有没有其他方式来显示url图像？

public class ImageDownloader extends AsyncTask { Context context; ImageView image; public ImageDownloader(ImageView image) { this.image = image; } protected void onPreExecute() { } protected Drawable doInBackground(String... urls) { InputStream is; Drawable d = null ; try { is = (InputStream)new URL(urls[0]).getContent(); d = Drawable.createFromStream(is, "Image"); return d; } catch (MalformedURLException e) { // TODO Auto-generated catch block e.printStackTrace(); } catch (IOException e) { // TODO Auto-generated catch block e.printStackTrace(); } return d; } protected void onPostExecute(Drawable d) { if(d != null){ d.setBounds(0, 0, d.getIntrinsicWidth(), d.getIntrinsicHeight()); image.setBackgroundDrawable(d); }else{ image.setBackgroundDrawable(context.getResources().getDrawable(R.drawable.noimage)); Toast.makeText(context, "No image", Toast.LENGTH_LONG).show(); } } 

}

因为它在开始时工作，但是当我下载大量图像时它会崩溃。 我查看了我的LogCat，这是因为没有更多的分配。 我想做一个像Pulse News这样的应用程序，它可以显示图像但不会每次都崩溃。 我是冰淇淋三明治，以防万一。

Answer 1

您需要了解java中的SoftReference类。 来吧，搜索它。你会得到你的答案

Answer 2

我发现这个课程，它工作正常，非常好！

 public class LoaderImageView extends LinearLayout{ private static final int COMPLETE = 0; private static final int FAILED = 1; private Context mContext; private Drawable mDrawable; private ProgressBar mSpinner; private ImageView mImage; /** * This is used when creating the view in XML * To have an image load in XML use the tag 'image="http://sofzh.miximages.com/java/dialog_buttons.png"' * Replacing the url with your desired image * Once you have instantiated the XML view you can call * setImageDrawable(url) to change the image * @param context * @param attrSet */ public LoaderImageView(final Context context, final AttributeSet attrSet) { super(context, attrSet); final String url = attrSet.getAttributeValue(null, "image"); if(url != null){ instantiate(context, url); } else { instantiate(context, null); } } /** * This is used when creating the view programatically * Once you have instantiated the view you can call * setImageDrawable(url) to change the image * @param context the Activity context * @param imageUrl the Image URL you wish to load */ public LoaderImageView(final Context context, final String imageUrl) { super(context); instantiate(context, imageUrl); } /** * First time loading of the LoaderImageView * Sets up the LayoutParams of the view, you can change these to * get the required effects you want */ private void instantiate(final Context context, final String imageUrl) { mContext = context; mImage = new ImageView(mContext); mImage.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)); mSpinner = new ProgressBar(mContext); mSpinner.setLayoutParams(new LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT)); mSpinner.setIndeterminate(true); addView(mSpinner); addView(mImage); if(imageUrl != null){ setImageDrawable(imageUrl); } } /** * Set's the view's drawable, this uses the internet to retrieve the image * don't forget to add the correct permissions to your manifest * @param imageUrl the url of the image you wish to load */ public void setImageDrawable(final String imageUrl) { mDrawable = null; mSpinner.setVisibility(View.VISIBLE); mImage.setVisibility(View.GONE); new Thread(){ public void run() { try { mDrawable = getDrawableFromUrl(imageUrl); imageLoadedHandler.sendEmptyMessage(COMPLETE); } catch (MalformedURLException e) { imageLoadedHandler.sendEmptyMessage(FAILED); } catch (IOException e) { imageLoadedHandler.sendEmptyMessage(FAILED); } }; }.start(); } /** * Callback that is received once the image has been downloaded */ Handler.Callback call = new Handler.Callback() { public boolean handleMessage(Message msg) { switch (msg.what) { case COMPLETE: mImage.setImageDrawable(mDrawable); mImage.setVisibility(View.VISIBLE); mSpinner.setVisibility(View.GONE); break; case FAILED: default: // Could change image here to a 'failed' image // otherwise will just keep on spinning break; } return true; } }; private final Handler imageLoadedHandler =new Handler(call); /** * Pass in an image url to get a drawable object * @return a drawable object * @throws IOException * @throws MalformedURLException */ private static Drawable getDrawableFromUrl(final String url) throws IOException, MalformedURLException { return Drawable.createFromStream(((java.io.InputStream)new java.net.URL(url).getContent()), "name"); } } 

要使用它，它很简单：

  LoderImageView image = (LoaderImageView) findViewById(R.id.myid); image.setImageDrawable(url);