public?void?showImageByAsyncTask(ImageView?imageView,?String?url)?{

????//?從緩存中取出對(duì)應(yīng)的圖片

????Bitmap?bitmap?=?getBitmapFromCache(url);

????//?如果緩存中沒(méi)有，那么必須去下載

????if?(bitmap?==?null)?{

????????new?NewsAsyncTask(imageView,?url).execute(url);

????}?else?{

????????imageView.setImageBitmap(bitmap);

????}

}

這里是先從緩存中獲取對(duì)應(yīng)的圖片，所以應(yīng)該將

Bitmap bitmap = getBitmapFromURL(url);
替換為：

Bitmap bitmap = getBitmapFromCache(url);