Android - 从URL添加到rootview的位图

Question

我在从URL中拉取位图时遇到了一些问题。我在Stack上使用了另一个问题的例子，但它不会加载图像。下面是代码：

public class Image extends Activity{ 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 

    Bitmap bitmap = DownloadImage("http://cogadget.com/cogadget/wp-content/uploads/2010/05/Android-Logo-50x50.jpg"); 
    ImageView img = (ImageView) findViewById(R.id.imageView1); 
    img.setImageBitmap(bitmap); 
} 

private InputStream OpenHttpConnection(String urlString) throws IOException { 
    InputStream in = null; 
    int response = -1; 

    URL url = new URL(urlString); 
    URLConnection conn = url.openConnection(); 

    if (!(conn instanceof HttpURLConnection)) 
     throw new IOException("Not an HTTP connection"); 


    try { 
     HttpURLConnection httpConn = (HttpURLConnection) conn; 
     httpConn.setAllowUserInteraction(false); 
     httpConn.setInstanceFollowRedirects(true); 
     httpConn.setRequestMethod("GET"); 
     httpConn.connect(); 
     response = httpConn.getResponseCode(); 
     if (response == HttpURLConnection.HTTP_OK) { 
      in = httpConn.getInputStream(); 
     } 
    } catch (Exception ex) { 
     throw new IOException("Error connecting"); 

    } 
    return in; 
} 

private Bitmap DownloadImage(String URL) { 
    Bitmap bitmap = null; 
    InputStream in = null; 

    try { 
     in = OpenHttpConnection(URL); 
     bitmap = BitmapFactory.decodeStream(in); 
     in.close(); 
    } catch (IOException e1) { 
     // TODO Auto-generated catch block 
     e1.printStackTrace(); 
    } 
    return bitmap; 
} 

}

我试图来用URL位图的ImageView的。我可以在我的模拟器上连接到互联网，但在logcat中它告诉我它无法建立连接。我还在互联网的清单中设置了权限。我被可能是一个简单的修补程序的傻眼了。

Answer 1

您正试图在UI线程上运行网络操作（http连接）。你应该看看线程& asynctasks：http://developer.android.com/guide/components/processes-and-threads.html