实现imageloader全局配置和缓存

public class App extends Application {
private Context context;

@Override
public void onCreate() {
    super.onCreate();
    context = this;
    //得到绝对路径
    String SDpath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/images";
    //创建流
    File file = new File(SDpath);
    //创建全局配置
    ImageLoaderConfiguration configuration = new ImageLoaderConfiguration.Builder(context)
            .threadPriority(2)
            .threadPoolSize(3)
            .memoryCacheExtraOptions(480, 800)
            .diskCacheExtraOptions(480, 800, null)
            .diskCache(new UnlimitedDiskCache(file))
            .build();
    ImageLoader.getInstance().init(configuration);
}

public static DisplayImageOptions getoption() {
    DisplayImageOptions options = new DisplayImageOptions.Builder()
            .cacheOnDisk(true)
            .cacheInMemory(true)
            .displayer(new FadeInBitmapDisplayer(500))
            .build();
    return options;
}

}