Android 后台线程弹对话框导致程序崩溃(is not valid; is your activity running)

异常：android.view.WindowManager$BadTokenException: Unable to add window — token android.os.BinderProxy@438e7108 is not valid; is your activity running?

 

 

因为使用了AsyncTask 异步线程在线程完成以后的onPostExecute方法里面弹出窗口。

这个时候如果用户在onPostExecute调用之间按了返回按钮,activity已经onDestory了，
那么就会报出android.view.WindowManager$BadTokenException: Unable to add window -- token android.os.BinderProxy@4479b390 is not valid; is your activity running?

解决方法一在弹出窗口之前用Activity的isFinishing判断一下Activity是否还存在:

protected void onPostExecute(Object result) {   
    if (!isFinishing()) {   
        showDialog(MY_DIALOG_ID);   
    }   
}  

解决方法二在show的时候捕获一下异常


以下是测试验证
运行这个小程序 默数4的时候按返回 如果不加异常捕获或者判断isFinish的话会崩溃。 

public class DialogTestActivity extends Activity {   
    @Override  
    public void onCreate(Bundle savedInstanceState) {   
        super.onCreate(savedInstanceState);   
        setContentView(R.layout.main);   
        new Task().execute();   
  
    }   
  
    private class Task extends AsyncTask {   
  
        @Override  
        protected Void doInBackground(Void... params) {   
            try {   
                Thread.sleep(5000);   
            } catch (InterruptedException e) {   
                e.printStackTrace();   
            }   
            return null;   
        }   
  
        @Override  
        protected void onPostExecute(Void result) {   
            super.onPostExecute(result);   
            //if (!isFinishing()) {   
                //try {   
                    createAlertDialog().show();   
                //} catch (Exception e) {   
                //}   
            //}   
        }   
  
    }   
  
    private AlertDialog createAlertDialog() {   
        return new AlertDialog.Builder(DialogTestActivity.this).setTitle("fadfasdf")   
                .setPositiveButton("OK", new DialogInterface.OnClickListener() {   
                    public void onClick(DialogInterface dialog, int whichButton) {   
  
                    }   
                }).setNegativeButton("Cancel", new DialogInterface.OnClickListener() {   
                    public void onClick(DialogInterface dialog, int whichButton) {   
  
                    }   
                }).create();   
    }   
}  

 

转自:http://dingbuoyi.iteye.com/blog/1555030#comments

更多:http://dimitar.me/android-displaying-dialogs-from-background-threads/