Question

当我创建一个使用View创建基本动画的应用程序时，使用无效的循环它会一次又一次地给出连续动画。但是，在使用SurfaceView时，使用invalidate会产生错误。有人能帮帮我吗？

package com.example.newapplication;

import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

public class SurfaceAnimation extends SurfaceView implements Runnable{


    SurfaceHolder ourHolder;
    Thread ourThread = null;
    boolean isRunning = true;

    public SurfaceAnimation(Context context) {
        super(context);
        // TODO Auto-generated constructor stub
        ourHolder = getHolder();
        ourThread = new Thread(this);
        ourThread.start();

    }

    @Override
    public void run() {
        // TODO Auto-generated method stub
        while(isRunning){
            if(!ourHolder.getSurface().isValid())
                continue;
            else{
                Canvas canvas = ourHolder.lockCanvas();
                canvas.drawColor(Color.CYAN);
                ourHolder.unlockCanvasAndPost(canvas);
//              invalidate();
                }

        }


    } 

}

上面的logcat是：

05-30 04:41:47.240: E/AndroidRuntime(1869): FATAL EXCEPTION: Thread-120
05-30 04:41:47.240: E/AndroidRuntime(1869): Process: com.example.newapplication, PID: 1869
05-30 04:41:47.240: E/AndroidRuntime(1869): android.view.ViewRootImpl$CalledFromWrongThreadException: Only the original thread that created a view hierarchy can touch its views.
05-30 04:41:47.240: E/AndroidRuntime(1869):     at android.view.ViewRootImpl.checkThread(ViewRootImpl.java:6094)
05-30 04:41:47.240: E/AndroidRuntime(1869):     at android.view.ViewRootImpl.invalidateChildInParent(ViewRootImpl.java:857)
05-30 04:41:47.240: E/AndroidRuntime(1869):     at android.view.ViewGroup.invalidateChild(ViewGroup.java:4320)
05-30 04:41:47.240: E/AndroidRuntime(1869):     at android.view.View.invalidate(View.java:10935)
05-30 04:41:47.240: E/AndroidRuntime(1869):     at android.view.View.invalidate(View.java:10890)
05-30 04:41:47.240: E/AndroidRuntime(1869):     at com.example.newapplication.SurfaceAnimation.run(SurfaceAnimation.java:35)
05-30 04:41:47.240: E/AndroidRuntime(1869):     at java.lang.Thread.run(Thread.java:841)

Answer 1

如果要从非ui线程更新视图，则必须使用postInvalidate()而不是invalidate()。这就是你的logcat所说的：

只有创建视图层次结构的原始线程才能触及它视图。

Answer 2

不要调用invalidate（），而是调用postInvalidate（）;

在创建动画时使用View时使用invalidate（）

2 个答案: