Android 将网络的Url资源转换为Drawable资源方式

private Drawable loadImageFromNetwork(String imageUrl) {
 Drawable drawable = null;
 try {
  drawable = Drawable.createFromStream(
    new URL(imageUrl).openStream(), "image.jpg");
 } catch (IOException e) {
  Log.d("test", e.getMessage());
 }
 if (drawable == null) {
  Log.d("test", "null drawable");
 } else {
  Log.d("test", "not null drawable");
 }
 return drawable;
}

mImageView = (ImageView)this.findViewById(R.id.imageThreadConcept) ; 
Drawable drawable = loadImageFromNetwork(IMAGE_URL); 
mImageView.setImageDrawable(drawable) ; 

private Drawable loadImageFromNetwork(String imageUrl) 
{ 
 Drawable drawable = null; 
 try { 
  // 可以在这里通过文件名来判断，是否本地有此图片 
  drawable = Drawable.createFromStream( 
    new URL(imageUrl).openStream(), "image.jpg"); 
 } catch (IOException e) { 
  Log.d("test", e.getMessage()); 
 } 
 if (drawable == null) { 
  Log.d("test", "null drawable"); 
 } else { 
  Log.d("test", "not null drawable"); 
 } 
  
 return drawable ; 
} 

mImageView = (ImageView)this.findViewById(R.id.imageThreadConcept) ; 
new Thread(new Runnable(){ 
 Drawable drawable = loadImageFromNetwork(IMAGE_URL); 
 @Override 
 public void run() { 
   
  // post() 特别关键，就是到UI主线程去更新图片     
  mImageView.post(new Runnable(){ 
  @Override 
  public void run() { 
   // TODO Auto-generated method stub 
   mImageView.setImageDrawable(drawable) ; 
  }}) ; 
  } 
   
}).start() ; 

mImageView = (ImageView)this.findViewById(R.id.imageThreadConcept) ; 
new DownloadImageTask().execute(IMAGE_URL) ; 
private class DownloadImageTask extends AsyncTask<String, Void, Drawable> 
{ 
   
  protected Drawable doInBackground(String... urls) { 
   return loadImageFromNetwork(urls[0]); 
  } 
 
  protected void onPostExecute(Drawable result) { 
   mImageView.setImageDrawable(result); 
  } 
}