从 getView 内的线程内更新视图?

Update a view from within a thread inside getView?

我有一个 activity class 调用我的自定义适配器 class 来扩展基本适配器。在我的 getView 方法中,我有一个 button.setOnClickListener,其中有一个线程可以下载数据。我想在用户点击时将按钮文本设置为"downloading",然后在下载完成后,将按钮文本设置为"finished"。我该怎么做?

public class MyActivity extends Activity {
//some code here
private void setAdapter(ArrayList arrayList) {      
    listView.setAdapter(new UserAdapter(context,arrayList));        
}
}


public class UserAdapter extends BaseAdapter {

@Override
public View getView(int position, View convertView, ViewGroup parent) {     
     Holder holder = new Holder();      
     holder.button = (Button) view.findViewById(R.id.button);
     holder.button.setOnClickListener(new View.OnClickListener() {
     @Override
     public void onClick(View v) {
        new Thread(new Runnable() {
            @Override
            public void run() {

                try{
                  //set button text to "downloading"
                  //establish an http connection and download data
                  //after download done, if successfull set button text to downloaded
                  //if download failed, set button text to failed.
                } catch (Exception exception) {
                }
            }
            }
        ).start();
      }
    });

    return view;
}
private class Holder {
    private Button button;
}
}

为了更新线程内的视图,请像这样在 getView 方法内使用 runOnUithread。在 activity 中你可以直接使用,但在 activity 之外你必须使用上下文。

context.runOnUiThread(new Runnable(){
    public void run() {
        //If there are stories, add them to the table

      try{
           }
        } catch (final Exception ex) {
            Log.i("---","Exception in thread");
        }
    }
});

对于 http 请求,您可以使用 asyncTask。