Android如何解决从错误线程触摸View的问题？

Question

我收到错误“CalledFromWrongThreadException：只有创建视图层次结构的原始线程才能触摸其视图。”

问题来自TutorialThread 中的onDraw 调用。如果调用该代码，则该代码有效 onDraw 中的 startAnimation 被删除。为什么删除 startAnimation 后代码还能工作？ 为什么此调用与对drawRect的调用不同？

下面是代码：

public class GamePanel extends Activity { 私人面板 mPanel；

public void onCreate(Bundle savedInstanceState) {       
    super.onCreate(savedInstanceState);
    mPanel = new Panel(this);
    setContentView(mPanel);
    mPanel.requestFocus(); 
}

}

类Panel 扩展SurfaceView 实现SurfaceHolder.Callback{ 私人教程线程_线程； 私人画图mPaint； 上下文上下文； 私人最终 GamePanel 游戏；

public Panel(Context context) {
    super(context); 
    this.game = (GamePanel) context;
    getHolder().addCallback(this);
    _thread = new TutorialThread(getHolder(),this);

    setFocusable(true);
    mPaint = new Paint();
}  
@Override
public void onDraw(Canvas canvas) {             
    canvas.drawARGB(255, 0, 0, 0);              
    mPaint.setColor(Color.WHITE);
    mPaint.setStyle(Paint.Style.FILL);
    canvas.drawRect(100, 100, 150, 150, mPaint);
    startAnimation(AnimationUtils.loadAnimation(game,R.anim.shake));
}               
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height){

}
@Override
public void surfaceCreated(SurfaceHolder holder){
    _thread.setRunning(true);
    _thread.start();
}
@Override
public void surfaceDestroyed(SurfaceHolder holder){
    boolean retry = true;
    _thread.setRunning(false);
    while(retry) {
        try {
            _thread.join();
            retry = false;
        } catch(InterruptedException e) {

        }
    }
}

class TutorialThread extends Thread {
    private SurfaceHolder _surfaceHolder;
    private Panel _panel;
    private boolean _run = false;

    public TutorialThread(SurfaceHolder surfaceHolder,Panel panel){
        _surfaceHolder = surfaceHolder;
        _panel = panel;
    }
    public void setRunning(boolean run){
        _run = run;
    }
    @Override
    public void run(){
        Canvas c;
        while(_run){
            c=null;
            try{
                c = _surfaceHolder.lockCanvas(null);
                synchronized(_surfaceHolder){                       
                    _panel.onDraw(c);
                }
            }finally{
                if(c!=null){
                    _surfaceHolder.unlockCanvasAndPost(c);
                }
            }
            try
            {
                Thread.sleep(500);
            }
                catch(InterruptedException Ie) {
            }                   
        }           
    }       
}

}

Answer 1

您应该使用 AsyncTask，而不是自定义 Thread 类。 AsyncTask 可以正确且轻松地使用 UI 线程。