无法在android中的线程内创建处理程序

如何解决无法在android中的线程内创建处理程序

我正在尝试在if条件下显示警报对话框。

ObdGatewayService.java

 public class ObdGatewayService{

 if(e.getMessage().equals("broken pipe")){
            ((MainActivity) ctx).OBDreconnect();
            }
 } 

MainActivity.java

   public void OBDreconnect() {
    if(!show_obd_reconnect_dialog) {
        AlertDialog.Builder build = new AlertDialog.Builder(this);
        build.setMessage(R.string.obd_losted)
                .setCancelable(false)
                .setPositiveButton("Reconnect",new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog,int id) {
                        startLiveData();
                    }
                })
                .setNegativeButton("Exit",int id) {
                        finish();
                    }
                });
        show_obd_reconnect_dialog = true;
        build.show();
    }
}

在下面出现错误：

 java.lang.RuntimeException: Can't create handler inside thread that has not called Looper.prepare()

解决方法

  if(e.getMessage().equals("Broken pipe")){
                Handler handler = new Handler(Looper.getMainLooper());
                handler.postDelayed(new Runnable() {
                    @Override
                    public void run() {
                        ((MainActivity) ctx).OBDreconnect();

                    }
                },0 );
            }