android layout圆角,android – 绘制具有圆角的LinearLayout

我试图实现一个LinearLayout子类,它使用圆角绘制自己.从我的研究中,我设置setWillNotDraw(false)并覆盖onDraw()在画布中绘制一个圆角矩形：

@Override

protected void onDraw(Canvas canvas) {

super.onDraw(canvas);

int sc = canvas.saveLayer(0, 0, getWidth(), getHeight(), drawPaint, Canvas.MATRIX_SAVE_FLAG | Canvas.CLIP_SAVE_FLAG | Canvas.HAS_ALPHA_LAYER_SAVE_FLAG

| Canvas.FULL_COLOR_LAYER_SAVE_FLAG | Canvas.CLIP_TO_LAYER_SAVE_FLAG);

canvas.drawRoundRect(bounds, mCornerRadius, mCornerRadius, roundPaint);

canvas.restoreToCount(sc);

}

哪里：

drawPaint = new Paint(Paint.ANTI_ALIAS_FLAG);

drawPaint.setColor(0xffffffff);

drawPaint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.DST_IN));

roundPaint = new Paint(Paint.ANTI_ALIAS_FLAG);

roundPaint.setColor(0xffffffff);

DST_IN在这里是正确的选择(根据APIDemos的例子),但是应该是透明的区域(圆角的)改为黑色背景,孩子的角落仍然可见.这是使用Android 4.2.2的Galaxy Nexus的结果：

任何提示？

编辑：这是我想要实现的,对于拍摄的粗鲁感到遗憾:)

谢谢 😉