适用于任何容器中的imageView，比如listview grid view, normal layout

 private class LoadImagefromUrl extends AsyncTask< Object, Void, Bitmap > {
        ImageView ivPreview = null;

        @Override
        protected Bitmap doInBackground( Object... params ) {
            this.ivPreview = (ImageView) params[0];
            String url = (String) params[1];
            System.out.println(url);
            return loadBitmap( url );
        }

        @Override
        protected void onPostExecute( Bitmap result ) {
            super.onPostExecute( result );
            ivPreview.setImageBitmap( result );
        }
    }

    public Bitmap loadBitmap( String url ) {
        URL newurl = null;
        Bitmap bitmap = null;
        try {
            newurl = new URL( url );
            bitmap = BitmapFactory.decodeStream( newurl.openConnection( ).getInputStream( ) );
        } catch ( MalformedURLException e ) {
            e.printStackTrace( );
        } catch ( IOException e ) {

            e.printStackTrace( );
        }
        return bitmap;
    }
/** Usage **/
  new LoadImagefromUrl( ).execute( imageView, url );

这段代码经过测试，它是完全工作的。

URL req = new URL(
"http://java.sogeti.nl/JavaBlog/wp-content/uploads/2009/04/android_icon_256.png"
);
Bitmap mIcon_val = BitmapFactory.decodeStream(req.openConnection()
                  .getInputStream());

不管怎样，人们问我的评论，把它作为答案。我正在发帖。

URL newurl = new URL(photo_url_str); 
mIcon_val = BitmapFactory.decodeStream(newurl.openConnection().getInputStream());
profile_photo.setImageBitmap(mIcon_val);

我写了一个类来处理这个问题，因为它似乎是我各种项目中反复出现的需求:

https://github.com/koush/UrlImageViewHelper

UrlImageViewHelper will fill an ImageView with an image that is found at a URL. The sample will do a Google Image Search and load/show the results asynchronously. UrlImageViewHelper will automatically download, save, and cache all the image urls the BitmapDrawables. Duplicate urls will not be loaded into memory twice. Bitmap memory is managed by using a weak reference hash table, so as soon as the image is no longer used by you, it will be garbage collected automatically.

我最近在这里找到了一个线程，因为我必须为带有图像的列表视图做类似的事情，但原理很简单，正如您可以在那里显示的第一个示例类中读到的那样(由jleedev)。 你得到图像的输入流(从网络)

private InputStream fetch(String urlString) throws MalformedURLException, IOException {
    DefaultHttpClient httpClient = new DefaultHttpClient();
    HttpGet request = new HttpGet(urlString);
    HttpResponse response = httpClient.execute(request);
    return response.getEntity().getContent();
}

然后你将图像存储为可绘制的，你可以将它传递给ImageView(通过setImageDrawable)。同样从上面的代码片段来看一下整个线程。

InputStream is = fetch(urlString);
Drawable drawable = Drawable.createFromStream(is, "src");

来自Android开发者:

// show The Image in a ImageView
new DownloadImageTask((ImageView) findViewById(R.id.imageView1))
            .execute("http://java.sogeti.nl/JavaBlog/wp-content/uploads/2009/04/android_icon_256.png");

public void onClick(View v) {
    startActivity(new Intent(this, IndexActivity.class));
    finish();

}

private class DownloadImageTask extends AsyncTask<String, Void, Bitmap> {
    ImageView bmImage;

    public DownloadImageTask(ImageView bmImage) {
        this.bmImage = bmImage;
    }

    protected Bitmap doInBackground(String... urls) {
        String urldisplay = urls[0];
        Bitmap mIcon11 = null;
        try {
            InputStream in = new java.net.URL(urldisplay).openStream();
            mIcon11 = BitmapFactory.decodeStream(in);
        } catch (Exception e) {
            Log.e("Error", e.getMessage());
            e.printStackTrace();
        }
        return mIcon11;
    }

    protected void onPostExecute(Bitmap result) {
        bmImage.setImageBitmap(result);
    }
}

确保你在AndroidManifest.xml中设置了以下权限来访问互联网。

<uses-permission android:name="android.permission.INTERNET" />