试图清除后的And​​r​​oid SurfaceView /帆布闪烁 [英] Android SurfaceView/Canvas flickering after trying to clear it

问题描述

所以，我想明确使用canvas.drawColor（Color.BLACK）画布，但如果我只是把这种一次，显示屏闪烁，显示旧图纸应已涵盖了由drawColor。

So I am trying to clear the Canvas using canvas.drawColor(Color.BLACK) but if I just call this once, the display flickers and displays the old drawing which should have been covered up by the drawColor.

下面是我的code中的重要位 -

Here is the important bits of my code -

    public void update() {


    //This method is called by a Thread                


    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;
}

围绕豆蔻谷歌搜索后，我听说了双缓冲，但来到这lockCanvas（）和unlockCanvasAndPost（）应该处理这对我的理解。这是怎么回事错在这里？

After Googling around a litte, I heard about double buffering but came to the understanding that lockCanvas() and unlockCanvasAndPost() should handle this for me. What is going wrong here?

推荐答案

我不知道这是做 SurfaceView 被双缓冲，他们轮流每一帧。因此，你将不得不清除屏幕至少两帧。

I wonder if this is to do with SurfaceView being double buffered and they alternate each frame. Hence you would have to clear the screen at least two frames.

修改 toClear = TRUE 到 toClear = 2 ，设置

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

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