canvas.drawRoundRect方法，绘制圆角矩形

public void drawRoundRect (RectF rect, float rx, float ry, Paint paint) Draw the specified round-rect using the specified paint. The roundrect will be filled or framed based on the Style in the paint. Parameters rectThe rectangular bounds of the roundRect to be drawn rxThe x-radius of the oval used to round the corners ryThe y-radius of the oval used to round the corners paintThe paint used to draw the roundRect 【功能说明】该方法用于在画布上绘制圆角矩形，经过指定RectF对象以及圆角半径来实现。该方法是绘制圆角矩形的主要方法，同时也能够经过设置画笔的空心效果来绘制空心的圆角矩形。 【基本语法】public void drawRoundRect (RectF rect, float rx, float ry, Paint paint) 参数说明 rect：RectF对象。 rx：x方向上的圆角半径。 ry：y方向上的圆角半径。 paint：绘制时所使用的画笔。 protected void onDraw(Canvas canvas) {// TODO Auto-generated method stubsuper.onDraw(canvas);//新建一只画笔，并设置为绿色属性Paint _paint = new Paint();_paint.setColor(Color.GREEN);//新建矩形r1RectF r1 = new RectF();r1.left = 50;r1.right = 250;r1.top = 50 ;r1.bottom = 150;//新建矩形r2RectF r2 = new RectF();r2.left = 50;r2.right = 250;r2.top = 200 ;r2.bottom = 300;//画出矩形r1canvas.drawRect(r1, _paint);//画出圆角矩形r2_paint.setColor(Color.rgb(204, 204, 204));canvas.drawRoundRect(r2, 10, 10, _paint);}