1、首先在當前程式的Application中呼叫ImageLoader的初始化init()方法

private void initImageLoader() {
		ImageLoaderConfiguration config = new ImageLoaderConfiguration.Builder(this).imageDownloader(
				new BaseImageDownloader(this, 60 * 1000, 60 * 1000)) // connectTimeout超時時間
				.build();
		ImageLoader.getInstance().init(config);
	}
 

2、下載圖片的引數選項配置

    /**
     * 呼叫該方法下載圖片
     * 配置imageLoader圖片選項
     * @param iv  顯示圖片控制元件
     * @param url  網路或本地圖片地址
     * @param defaultPic  預設圖片
     * @param isRound  true為圓形，false不處理
     * @param cacheOnDisk true快取到SD卡，false不快取到SD卡
     */
   public static void displayImages(ImageView iv,String url,int defaultPic,boolean isRound,boolean cacheOnDisk){
		 //配置一些圖片選項
		 DisplayImageOptions options = new DisplayImageOptions.Builder()
		 .showImageOnLoading(defaultPic)// 設定圖片在下載期間顯示的圖片
		 .showImageForEmptyUri(defaultPic)// 設定圖片Uri為空或是錯誤的時候顯示的圖片
		 .showImageOnFail(defaultPic)// 設定圖片載入/解碼過程中錯誤時候顯示的圖片
		 .cacheInMemory(false)// 設定下載的圖片是否快取在記憶體中
		 .cacheOnDisk(cacheOnDisk)// 設定下載的圖片是否快取在SD卡中
		 .considerExifParams(true)//是否考慮JPEG影象EXIF引數（旋轉，翻轉）
		 .displayer(isRound ? new CircleBitmapDisplayer() : new SimpleBitmapDisplayer())//FadeInBitmapDisplayer(200)listview載入閃爍問題
		 .imageScaleType(ImageScaleType.IN_SAMPLE_POWER_OF_2)//圖片將降低2倍，直到下一減少步驟，使影象更小的目標大小
		 .bitmapConfig(Bitmap.Config.RGB_565)//圖片色彩565
		 .build();
		 imageLoader.displayImage(url, iv, options);
	}
 

3、擴充套件，圖片顯示方式，圓角；CircleBitmapDisplayer()

private static class CircleBitmapDisplayer implements BitmapDisplayer {
		    final int margin ;
		    public CircleBitmapDisplayer() {
		        this(0);
		    }
		    public CircleBitmapDisplayer(int margin) {
		        this.margin = margin;
		    }
		    @Override
		    public void display(Bitmap bitmap, ImageAware imageAware, LoadedFrom loadedFrom) {
		        if (!(imageAware instanceof ImageViewAware)) {
		            throw new IllegalArgumentException("ImageAware should wrap ImageView. ImageViewAware is expected.");
		        }
		        imageAware.setImageBitmap(ToRoundBitmap.toRoundBitmap(bitmap));
		    }
	 }
 

4、返回圓形bitmap；toRoundBitmap()

public static  Bitmap toRoundBitmap(Bitmap bitmap) {
		 int width = bitmap.getWidth();
		 int height = bitmap.getHeight();
		 float roundPx;
	     float left,top,right,bottom,dst_left,dst_top,dst_right,dst_bottom;
		 if (width <= height) {
		      roundPx = width / 2;
		      top = 0;
		      left = 0;
		      bottom = width;
	          right = width;
	          height = width;
		      dst_left = 0;
		      dst_top = 0;
		      dst_right = width;
		      dst_bottom = width;
		  } else {
		      roundPx = height / 2;
	          float clip = (width - height) / 2;
		      left = clip;
		      right = width - clip;
		      top = 0;
		      bottom = height;
			  width = height;
			  dst_left = 0;
			  dst_top = 0;
			  dst_right = height;
			  dst_bottom = height;
	     }

	        Bitmap output = Bitmap.createBitmap(width,height, Config.ARGB_8888);
			Canvas canvas = new Canvas(output);
			
		    final int color = 0xff424242;
			final Paint paint = new Paint();
			final Rect src = new Rect((int)left, (int)top, (int)right, (int)bottom);
		    final Rect dst = new Rect((int)dst_left, (int)dst_top, (int)dst_right, (int)dst_bottom);
			final RectF rectF = new RectF(dst);

			paint.setAntiAlias(true);

	        canvas.drawARGB(0, 0, 0, 0);
		    paint.setColor(Color.WHITE);
		    
		    paint.setStrokeWidth(4); 
	        canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
	        paint.setXfermode(new PorterDuffXfermode(Mode.SRC_IN));
		    canvas.drawBitmap(bitmap, src, dst, paint);
		    
	        return output ; 
		}

5、根據圖片uri返回bitmap；此快取位置為記憶體

public static Bitmap getBitmapUtils(String imgUri){
		return imageLoader.getMemoryCache().get(imgUri);
	}

6、根據圖片uri返回File；此快取位置為sd卡

public static File getFileUtils(String imgUri){
		return imageLoader.getDiskCache().get(imgUri);
	}

7、獲取imageloader快取所有圖片總計大小

public static long getCacheFileSize(){
		File disCacheFile = imageLoader.getDiskCache().getDirectory();
		long size = 0;
		for(int i=0; i<disCacheFile.listFiles().length; i++){
			size += disCacheFile.listFiles()[i].length();
		}
		return size;
	}

8、清除圖片快取

public static void clearImageCache(){
		imageLoader.clearDiskCache();//清除磁碟快取
		imageLoader.clearMemoryCache();//清除記憶體快取
	}