * 1024 * 1024)
.memoryCacheSizePercentage(13) // default
.diskCache(new UnlimitedDiscCache(cacheDir)) // default
.diskCacheSize(50 * 1024 * 1024)
.diskCacheFileCount(100)
.diskCacheFileNameGenerator(new HashCodeFileNameGenerator()) // default
.imageDownloader(new BaseImageDownloader(context)) // default
.imageDecoder(new BaseImageDecoder()) // default
.defaultDisplayImageOptions(DisplayImageOptions.createSimple()) // default
.writeDebugLogs()
.build();
ImageLoaderConfiguration的主要职责就是记录相关的配置，它的内部其实就是一些字段的集合（如下面的源代码）。它有一个builder的内部类，这个类中的字段跟ImageLoaderConfiguration中的字段完全一致，它有一些默认值，通过修改builder可以配置ImageLoaderConfiguration。
1 /*******************************************************************************
2 * Copyright 2011-2013 Sergey Tarasevich
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 *******************************************************************************/
16 package com.nostra13.universalimageloader.core;
17
18 import android.content.Context;
19 import android.content.res.Resources;
20 import android.util.DisplayMetrics;
21 import com.nostra13.universalimageloader.cache.disc.DiskCache;
22 import com.nostra13.universalimageloader.cache.disc.naming.FileNameGenerator;
23 import com.nostra13.universalimageloader.cache.memory.MemoryCache;
24 import com.nostra13.universalimageloader.cache.memory.impl.FuzzyKeyMemoryCache;
25 import com.nostra13.universalimageloader.core.assist.FlushedInputStream;
26 import com.nostra13.universalimageloader.core.assist.ImageSize;
27 import com.nostra13.universalimageloader.core.assist.QueueProcessingType;
28 import com.nostra13.universalimageloader.core.decode.ImageDecoder;
29 import com.nostra13.universalimageloader.core.download.ImageDownloader;
30 import com.nostra13.universalimageloader.core.process.BitmapProcessor;
31 import com.nostra13.universalimageloader.utils.L;
32 import com.nostra13.universalimageloader.utils.MemoryCacheUtils;
33
34 import java.io.IOException;
35 import java.io.InputStream;
36 import java.util.concurrent.Executor;
37
38 /**
39 * Presents configuration for {@link ImageLoader}
40 *
41 * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
42 * @see ImageLoader
43 * @see MemoryCache
44 * @see DiskCache
45 * @see DisplayImageOptions
46 * @see ImageDownloader
47 * @see FileNameGenerator
48 * @since 1.0.0
49 */
50 public final class ImageLoaderConfiguration {
51
52 final Resources resources;
53
54 final int maxImageWidthForMemoryCache;
55 final int maxImageHeightForMemoryCache;
56 final int maxImageWidthForDiskCache;
57 final int maxImageHeightForDiskCache;
58 final BitmapProcessor processorForDiskCache;
59
60 final Executor taskExecutor;
61 final Executor taskExecutorForCachedImages;
62 final boolean customExecutor;
63 final boolean customExecutorForCachedImages;
64
65 final int threadPoolSize;
66 final int threadPriority;
67 final QueueProcessingType tasksProcessingType;
68
69 final MemoryCache memoryCache;
70 final DiskCache diskCache;
71 final ImageDownloader downloader;
72 final ImageDecoder decoder;
73 final DisplayImageOptions defaultDisplayImageOptions;
74
75 final ImageDownloader networkDeniedDownloader;
76 final ImageDownloader slowNetworkDownloader;
77
78 private ImageLoaderConfiguration(final Builder builder) {
79 resources = builder.context.getResources();
80 maxImageWidthForMemoryCache = builder.maxImageWidthForMemoryCache;
81 maxImageHeightForMemoryCache = builder.maxImageHeightForMemoryCache;
82 maxImageWidthForDiskCache = builder.maxImageWidthForDiskCache;
83 maxImageHeightForDiskCache = builder.maxImageHeightForDiskCache;
84 processorForDiskCache = builder.processorForDiskCache;
85 taskExecutor = builder.taskExecutor;
86 taskExecutorForCachedImages = builder.taskExecutorForCachedImages;
87 threadPoolSize = builder.threadPoolSize;
88 threadPriority = builder.threadPriority;
89 tasksProcessingType = builder.tasksProcessingType;
90 diskCache = builder.diskCache;
91 memoryCache = builder.memoryCache;
92 defaultDisplayImageOptions = builder.defaultDisplayImageOptions;
93 downloader = builder.downloader;
94 decoder = builder.decoder;
95
96 customExecutor = builder.customExecutor;
97 customExecutorForCachedImages = builder.customExecutorForCachedImages;
98
99 networkDeniedDownloader = new NetworkDeniedImageDownloader(downloader);
100 slowNetworkDownloader = new SlowNetworkImageDownloader(downloader);
101
102 L.writeDebugLogs(builder.writeLogs);
103 }
104
105 /**
106 * Creates default configuration for {@link ImageLoader} <br />
107 * <b>Default values:</b>
108 * <ul>
109 * <li>maxImageWidthForMemoryCache = device's screen width</li>
110 * <li>maxImageHeightForMemoryCache = device's screen height</li>
111 * <li>maxImageWidthForDikcCache = unlimited</li>
112 * <li>maxImageHeightForDiskCache = unlimited</li>
113 * <li>threadPoolSize = {@link Builder#DEFAULT_THREAD_POOL_SIZE this}</li>
114 * <li>threadPriority = {@link Builder#DEFAULT_THREAD_PRIORITY this}</li>
115 * <li>allow to cache different sizes of image in memory</li>
116 * <li>memoryCache = {@link DefaultConfigurationFactory#createMemoryCache(int)}</li>
117 * <li>diskCache = {@link com.nostra13.universalimageloader.cache.disc.impl.UnlimitedDiscCache}</li>
118 * <li>imageDownloader = {@link DefaultConfigurationFactory#createImageDownloader(Context)}</li>
119 * <li>imageDecoder = {@link DefaultConfigurationFactory#createImageDecoder(boolean)}</li>
120 * <li>diskCacheFileNameGenerator = {@link DefaultConfigurationFactory#createFileNameGenerator()}</li>
121 * <li>defaultDisplayImageOptions = {@link DisplayImageOptions#createSimple() Simple options}</li>
122 * <li>tasksProcessingOrder = {@link QueueProcessingType#FIFO}</li>
123 * <li>detailed logging disabled</li>
124 * </ul>
125 */
126 public static ImageLoaderConfiguration createDefault(Context context) {
127 return new Builder(context).build();
128 }
129
130 ImageSize getMaxImageSize() {
131 DisplayMetrics displayMetrics = resources.getDisplayMetrics();
132
133 int width = maxImageWidthForMemoryCache;
134 if (width <= 0) {
135 width = displayMetrics.widthPixels;
136 }
137 int height = maxImageHeightForMemoryCache;
138 if (height <= 0) {
139 height = displayMetrics.heightPixels;
140 }
141 return new ImageSize(width, height);
142 }
143
144 /**
145 * Builder for {@link ImageLoaderConfiguration}
146 *
147 * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
148 */
149 public static class Builder {
150
151 private static final String WARNING_OVERLAP_DISK_CACHE_PARAMS = "diskCache(), diskCacheSize() and diskCacheFileCount calls overlap each other";
152 private static final String WARNING_OVERLAP_DISK_CACHE_NAME_GENERATOR = "diskCache() and diskCacheFileNameGenerator() calls overlap each other";
153 private static final String WARNING_OVERLAP_MEMORY_CACHE = "memoryCache() and memoryCacheSize() calls overlap each other";
154 private static final String WARNING_OVERLAP_EXECUTOR = "threadPoolSize(), threadPriority() and tasksProcessingOrder() calls "
155 + "can overlap taskExecutor() and taskExecutorForCachedImages() calls.";
156
157 /** {@value} */
158 public static final int DEFAULT_THREAD_POOL_SIZE = 3;
159 /** {@value} */
160 public static final int DEFAULT_THREAD_PRIORITY = Thread.NORM_PRIORITY - 1;
161 /** {@value} */
162 public static final QueueProcessingType DEFAULT_TASK_PROCESSING_TYPE = QueueProcessingType.FIFO;
163
164 private Context context;
165
166 private int maxImageWidthForMemoryCache = 0;
167 private int maxImageHeightForMemoryCache = 0;
168 private int maxImageWidthForDiskCache = 0;
169 private int maxImageHeightForDiskCache = 0;
170 private BitmapProcessor processorForDiskCache = null;
171
172 private Executor taskExecutor = null;
173 private Executor taskExecutorForCachedImages = null;
174 private boolean customExecutor = false;
175 private boolean customExecutorForCachedImages = false;
176
177 private int threadPoolSize = DEFAULT_THREAD_POOL_SIZE;
178 private int threadPriority = DEFAULT_THREAD_PRIORITY;
179 private boolean denyCacheImageMultipleSizesInMemory = false;
180 private QueueProcessingType tasksProcessingType = DEFAULT_TASK_PROCESSING_TYPE;
181
182 private int memoryCacheSize = 0;
183 private long diskCacheSize = 0;
184 private int diskCacheFileCount = 0;
185
186 private MemoryCache memoryCache = null;
187 private DiskCache diskCache = null;
188 private FileNameGenerator diskCacheFileNameGenerator = null;
189 private ImageDownloader downloader = null;
190 private ImageDecoder decoder;
191 private DisplayImageOptions defaultDisplayImageOptions = null;
192
193 private boolean writeLogs = false;
194
195 public Builder(Context context) {
196 this.context = context.getApplicationContext();
197 }
198
199 /**
200 * Sets options for memory cache
201 *
202 * @param maxImageWidthForMemoryCache Maximum image width which will be used for memory saving during decoding
203 * an image to {@link android.graphics.Bitmap Bitmap}. <b>Default value - device's screen width</b>
204 * @param maxImageHeightForMemoryCache Maximum image height which will be used for memory saving during decoding
205 * an image to {@link android.graphics.Bitmap Bitmap}. <b>Default value</b> - device's screen height
206 */
207 public Builder memoryCacheExtraOptions(int maxImageWidthForMemoryCache, int maxImageHeightForMemoryCache) {
208 this.maxImageWidthForMemoryCache = maxImageWidthForMemoryCache;
209 this.maxImageHeightForMemoryCache = maxImageHeightForMemoryCache;
210 return this;
211 }
212
213 /**
214 * @deprecated Use
215 * {@link #diskCacheExtraOptions(int, int, com.nostra13.universalimageloader.core.process.BitmapProcessor)}
216 * instead
217 */
218 @Deprecated
219 public Builder discCacheExtraOptions(int maxImageWidthForDiskCache, int maxImageHeightForDiskCache,
220 BitmapProcessor processorForDiskCache) {
221 return diskCacheExtraOptions(maxImageWidthForDiskCache, maxImageHeightForDiskCache, processorForDiskCache);
222 }
223
224 /**
225 * Sets options for resizing/compressing of downloaded images before saving to disk cache.<br />
226 * <b>NOTE: Use this option only when you have appropriate needs. It can make ImageLoader slower.</b>
227 *
228 * @param maxImageWidthForDiskCache Maximum width of downloaded images for saving at disk cache
229 * @param maxImageHeightForDiskCache Maximum height of downloaded images for saving at disk cache
230 * @param processorForDiskCache null-ok; {@linkplain BitmapProcessor Bitmap processor} which process images before saving them in disc cache
231 */
232 public Builder diskCacheExtraOptions(int maxImageWidthForDiskCache, int maxImageHeightForDiskCache,
233 BitmapProcessor processorForDiskCache) {
234 this.maxImageWidthForDiskCache = maxImageWidthForDiskCache;
235 this.maxImageHeightForDiskCache = maxImageHeightForDiskCache;
236 this.processorForDiskCache = processorForDiskCache;
237 return this;
238 }
239
240 /**
241 * Sets custom {@linkplain Executor executor} for tasks of loading and displaying images.<br />
242 * <br />
243 * <b>NOTE:</b> If you set custom executor then following configuration options will not be considered for this
244 * executor:
245 * <ul>
246 * <li>{@link #threadPoolSize(int)}</li>
247 * <li>{@link #threadPriority(int)}</li>
248 * <li>{@link #tasksProcessingOrder(QueueProcessingType)}</li>
249 * </ul>
250 *
251 * @see #taskExecutorForCachedImages(Executor)
252 */
253 public Builder taskExecutor(Executor executor) {
254 if (threadPoolSize != DEFAULT_THREAD_POOL_SIZE || threadPriority != DEFAULT_THREAD_PRIORITY || tasksProcessingType != DEFAULT_TASK_PROCESSING_TYPE) {
255 L.w(WARNING_OVERLAP_EXECUTOR);
256 }
257
258 this.taskExecutor = executor;
259 return this;
260 }
261
262 /**
263 * Sets custom {@linkplain Executor executor} for tasks of displaying <b>cached on disk</b> images (these tasks
264 * are executed quickly so UIL prefer to use separate executor for them).<br />
265 * <br />
266 * If you set the same executor for {@linkplain #taskExecutor(Executor) general tasks} and
267 * tasks about cached images (this method) then these tasks will be in the
268 * same thread pool. So short-lived tasks can wait a long time for their turn.<br />
269 * <br />
270 * <b>NOTE:</b> If you set custom executor then following configuration options will not be considered for this
271 * executor:
272 * <ul>
273 * <li>{@link #threadPoolSize(int)}</li>
274 * <li>{@link #threadPriority(int)}</li>
275 * <li>{@link #tasksProcessingOrder(QueueProcessingType)}</li>
276 * </ul>
277 *
278 * @see #taskExecutor(Executor)
279 */
280 public Builder taskExecutorForCachedImages(Executor executorForCachedImages) {
281 if (threadPoolSize != DEFAULT_THREAD_POOL_SIZE || threadPriority != DEFAULT_THREAD_PRIORITY || tasksProcessingType != DEFAULT_TASK_PROCESSING_TYPE) {
282 L.w(WARNING_OVERLAP_EXECUTOR);
283 }
284
285 this.taskExecutorForCachedImages = executorForCachedImages;
286 return this;
287 }
288
289 /**
290 * Sets thread pool size for image display tasks.<br />
291 * Default value - {@link #DEFAULT_THREAD_POOL_SIZE this}
292 */
293 public Builder threadPoolSize(int threadPoolSize) {
294 if (taskExecutor != null || taskExecutorForCachedImages != null) {
295 L.w(WARNING_OVERLAP_EXECUTOR);
296 }
297
298 this.threadPoolSize = threadPoolSize;
299 return this;
300 }
301
302 /**
303 * Sets the priority for image loading threads. Should be <b>NOT</b> greater than {@link Thread#MAX_PRIORITY} or
304 * less than {@link Thread#MIN_PRIORITY}<br />
305 * Default value - {@link #DEFAULT_THREAD_PRIORITY this}
306 */
307 public Builder threadPriority(int threadPriority) {
308 if (taskExecutor != null || taskExecutorForCachedImages != null) {
309 L.w(WARNING_OVERLAP_EXECUTOR);
310 }
311
312 if (threadPriority < Thread.MIN_PRIORITY) {
313 this.threadPriority = Thread.MIN_PRIORITY;
314 } else {
315 if (threadPriority > Thread.MAX_PRIORITY) {
316 this.threadPriority = Thread.MAX_PRIORITY;
317 } else {
318 this.threadPriority = threadPriority;
319 }
320 }
321 return this;
322 }
323
324 /**
325 * When you display an image in a small {@link android.widget.ImageView ImageView} and later you try to display
326 * this image (from identical URI) in a larger {@link android.widget.ImageView ImageView} so decoded image of
327 * bigger size will be cached in memory as a previous decoded image of smaller size.<br />
328 * So <b>the default behavior is to allow to cache multiple sizes of one image in memory</b>. You can
329 * <b>deny</b> it by calling <b>this</b> method: so when some image will be cached in memory then previous
330 * cached size of this image (if it exists) will be removed from memory cache before.
331 */
332 public Builder denyCacheImageMultipleSizesInMemory() {
333 this.denyCacheImageMultipleSizesInMemory = true;
334 return this;
335 }
336
337 /**
338 * Sets type of queue processing for tasks for loading and displaying images.<br />
339 * Default value - {@link QueueProcessingType#FIFO}
340 */
341 public Builder tasksProcessingOrder(QueueProcessingType tasksProcessingType) {
342 if (taskExecutor != null || taskExecutorForCachedImages != null) {
343 L.w(WARNING_OVERLAP_EXECUTOR);
344 }
345
346 this.tasksProcessingType = tasksProcessingType;
347 return this;
348 }
349
350 /**
351 * Sets maximum memory cache size for {@link android.graphics.Bitmap bitmaps} (in bytes).<br />
352 * Default value - 1/8 of available app memory.<br />
353 * <b>NOTE:</b> If you use this method then
354 * {@link com.nostra13.universalimageloader.cache.memory.impl.LruMemoryCache LruMemoryCache} will be used as
355 * memory cache. You can use {@link #memoryCache(MemoryCache)} method to set your own implementation of
356 * {@link MemoryCache}.
357 */
358 public Builder memoryCacheSize(int memoryCacheSize) {
359 if (memoryCacheSize <= 0) throw new IllegalArgumentException("memoryCacheSize must be a positive number");
360
361 if (memoryCache != null) {
362 L.w(WARNING_OVERLAP_MEMORY_CACHE);
363 }
364
365 this.memoryCacheSize = memoryCacheSize;
366 return this;
367 }
368
369 /**
370 * Sets maximum memory cache size (in percent of available app memory) for {@link android.graphics.Bitmap
371 * bitmaps}.<br />
372 * Default value - 1/8 of available app memory.<br />
373 * <b>NOTE:</b> If you use this method then
374 * {@link com.nostra13.universalimageloader.cache.memory.impl.LruMemoryCache LruMemoryCache} will be used as
375 * memory cache. You can use {@link #memoryCache(MemoryCache)} method to set your own implementation of
376 * {@link MemoryCache}.
377 */
378 public Builder memoryCacheSizePercentage(int availableMemoryPercent) {
379 if (availableMemoryPercent <= 0 || availableMemoryPercent >= 100) {
380 throw new IllegalArgumentException("availableMemoryPercent must be in range (0 < % < 100)");
381 }
382
383 if (memoryCache != null) {
384 L.w(WARNING_OVERLAP_MEMORY_CACHE);
385 }
386
387 long availableMemory = Runtime.getRuntime().maxMemory();
388 memoryCacheSize = (int) (availableMemory * (availableMemoryPercent / 100f));
389 return this;
390 }
391
392 /**
393 * Sets memory cache for {@link android.graphics.Bitmap bitmaps}.<br />
394 * Default value - {@link com.nostra13.universalimageloader.cache.memory.impl.LruMemoryCache LruMemoryCache}
395 * with limited memory cache size (size = 1/8 of available app memory)<br />
396 * <br />
397 * <b>NOTE:</b> If you set custom memory cache then following configuration option will not be considered:
398 * <ul>
399 * <li>{@link #memoryCacheSize(int)}</li>
400 * </ul>
401 */
402 public Builder memoryCache(MemoryCache memoryCache) {
403 if (memoryCacheSize != 0) {
404 L.w(WARNING_OVERLAP_MEMORY_CACHE);
405 }
406
407 this.memoryCache = memoryCache;
408 return this;
409 }
410
411 /** @deprecated Use {@link #diskCacheSize(int)} instead */
412 @Deprecated
413 public Builder discCacheSize(int maxCacheSize) {
414 return diskCacheSize(maxCacheSize);
415 }
416
417 /**
418 * Sets maximum disk cache size for images (in bytes).<br />
419 * By default: disk cache is unlimited.<br />
420 * <b>NOTE:</b> If you use this method then
421 * {@link com.nostra13.universalimageloader.cache.disc.impl.ext.LruDiscCache LruDiscCache}
422 * will be used as disk cache. You can use {@link #diskCache(DiskCache)} method for introduction your own
423 * implementation of {@link DiskCache}
424 */
425 public Builder diskCacheSize(int maxCacheSize) {
426 if (maxCacheSize <= 0) throw new IllegalArgumentException("maxCacheSize must be a positive number");
427
428 if (diskCache != null) {
429 L.w(WARNING_OVERLAP_DISK_CACHE_PARAMS);
430 }
431
432 this.diskCacheSize = maxCacheSize;
433 return this;
434 }
435
436 /** @deprecated Use {@link #diskCacheFileCount(int)} instead */
437 @Deprecated
438 public Builder discCacheFileCount(int maxFileCount) {
439 return diskCacheFileCount(maxFileCount);
440 }
441
442 /**
443 * Sets maximum file count in disk cache directory.<br />
444 * By default: disk cache is unlimited.<br />
445 * <b>NOTE:</b> If you use this method then
446 * {@link com.nostra13.universalimageloader.cache.disc.impl.ext.LruDiscCache LruDiscCache}
447 * will be used as disk cache. You can use {@link #diskCache(DiskCache)} method for introduction your own
448 * implementation of {@link DiskCache}
449 */
450 public Builder diskCacheFileCount(int maxFileCount) {
451 if (maxFileCount <= 0) throw new IllegalArgumentException("maxFileCount must be a positive number");
452
453 if (diskCache != null) {
454 L.w(WARNING_OVERLAP_DISK_CACHE_PARAMS);
455 }
456
457 this.diskCacheFileCount = maxFileCount;
458 return this;
459 }
460
461 /** @deprecated Use {@link #diskCacheFileNameGenerator(com.nostra13.universalimageloader.cache.disc.naming.FileNameGenerator)} */
462 @Deprecated
463 public Builder discCacheFileNameGenerator(FileNameGenerator fileNameGenerator) {
464 return diskCacheFileNameGenerator(fileNameGenerator);
465 }
466
467 /**
468 * Sets name generator for files cached in disk cache.<br />
469 * Default value -
470 * {@link com.nostra13.universalimageloader.core.DefaultConfigurationFactory#createFileNameGenerator()
471 * DefaultConfigurationFactory.createFileNameGenerator()}
472 */
473 public Builder diskCacheFileNameGenerator(FileNameGenerator fileNameGenerator) {
474 if (diskCache != null) {
475 L.w(WARNING_OVERLAP_DISK_CACHE_NAME_GENERATOR);
476 }
477
478 this.diskCacheFileNameGenerator = fileNameGenerator;
479 return this;
480 }
481
482 /** @deprecated Use {@link #diskCache(com.nostra13.universalimageloader.cache.disc.DiskCache)} */
483 @Deprecated
484 public Builder discCache(DiskCache diskCache) {
485 return diskCache(diskCache);
486 }
487
488 /**
489 * Sets disk cache for images.<br />
490 * Default value - {@link com.nostra13.universalimageloader.cache.disc.impl.UnlimitedDiscCache
491 * BaseDiscCache}. Cache directory is defined by
492 * {@link com.nostra13.universalimageloader.utils.StorageUtils#getCacheDirectory(Context)
493 * StorageUtils.getCacheDirectory(Context)}.<br />
494 * <br />
495 * <b>NOTE:</b> If you set custom disk cache then following configuration option will not be considered:
496 * <ul>
497 * <li>{@link #diskCacheSize(int)}</li>
498 * <li>{@link #diskCacheFileCount(int)}</li>
499 * <li>{@link #diskCacheFileNameGenerator(FileNameGenerator)}</li>
500 * </ul>
501 */
502 public Builder diskCache(DiskCache diskCache) {
503 if (diskCacheSize > 0 || diskCacheFileCount > 0) {
504 L.w(WARNING_OVERLAP_DISK_CACHE_PARAMS);
505 }
506 if (diskCacheFileNameGenerator != null) {
507 L.w(WARNING_OVERLAP_DISK_CACHE_NAME_GENERATOR);
508 }
509
510 this.diskCache = diskCache;
511 return this;
512 }
513
514 /**
515 * Sets utility which will be responsible for downloading of image.<br />
516 * Default value -
517 * {@link com.nostra13.universalimageloader.core.DefaultConfigurationFactory#createImageDownloader(Context)
518 * DefaultConfigurationFactory.createImageDownloader()}
519 */
520 public Builder imageDownloader(ImageDownloader imageDownloader) {
521 this.downloader = imageDownloader;
522 return this;
523 }
524
525 /**
526 * Sets utility which will be responsible for decoding of image stream.<br />
527 * Default value -
528 * {@link com.nostra13.universalimageloader.core.DefaultConfigurationFactory#createImageDecoder(boolean)
529 * DefaultConfigurationFactory.createImageDecoder()}
530 */
531 public Builder imageDecoder(ImageDecoder imageDecoder) {
532 this.decoder = imageDecoder;
533 return this;
534 }
535
536 /**
537 * Sets default {@linkplain DisplayImageOptions display image options} for image displaying. These options will
538 * be used for every {@linkplain ImageLoader#displayImage(String, android.widget.ImageView) image display call}
539 * without passing custom {@linkplain DisplayImageOptions options}<br />
540 * Default value - {@link DisplayImageOptions#createSimple() Simple options}
541 */
542 public Builder defaultDisplayImageOptions(DisplayImageOptions defaultDisplayImageOptions) {
543 this.defaultDisplayImageOptions = defaultDisplayImageOptions;
544 return this;
545 }
546
547 /**
548 * Enables detail logging of {@link ImageLoader} work. To prevent detail logs don't call this method.
549 * Consider {@link com.nostra13.universalimageloader.utils.L#disableLogging()} to disable
550 * ImageLoader logging completely (even error logs)
551 */
552 public Builder writeDebugLogs() {
553 this.writeLogs = true;
554 return this;
555 }
556
557 /** Builds configured {@link ImageLoaderConfiguration} object */
558 public ImageLoaderConfiguration build() {
559 initEmptyFieldsWithDefaultValues();
560 return new ImageLoaderConfiguration(this);
561 }
562
563 private void initEmptyFieldsWithDefaultValues() {
564 if (taskExecutor == null) {
565 taskExecutor = DefaultConfigurationFactory
566 .createExecutor(threadPoolSize, threadPriority, tasksProcessingType);
567 } else {
568 customExecutor = true;
569 }
570 if (taskExecutorForCachedImages == null) {
571 taskExecutorForCachedImages = DefaultConfigurationFactory
572 .createExecutor(threadPoolSize, threadPriority, tasksProcessingType);
573 } else {
574 customExecutorForCachedImages = true;
575 }
576 if (diskCache == null) {
577 if (diskCacheFileNameGenerator == null) {
578 diskCacheFileNameGenerator = DefaultConfigurationFactory.createFileNameGenerator();
579 }
580 diskCache = DefaultConfigurationFactory
581 .createDiskCache(context, diskCacheFileNameGenerator, diskCacheSize, diskCacheFileCount);
582 }
583 if (memoryCache == null) {
584 memoryCache = DefaultConfigurationFactory.createMemoryCache(memoryCacheSize);
585 }
586 if (denyCacheImageMultipleSizesInMemory) {
587 memoryCache = new FuzzyKeyMemoryCache(memoryCache, MemoryCacheUtils.createFuzzyKeyComparator());
588 }
589 if (downloader == null) {
590 downloader = DefaultConfigurationFactory.createImageDownloader(context);
591 }
592 if (decoder == null) {
593 decoder = DefaultConfigurationFactory.createImageDecoder(writeLogs);
594 }
595 if (defaultDisplayImageOptions == null) {
596 defaultDisplayImageOptions = DisplayImageOptions.createSimple();
597 }
598 }
599 }
600
601 /**
602 * Decorator. Prevents downloads from network (throws {@link IllegalStateException exception}).<br />
603 * In most cases this downloader shouldn't be used directly.
604 *
605 * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
606 * @since 1.8.0
607 */
608 private static class NetworkDeniedImageDownloader implements ImageDownloader {
609
610 private final ImageDownloader wrappedDownloader;
611
612 public NetworkDeniedImageDownloader(ImageDownloader wrappedDownloader) {
613 this.wrappedDownloader = wrappedDownloader;
614 }
615
616 @Override
617 public InputStream getStream(String imageUri, Object extra) throws IOException {
618 switch (Scheme.ofUri(imageUri)) {
619 case HTTP:
620 case HTTPS:
621 throw new IllegalStateException();
622 default:
623 return wrappedDownloader.getStream(imageUri, extra);
624 }
625 }
626 }
627
628 /**
629 * Decorator. Handles <a href="http://code.google.com/p/android/issues/detail?id=6066">this problem</a> on slow networks
630 * using {@link com.nostra13.universalimageloader.core.assist.FlushedInputStream}.
631 *
632 * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
633 * @since 1.8.1
634 */
635 private static class SlowNetworkImageDownloader implements ImageDownloader {
636
637 private final ImageDownloader wrappedDownloader;
638
639 public SlowNetworkImageDownloader(ImageDownloader wrappedDownloader) {
640 this.wrappedDownloader = wrappedDownloader;
641 }
642
643 @Override
644 public InputStream getStream(String imageUri, Object extra) throws IOException {
645 InputStream imageStream = wrappedDownloader.getStream(imageUri, extra);
646 switch (Scheme.ofUri(imageUri)) {
647 case HTTP:
648 case HTTPS:
649 return new FlushedInputStream(imageStream);
650 default:
651 return imageStream;
652 }
653 }
654 }
655 }
Display Options
每一个ImageLoader.displayImage(...)都可以使用Display Options。
DisplayImageOptions options = new DisplayImageOptions.Builder()
.showImageOnLoading(R.drawable.ic_stub) // resource or drawable
.showImageForEmptyUri(R.drawable.ic_empty) // resource or drawable
.showImageOnFail(R.drawable.ic_error) // resource or drawable
.resetViewBeforeLoading(false) // default
.delayBeforeLoading(1000)
.cacheInMemory(false) // default
.cacheOnDisk(false) // default
.preProcessor(...)
.postProcessor(...)
.extraForDownloader(...)
.considerExifParams(false) // default
.imageScaleType(ImageScaleType.IN_SAMPLE_POWER_OF_2) // default
.bitmapConfig(Bitmap.Config.ARGB_8888) // default
.decodingOptions(...)
.displayer(new SimpleBitmapDisplayer()) // default
.handler(new Handler()) // default
.build();
Display Options的主要职责就是记录相关的配置，它的内部其实就是一些字段的集合（如下面的源代码）。它有一个builder的内部类，这个类中的字段跟DisplayOption中的字段完全一致，它有一些默认值，通过修改builder可以配置DisplayOptions。
1 public final class DisplayImageOptions {
2
3 private final int imageResOnLoading;
4 private final int imageResForEmptyUri;
5 private final int imageResOnFail;
6 private final Drawable imageOnLoading;
7 private final Drawable imageForEmptyUri;
8 private final Drawable imageOnFail;
9 private final boolean resetViewBeforeLoading;
10 private final boolean cacheInMemory;
11 private final boolean cacheOnDisk;
12 private final ImageScaleType imageScaleType;
13 private final Options decodingOptions;
14 private final int delayBeforeLoading;
15 private final boolean considerExifParams;
16 private final Object extraForDownloader;
17 private final BitmapProcessor preProcessor;
18 private final BitmapProcessor postProcessor;
19 private final BitmapDisplayer displayer;
20 private final Handler handler;
21 private final boolean isSyncLoading;
22
23 private DisplayImageOptions(Builder builder) {
24 imageResOnLoading = builder.imageResOnLoading;
25 imageResForEmptyUri = builder.imageResForEmptyUri;
26 imageResOnFail = builder.imageResOnFail;
27 imageOnLoading = builder.imageOnLoading;
28 imageForEmptyUri = builder.imageForEmptyUri;
29 imageOnFail = builder.imageOnFail;
30 resetViewBeforeLoading = builder.resetViewBeforeLoading;
31 cacheInMemory = builder.cacheInMemory;
32 cacheOnDisk = builder.cacheOnDisk;
33 imageScaleType = builder.imageScaleType;
34 decodingOptions = builder.decodingOptions;
35 delayBeforeLoading = builder.delayBeforeLoading;
36 considerExifParams = builder.considerExifParams;
37 extraForDownloader = builder.extraForDownloader;
38 preProcessor = builder.preProcessor;
39 postProcessor = builder.postProcessor;
40 displayer = builder.displayer;
41 handler = builder.handler;
42 isSyncLoading = builder.isSyncLoading;
43 }
44
45 public boolean shouldShowImageOnLoading() {
46 return imageOnLoading != null || imageResOnLoading != 0;
47 }
48
49 public boolean shouldShowImageForEmptyUri() {
50 return imageForEmptyUri != null || imageResForEmptyUri != 0;
51 }
52
53 public boolean shouldShowImageOnFail() {
54 return imageOnFail != null || imageResOnFail != 0;
55 }
56
57 public boolean shouldPreProcess() {
58 return preProcessor != null;
59 }
60
61 public boolean shouldPostProcess() {
62 return postProcessor != null;
63 }
64
65 public boolean shouldDelayBeforeLoading() {
66 return delayBeforeLoading > 0;
67 }
68
69 public Drawable getImageOnLoading(Resources res) {
70 return imageResOnLoading != 0 ? res.getDrawable(imageResOnLoading) : imageOnLoading;
71 }
72
73 public Drawable getImageForEmptyUri(Resources res) {
74 return imageResForEmptyUri != 0 ? res.getDrawable(imageResForEmptyUri) : imageForEmptyUri;
75 }
76
77 public Drawable getImageOnFail(Resources res) {
78 return imageResOnFail != 0 ? res.getDrawable(imageResOnFail) : imageOnFail;
79 }
80
81 public boolean isResetViewBeforeLoading() {
82 return resetViewBeforeLoading;
83 }
84
85 public boolean isCacheInMemory() {
86 return cacheInMemory;
87 }
88
89 public boolean isCacheOnDisk() {
90 return cacheOnDisk;
91 }
92
93 public ImageScaleType getImageScaleType() {
94 return imageScaleType;
95 }
96
97 public Options getDecodingOptions() {
98 return decodingOptions;
99 }
100
101 public int getDelayBeforeLoading() {
102 return delayBeforeLoading;
103 }
104
105 public boolean isConsiderExifParams() {
106 return considerExifParams;
107 }
108
109 public Object getExtraForDownloader() {
110 return extraForDownloader;
111 }
112
113 public BitmapProcessor getPreProcessor() {
114 return preProcessor;
115 }
116
117 public BitmapProcessor getPostProcessor() {
118 return postProcessor;
119 }
120
121 public BitmapDisplayer getDisplayer() {
122 return displayer;
123 }
124
125 public Handler getHandler() {
126 return handler;
127 }
128
129 boolean isSyncLoading() {
130 return isSyncLoading;
131 }
132
133 /**
134 * Builder for {@link DisplayImageOptions}
135 *
136 * @author Sergey Tarasevich (nostra13[at]gmail[dot]com)
137 */
138 public static class Builder {
139 private int imageResOnLoading = 0;
140 private int imageResForEmptyUri = 0;
141 private int imageResOnFail = 0;
142 private Drawable imageOnLoading = null;
143 private Drawable imageForEmptyUri = null;
144 private Drawable imageOnFail = null;
145 private boolean resetViewBeforeLoading = false;
146 private boolean cacheInMemory = false;
147 private boolean cacheOnDisk = false;
148 private ImageScaleType imageScaleType = ImageScaleType.IN_SAMPLE_POWER_OF_2;
149 private Options decodingOptions = new Options();
150 private int delayBeforeLoading = 0;
151 private boolean considerExifParams = false;
152 private Object extraForDownloader = null;
153 private BitmapProcessor preProcessor = null;
154 private BitmapProcessor postProcessor = null;
155 private BitmapDisplayer displayer = DefaultConfigurationFactory.createBitmapDisplayer();
156 private Handler handler = null;
157 private boolean isSyncLoading = false;
158
159 public Builder() {
160 decodingOptions.inPurgeable = true;
161 decodingOptions.inInputShareable = true;
162 }
163
164 /**
165 * Stub image will be displayed in {@link com.nostra13.universalimageloader.core.imageaware.ImageAware
166 * image aware view} during image loading
167 *
168 * @param imageRes Stub image resource
169 * @deprecated Use {@link #showImageOnLoading(int)} instead
170 */
171 @Deprecated
172 public Builder showStubImage(int imageRes) {
173 imageResOnLoading = imageRes;
174 return this;
175 }
176
177 /**
178 * Incoming image will be displayed in {@link com.nostra13.universalimageloader.core.imageaware.ImageAware
179 * image aware view} during image loading
180 *
181 * @param imageRes Image resource
182 */
183 public Builder showImageOnLoading(int imageRes) {
184 imageResOnLoading = imageRes;
185 return this;
186 }
187
188 /**
189 * Incoming drawable will be displayed in {@link com.nostra13.universalimageloader.core.imageaware.ImageAware
190 * image aware view} during image loading.
191 * This option will be ignored if {@link DisplayImageOptions.Builder#showImageOnLoading(int)} is set.
192 */
193 public Builder showImageOnLoading(Drawable drawable) {
194 imageOnLoading = drawable;
195 return this;
196 }
197
198 /**
199 * Incoming image will be displayed in {@link com.nostra13.universalimageloader.core.imageaware.ImageAware
200 * image aware view} if empty URI (null or empty
201 * string) will be passed to <b>ImageLoader.displayImage(...)</b> method.
202 *
203 * @param imageRes Image resource
204 */
205 public Builder showImageForEmptyUri(int imageRes) {
206 imageResForEmptyUri = imageRes;
207 return this;
208 }
209
210 /**
211 * Incoming drawable will be displayed in {@link com.nostra13.universalimageloader.core.imageaware.ImageAware
212 * image aware view} if empty URI (null or empty
213 * string) will be passed to <b>ImageLoader.displayImage(...)</b> method.
214 * This option will be ignored if {@link DisplayImageOptions.Builder#showImageForEmptyUri(int)} is set.
215 */
216 public Builder showImageForEmptyUri(Drawable drawable) {
217 imageForEmptyUri = drawable;
218 return this;
219 }
220
221 /**
222 * Incoming image will be displayed in {@link com.nostra13.universalimageloader.core.imageaware.ImageAware
223 * image aware view} if some error occurs during
224 * requested image loading/decoding.
225 *
226 * @param imageRes Image resource
227 */
228 public Builder showImageOnFail(int imageRes) {
229 imageResOnFail = imageRes;
230 return this;
231 }
232
233 /**
234 * Incoming drawable will be displayed in {@link com.nostra13.universalimageloader.core.imageaware.ImageAware
235 * image aware view} if some error occurs during
236 * requested image loading/decoding.
237 * This option will be ignored if {@link DisplayImageOptions.Builder#showImageOnFail(int)} is set.
238 */
239 public Builder showImageOnFail(Drawable drawable) {
240 imageOnFail = drawable;
241 return this;
242 }
243
244 /**
245 * {@link com.nostra13.universalimageloader.core.imageaware.ImageAware
246 * image aware view} will be reset (set <b>null</b>) before image loading start
247 *
248 * @deprecated Use {@link #resetViewBeforeLoading(boolean) resetViewBeforeLoading(true)} instead
249 */
250 public Builder resetViewBeforeLoading() {
251 resetViewBeforeLoading = true;
252 return this;
253 }
254
255 /**
256 * Sets whether {@link com.nostra13.universalimageloader.core.imageaware.ImageAware
257 * image aware view} will be reset (set <b>null</b>) before image loading start
258 */
259 public Builder resetViewBeforeLoading(boolean resetViewBeforeLoading) {
260 this.resetViewBeforeLoading = resetViewBeforeLoading;
261 return this;
262 }
263
264 /**
265 * Loaded image will be cached in memory
266 *
267 * @deprecated Use {@link #cacheInMemory(boolean) cacheInMemory(true)} instead
268 */
269 @Deprecated
270 public Builder cacheInMemory() {
271 cacheInMemory = true;
272 return this;
273 }
274
275 /** Sets whether loaded image will be cached in memory */
276 public Builder cacheInMemory(boolean cacheInMemory) {
277 this.cacheInMemory = cacheInMemory;
278 return this;
279 }
280
281 /**
282 * Loaded image will be cached on disk
283 *
284 * @deprecated Use {@link #cacheOnDisk(boolean) cacheOnDisk(true)} instead
285 */
286 @Deprecated
287 public Builder cacheOnDisc() {
288 return cacheOnDisk(true);
289 }
290
291 /**
292 * Sets whether loaded image will be cached on disk
293 *
294 * @deprecated Use {@link #cacheOnDisk(boolean)} instead
295 */
296 @Deprecated
297 public Builder cacheOnDisc(boolean cacheOnDisk) {
298 return cacheOnDisk(cacheOnDisk);
299 }
300
301 /** Sets whether loaded image will be cached on disk */
302 public Builder cacheOnDisk(boolean cacheOnDisk) {
303 this.cacheOnDisk = cacheOnDisk;
304 return this;
305 }
306
307 /**
308 * Sets {@linkplain ImageScaleType scale type} for decoding image. This parameter is used while define scale
309 * size for decoding image to Bitmap. Default value - {@link ImageScaleType#IN_SAMPLE_POWER_OF_2}
310 */
311 public Builder imageScaleType(ImageScaleType imageScaleType) {
312 this.imageScaleType = imageScaleType;
313 return this;
314 }
315
316 /** Sets {@link Bitmap.Config bitmap config} for image decoding. Default value - {@link Bitmap.Config#ARGB_8888} */
317 public Builder bitmapConfig(Bitmap.Config bitmapConfig) {
318 if (bitmapConfig == null) throw new IllegalArgumentException("bitmapConfig can't be null");
319 decodingOptions.inPreferredConfig = bitmapConfig;
320 return this;
321 }
322
323 /**
324 * Sets options for image decoding.<br />
325 * <b>NOTE:</b> {@link Options#inSampleSize} of incoming options will <b>NOT</b> be considered. Library
326 * calculate the most appropriate sample size itself according yo {@link #imageScaleType(ImageScaleType)}
327 * options.<br />
328 * <b>NOTE:</b> This option overlaps {@link #bitmapConfig(android.graphics.Bitmap.Config) bitmapConfig()}
329 * option.
330 */
331 public Builder decodingOptions(Options decodingOptions) {
332 if (decodingOptions == null) throw new IllegalArgumentException("decodingOptions can't be null");
333 this.decodingOptions = decodingOptions;
334 return this;
335 }
336
337 /** Sets delay time before starting loading task. Default - no delay. */
338 public Builder delayBeforeLoading(int delayInMillis) {
339 this.delayBeforeLoading = delayInMillis;
340 return this;
341 }
342
343 /** Sets auxiliary object which will be passed to {@link ImageDownloader#getStream(String, Object)} */
344 public Builder extraForDownloader(Object extra) {
345 this.extraForDownloader = extra;
346 return this;
347 }
348
349 /** Sets whether ImageLoader will consider EXIF parameters of JPEG image (rotate, flip) */
350 public Builder considerExifParams(boolean considerExifParams) {
351 this.considerExifParams = considerExifParams;
352 return this;
353 }
354
355 /**
356 * Sets bitmap processor which will be process bitmaps before they will be cached in memory. So memory cache
357 * will contain bitmap processed by incoming preProcessor.<br />
358 * Image will be pre-processed even if caching in memory is disabled.
359 */
360 public Builder preProcessor(BitmapProcessor preProcessor) {
361 this.preProcessor = preProcessor;
362 return this;
363 }
364
365 /**
366 * Sets bitmap processor which will be process bitmaps before they will be displayed in
367 * {@link com.nostra13.universalimageloader.core.imageaware.ImageAware image aware view} but
368 * after they'll have been saved in memory cache.
369 */
370 public Builder postProcessor(BitmapProcessor postProcessor) {
371 this.postProcessor = postProcessor;
372 return this;
373 }
374
375 /**
376 * Sets custom {@link BitmapDisplayer displayer} for image loading task. Default value -
377 * {@link DefaultConfigurationFactory#createBitmapDisplayer()}
378 */
379 public Builder displayer(BitmapDisplayer displayer) {
380 if (displayer == null) throw new IllegalArgumentException("displayer can't be null");
381 this.displayer = displayer;
382 return this;
383 }
384
385 Builder syncLoading(boolean isSyncLoading) {
386 this.isSyncLoading = isSyncLoading;
387 return this;
388 }
389
390 /**
391 * Sets custom {@linkplain Handler handler} for displaying images and firing {@linkplain ImageLoadingListener
392 * listener} events.
393 */
394 public Builder handler(Handler handler) {
395 this.handler = handler;
396 return this;
397 }
398
399 /** Sets all options equal to incoming options */
400 public Builder cloneFrom(DisplayImageOptions options) {
401 imageResOnLoading = options.imageResOnLoading;
402 imageResForEmptyUri = options.imageResForEmptyUri;
403 imageResOnFail = options.imageResOnFail;
404 imageOnLoading = options.imageOnLoading;
405 imageForEmptyUri = options.imageForEmptyUri;
406 imageOnFail = options.imageOnFail;
407 resetViewBeforeLoading = options.resetViewBeforeLoading;
408 cacheInMemory = options.cacheInMemory;
409 cacheOnDisk = options.cacheOnDisk;
410 imageScaleType = options.imageScaleType;
411 decodingOptions = options.decodingOptions;
412 delayBeforeLoading = options.delayBeforeLoading;
413 considerExifParams = options.considerExifParams;
414 extraForDownloader = options.extraForDownloader;
415 preProcessor = options.preProcessor;
416 postProcessor = options.postProcessor;
417 displayer = options.displayer;
418 handler = options.handler;
419 isSyncLoading = options.isSyncLoading;
420 return this;
421 }
422
423 /** Builds configured {@link DisplayImageOptions} object */
424 public DisplayImageOptions build() {
425 return new DisplayImageOptions(this);
426 }
427 }
428
429 /**
430 * Creates options appropriate for single displaying:
431 * <ul>
432 * <li>View will <b>not</b> be reset before loading</li>
433 * <li>Loaded image will <b>not</b> be cached in memory</li>
434 * <li>Loaded image will <b>not</b> be cached on disk</li>
435 * <li>{@link ImageScaleType#IN_SAMPLE_POWER_OF_2} decoding type will be used</li>
436 * <li>{@link Bitmap.Config#ARGB_8888} bitmap config will be used for image decoding</li>
437 * <li>{@link SimpleBitmapDisplayer} will be used for image displaying</li>
438 * </ul>
439 * <p/>
440 * These option are appropriate for simple single-use image (from drawables or from Internet) displaying.
441 */
442 public static DisplayImageOptions createSimple() {
443 return new Builder().build();
444 }
445 }
参考链接
http://blog.csdn.net/wangjinyu501/article/details/8091623
https://github.com/nostra13/Android-Universal-Image-Loader
http://www.intexsoft.com/blog/item/74-universal-image-loader-part-3.html
转载请注明本文地址： Android-Universal-Image-Loader三大组件DisplayImageOptions、ImageLoader、ImageLoaderConfiguration详解