</pre><p>布局文件activity_main.xml</p><p></p><pre name="code" class="html"><?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:id="@+id/activity_main"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="@dimen/activity_vertical_margin"
android:paddingLeft="@dimen/activity_horizontal_margin"
android:paddingRight="@dimen/activity_horizontal_margin"
android:paddingTop="@dimen/activity_vertical_margin"
tools:context="com.dsy.selectpicture.MainActivity">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="相机"
android:id="@+id/xiangji"/>
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="图库"
android:layout_alignParentTop="true"
android:layout_toRightOf="@+id/xiangji"
android:layout_toEndOf="@+id/xiangji"
android:layout_marginLeft="25dp"
android:layout_marginStart="25dp"
android:id="@+id/tuku"/>
<ImageView
android:layout_width="wrap_content"
android:layout_marginTop="20dp"
android:layout_height="wrap_content"
android:src="@mipmap/ic_launcher"
android:layout_centerHorizontal="true"
android:id="@+id/iv"
android:layout_below="@+id/xiangji"/>
</RelativeLayout>
然后是MainActivity.java
import android.content.Intent;
import android.graphics.Bitmap;
import android.media.ThumbnailUtils;
import android.net.Uri;
import android.provider.MediaStore;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.ImageView;
import java.io.File;
import java.io.FileOutputStream;
public class MainActivity extends AppCompatActivity {
private final int SELECT_PICTURE = 1; // 从图库中选择图片
private final int SELECT_CAMER = 2; // 用相机拍摄照片
private static final String PicName = "pic.jpg";
private String PicPath;
private ImageView iv;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
iv= (ImageView) findViewById(R.id.iv);
PicPath = BitmapUtil.getImgCacheDir(this);//获取图片缓存路径
findViewById(R.id.xiangji).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// 进入相机
Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
//设置照片保存路径
intent.putExtra(MediaStore.EXTRA_OUTPUT, Uri.fromFile(new File(PicPath, PicName)));
startActivityForResult(intent, SELECT_CAMER);
}
});
findViewById(R.id.tuku).setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// 进入图库
// Intent intent = new Intent(Intent.ACTION_GET_CONTENT);
// intent.addCategory(Intent.CATEGORY_OPENABLE);
// intent.setType("image/*");
// startActivityForResult(intent, SELECT_PICTURE);
Intent intent = new Intent(Intent.ACTION_PICK,
android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);
intent.setDataAndType(MediaStore.Images.Media.EXTERNAL_CONTENT_URI,"image/*");
startActivityForResult(intent, SELECT_PICTURE);
}
});
}
@Override
protected void onActivityResult(final int requestCode, int resultCode,
final Intent data) {
if (resultCode == RESULT_OK) {
//启动线程压缩图片
new Thread(new Runnable() {
//开启线程保持文件到本地
@Override
public void run() {
Bitmap bitmap = null;
//压缩图片
if (requestCode == SELECT_CAMER) {
bitmap = BitmapUtil.compressImageFromFile(PicPath + "/"+PicName);
} else if (requestCode == SELECT_PICTURE) {
bitmap = BitmapUtil.compressImageFromUri(MainActivity.this, data.getData());
}
//获取图片缩略图并显示
final Bitmap thumb=ThumbnailUtils.extractThumbnail(bitmap, 300, 300);
runOnUiThread(new Runnable() {
@Override
public void run() {
iv.setImageBitmap(thumb);
}
});
try {
//保存压缩后的图片到本地
File f = new File(PicPath, PicName);
f.createNewFile();
FileOutputStream fOut = new FileOutputStream(f);
if (bitmap != null) {
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, fOut);
}
fOut.flush();
fOut.close();
} catch (Exception e1) {
e1.printStackTrace();
}
}
}).start();
}
super.onActivityResult(requestCode, resultCode, data);
}
}
从图库选择的图片然后获取其绝对路径，这里踩了很多坑，多次测试找到了可行的解决工具类
import android.content.ContentUris;
import android.content.Context;
import android.database.Cursor;
import android.net.Uri;
import android.os.Build;
import android.os.Environment;
import android.provider.DocumentsContract;
import android.provider.MediaStore;
import android.text.TextUtils;
import android.util.Log;
public class PictureUtil {
public static String getPicturePath(Context context, Uri uri) {
String path = getPath(context, uri);
if (TextUtils.isEmpty(path)) {
path = selectImage(context, uri);
}
return path;
}
/**
* 获取图库图片路径
*/
public static String selectImage(Context context, Uri selectedImage) {
if (selectedImage != null) {
String uriStr = selectedImage.toString();
String path = uriStr.substring(10, uriStr.length());
if (path.startsWith("com.sec.android.gallery3d")) {
Log.e("=====", "It's auto backup pic path:" + selectedImage.toString());
return null;
}
}
String[] filePathColumn = {MediaStore.Images.Media.DATA};
Cursor cursor = context.getContentResolver().query(selectedImage, filePathColumn, null, null, null);
String picturePath = null;
if (cursor != null) {
cursor.moveToFirst();
int columnIndex = cursor.getColumnIndex(filePathColumn[0]);
picturePath = cursor.getString(columnIndex);
cursor.close();
}
return picturePath;
}
public static String getPath(final Context context, final Uri uri) {
// DocumentProvider
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {
if (DocumentsContract.isDocumentUri(context, uri)) {
// ExternalStorageProvider
if (isExternalStorageDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
if ("primary".equalsIgnoreCase(type)) {
return Environment.getExternalStorageDirectory() + "/" + split[1];
}
// TODO handle non-primary volumes
}
// DownloadsProvider
else if (isDownloadsDocument(uri)) {
final String id = DocumentsContract.getDocumentId(uri);
final Uri contentUri = ContentUris.withAppendedId(
Uri.parse("content://downloads/public_downloads"), Long.valueOf(id));
return getDataColumn(context, contentUri, null, null);
}
// MediaProvider
else if (isMediaDocument(uri)) {
final String docId = DocumentsContract.getDocumentId(uri);
final String[] split = docId.split(":");
final String type = split[0];
Uri contentUri = null;
if ("image".equals(type)) {
contentUri = MediaStore.Images.Media.EXTERNAL_CONTENT_URI;
} else if ("video".equals(type)) {
contentUri = MediaStore.Video.Media.EXTERNAL_CONTENT_URI;
} else if ("audio".equals(type)) {
contentUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
}
final String selection = "_id=?";
final String[] selectionArgs = new String[]{
split[1]
};
return getDataColumn(context, contentUri, selection, selectionArgs);
}
}
// MediaStore (and general)
else if ("content".equalsIgnoreCase(uri.getScheme())) {
// Return the remote address
if (isGooglePhotosUri(uri))
return uri.getLastPathSegment();
return getDataColumn(context, uri, null, null);
}
// File
else if ("file".equalsIgnoreCase(uri.getScheme())) {
return uri.getPath();
}
}
return null;
}
/**
* Get the value of the data column for this Uri. This is useful for
* MediaStore Uris, and other file-based ContentProviders.
*
* @param context The context.
* @param uri The Uri to query.
* @param selection (Optional) Filter used in the query.
* @param selectionArgs (Optional) Selection arguments used in the query.
* @return The value of the _data column, which is typically a file path.
*/
public static String getDataColumn(Context context, Uri uri, String selection,
String[] selectionArgs) {
Cursor cursor = null;
final String column = "_data";
final String[] projection = {
column
};
try {
cursor = context.getContentResolver().query(uri, projection, selection, selectionArgs,
null);
if (cursor != null && cursor.moveToFirst()) {
final int index = cursor.getColumnIndexOrThrow(column);
return cursor.getString(index);
}
} finally {
if (cursor != null)
cursor.close();
}
return null;
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is ExternalStorageProvider.
*/
public static boolean isExternalStorageDocument(Uri uri) {
return "com.android.externalstorage.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is DownloadsProvider.
*/
public static boolean isDownloadsDocument(Uri uri) {
return "com.android.providers.downloads.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is MediaProvider.
*/
public static boolean isMediaDocument(Uri uri) {
return "com.android.providers.media.documents".equals(uri.getAuthority());
}
/**
* @param uri The Uri to check.
* @return Whether the Uri authority is Google Photos.
*/
public static boolean isGooglePhotosUri(Uri uri) {
return "com.google.android.apps.photos.content".equals(uri.getAuthority());
}
}
最后是压缩图片的工具类
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Matrix;
import android.media.ExifInterface;
import android.net.Uri;
import android.os.Environment;
import android.util.Log;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
public class BitmapUtil {
public static String getImgCacheDir(Activity activity) {
if (Environment.MEDIA_MOUNTED.equals(Environment.getExternalStorageState())) {
return activity.getExternalCacheDir().getAbsolutePath();
} else {
return activity.getCacheDir().getAbsolutePath();
}
}
public static Bitmap compressImageFromFile(String srcPath) {
BitmapFactory.Options newOpts = new BitmapFactory.Options();
newOpts.inJustDecodeBounds = true;//只读边,不读内容
Bitmap bitmap = BitmapFactory.decodeFile(srcPath, newOpts);
newOpts.inJustDecodeBounds = false;
int w = newOpts.outWidth;
int h = newOpts.outHeight;
int degree = getBitmapDegree(srcPath);
float hh = 1000f;//
float ww = 800f;//
int be = 1;
if (w > h && w > ww) {
be = (int) (newOpts.outWidth / ww);
} else if (w < h && h > hh) {
be = (int) (newOpts.outHeight / hh);
}
if (be <= 0)
be = 1;
newOpts.inSampleSize = be;//设置采样率
newOpts.inPreferredConfig = Bitmap.Config.ARGB_8888;//该模式是默认的,可不设
newOpts.inPurgeable = true;// 同时设置才会有效
newOpts.inInputShareable = true;//。当系统内存不够时候图片自动被回收
bitmap = BitmapFactory.decodeFile(srcPath, newOpts);
if (degree != 0) {
bitmap = rotateBitmapByDegree(bitmap, degree);
}
// return compressImage(bitmap);//原来的方法调用了这个方法企图进行二次压缩
//其实是无效的,大家尽管尝试
ByteArrayOutputStream baos = new ByteArrayOutputStream();
bitmap.compress(Bitmap.CompressFormat.JPEG, 100, baos);//这里100的话表示不压缩质量
long length = baos.toByteArray().length;//读出图片的kb大小
Log.d("====", "图片压缩前大小：" + baos.toByteArray().length / 1024f);
if (length <= 2000000) {
return bitmap;//如果图片本身的大小已经小于这个大小了，就没必要进行压缩
}
int quality = 100;
//压缩图片大小至 2000000b（2000000/1000/1024≈1.9M） 以下，可以根据需要调整大小
while (baos.toByteArray().length > 2000000) {
quality = quality - 4;// 每次都减少4
baos.reset();// 重置baos即清空baos
if (quality <= 0) {
break;
}
bitmap.compress(Bitmap.CompressFormat.JPEG, quality, baos);
Log.d("====", "图片压缩后大小：" + baos.toByteArray().length / 1024f);
}
bitmap = BitmapFactory.decodeByteArray(baos.toByteArray(), 0, baos.toByteArray().length, newOpts);
return bitmap;
}
public static Bitmap compressImageFromUri(Context context, Uri uri) {
return compressImageFromFile(PictureUtil.getPicturePath(context, uri));
}
/**
* 读取图片的旋转的角度
*
* @param path 图片绝对路径
* @return 图片的旋转角度
*/
public static int getBitmapDegree(String path) {
int degree = 0;
try {
// 从指定路径下读取图片，并获取其EXIF信息
ExifInterface exifInterface = new ExifInterface(path);
// 获取图片的旋转信息
int orientation = exifInterface.getAttributeInt(ExifInterface.TAG_ORIENTATION, ExifInterface.ORIENTATION_NORMAL);
switch (orientation) {
case ExifInterface.ORIENTATION_ROTATE_90:
degree = 90;
break;
case ExifInterface.ORIENTATION_ROTATE_180:
degree = 180;
break;
case ExifInterface.ORIENTATION_ROTATE_270:
degree = 270;
break;
default:
}
} catch (IOException e) {
e.printStackTrace();
}
return degree;
}
/**
* 将图片按照某个角度进行旋转
*
* @param bm 需要旋转的图片
* @param degree 旋转角度
* @return 旋转后的图片
*/
private static Bitmap rotateBitmapByDegree(Bitmap bm, int degree) {
Bitmap bitmap = null;
// 根据旋转角度，生成旋转矩阵
Matrix matrix = new Matrix();
matrix.postRotate(degree);
try {
// 将原始图片按照旋转矩阵进行旋转，并得到新的图片
bitmap = Bitmap.createBitmap(bm, 0, 0, bm.getWidth(), bm.getHeight(), matrix, true);
} catch (OutOfMemoryError error) {
Log.e("ESA", "rotateBitmapByDegree decodeFile OutOfMemoryError." + error.getMessage());
}
if (bitmap == null) {
bitmap = bm;
}
if (bm != bitmap) {
bm.recycle();
}
return bitmap;
}
}
已经有很多开源的网络请求框架支持了上传文件功能，推荐okhttp