【Android】Canvas 清畫面

清空繪圖板畫面在各網站已有解法, 像是

Paint paint = new Paint();
paint.setXfermode(new PorterDuffXfermode(Mode.CLEAR));
canvas.drawPaint(paint);
paint.setXfermode(new PorterDuffXfermode(Mode.SRC));
// start your own drawing

或是這個網站也有解法 http://blog.csdn.net/yanzi1225627/article/details/8236309


然而,今天遇到奇怪現像, 造成清不乾淨, 這可能是我繪圖方法沒寫好, 只好多清空2次, 無言...


java code 如下(繪圖元件還是不熟)


            for(int i = 0; i < 4; i++) {
                clearDraw();
            }


    // 清除畫面
    private void clearDraw() {

        Canvas canvas = surHolder.lockCanvas();
        canvas.drawColor(Color.TRANSPARENT);
//
        Paint p = new Paint();
        //清屏
        p.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));
        canvas.drawPaint(p);

        mCanvas.drawPaint(p);

        surHolder.unlockCanvasAndPost(canvas);
    }