public AsyncImageLoader(ImageView image, LruCache<String, Bitmap> lruCache,int width,int height) {  super();  this.image = image;  this.lruCache = lruCache;  this.width=width;this.height=width;}  @Override  protected Bitmap doInBackground(String... params) {  Bitmap bitmap = null;  bitmap = GetUserInfo.getBitmap(params[0]); if(width!=0&height!=0)bitmap=GetUserInfo.scaleImg(bitmap, width, height);addBitmapToMemoryCache(params[0], bitmap);  return bitmap;  }  @Override  protected void onPostExecute(Bitmap bitmap) {  image.setImageBitmap(bitmap);  }

package com.fangjie.weibo.util;
import android.graphics.Bitmap;
import android.os.AsyncTask;
import android.support.v4.util.LruCache;
import android.widget.ImageView;public class AsyncImageLoader extends AsyncTask<String, Void, Bitmap> {private ImageView image;  private LruCache<String, Bitmap> lruCache;  private int width;private int height;/** * 构造方法，需要把ImageView控件和LruCache 对象传进来 * @param image 加载图片到此 {@code}ImageView * @param lruCache 缓存图片的对象 */  public AsyncImageLoader(ImageView image, LruCache<String, Bitmap> lruCache,int width,int height) {  super();  this.image = image;  this.lruCache = lruCache;  this.width=width;this.height=width;}  @Override  protected Bitmap doInBackground(String... params) {  Bitmap bitmap = null;  bitmap = GetUserInfo.getBitmap(params[0]); if(width!=0&height!=0)bitmap=GetUserInfo.scaleImg(bitmap, width, height);addBitmapToMemoryCache(params[0], bitmap);  return bitmap;  }  @Override  protected void onPostExecute(Bitmap bitmap) {  image.setImageBitmap(bitmap);  }  //调用LruCache的put 方法将图片加入内存缓存中，要给这个图片一个key 方便下次从缓存中取出来  private void addBitmapToMemoryCache(String key, Bitmap bitmap) {  if (getBitmapFromMemoryCache(key) == null) {  lruCache.put(key, bitmap);  }  }  //调用Lrucache的get 方法从内存缓存中去图片  public Bitmap getBitmapFromMemoryCache(String key) {  return lruCache.get(key);  }
}

    private final int maxMemory = (int) Runtime.getRuntime().maxMemory();//获取当前应用程序所分配的最大内存  private final int cacheSize = maxMemory / 5;//只分5分之一用来做图片缓存  private LruCache<String, Bitmap> mLruCache = new LruCache<String, Bitmap>(  cacheSize) {   protected int sizeOf(String key, Bitmap bitmap) {//复写sizeof()方法  // replaced by getByteCount() in API 12  return bitmap.getRowBytes() * bitmap.getHeight() / 1024; //这里是按多少KB来算
        }  }; /*** * @param urlStr 所需要加载的图片的url，以String形式传进来，可以把这个url作为缓存图片的key* @param image ImageView 控件*/private void loadBitmap(String urlStr, ImageView image,int width,int height) {System.out.println(urlStr);AsyncImageLoader asyncLoader = new AsyncImageLoader(image, mLruCache,width,height);//什么一个异步图片加载对象Bitmap bitmap = asyncLoader.getBitmapFromMemoryCache(urlStr);//首先从内存缓存中获取图片if (bitmap != null) {image.setImageBitmap(bitmap);//如果缓存中存在这张图片则直接设置给ImageView} else {image.setImageResource(R.drawable.user_head);//否则先设置成默认的图片asyncLoader.execute(urlStr);//然后执行异步任务AsycnTask 去网上加载图片
        }}