Android-清除Canvs內容的實現

標籤：android   style   class   blog   code   color   

SurfaceView背景透明：

setZOrderOnTop(true);
SurfaceHolder holder = this.getHolder();holder.setFormat(PixelFormat.TRANSLUCENT);

清除Canvas內容的實現方式一：

Canvas canvas = null;try {　　synchronized (holder) {　　　　canvas = holder.lockCanvas(null);　　　　if (canvas == null) {　　　　　　return;　　　　}　　　　canvas.drawColor(Color.TRANSPARENT, PorterDuff.Mode.CLEAR); 　　}} catch (Exception e) {　　e.printStackTrace();} finally {　　if (canvas != null) {　　　　holder.unlockCanvasAndPost(canvas);　　}}

方式二：

 Paint paint = new Paint();   paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.CLEAR));   canvas.drawPaint(paint);   paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC));