尝试清除Android SurfaceView / Canvas后闪烁

Question

因此，我尝试使用canvas.drawColor（Color.BLACK）清除Canvas，但如果仅调用一次，则显示闪烁并显示应该由drawColor覆盖的旧图形。

这是我代码的重要部分-

// This method is called by a Thread                
public void update() {
    Canvas canvas = holder.lockCanvas(null);
    if (canvas != null) {
        onDraw(canvas);
    }
    holder.unlockCanvasAndPost(canvas);
}

@Override
protected void onDraw(Canvas canvas) {

    if (toClear) {
        canvas.drawColor(Color.BLACK);

        //if this is not set to change back to false, it does not flicker
        toClear = false;
    }

    //Draw some objects that are moving around
}

public void clearScreen() {     
    // This method is called when the user pressed a button
    toClear = true;
}

在Google搜索一个小贴士之后，我听说了双重缓冲，但是我了解到lockCanvas（）和unlockCanvasAndPost（）应该为我处理这个问题。这是怎么了？

Answer 1

我想知道这是否与SurfaceView双缓冲有关，并且它们交替每帧。因此，您必须至少清除屏幕两帧。

更改toClear = true成toClear = 2与集

if(toClear > 0) { 
   'drawColor'
   toClear--; 
}