绘制常规图形
//绘制圆
addCircle(float x, float y, float radius, Direction dir)
//绘制椭圆
addOval(RectF oval, Direction dir)
addOval(float left, float top, float right, float bottom, Direction dir)
//绘制矩形
addRect(RectF rect, Direction dir)
addRect(float left, float top, float right, float bottom, Direction dir)
//绘制圆角矩形
addRoundRect(RectF rect, float rx, float ry, Direction dir)
addRoundRect(float left, float top, float right, float bottom, float rx, float ry,Direction dir)
addRoundRect(RectF rect, float[] radii, Direction dir)
addRoundRect(float left, float top, float right, float bottom, float[] radii,Direction dir)
所有方法里面都有一个共同的参数Direction ：
Direction 备注
Path.Direction.CCW counter-clockwise ，沿逆时针方向绘制
Path.Direction.CW clockwise ，沿顺时针方向绘制
Direction 用法示例：
//初始化Paint
Paint paint = new Paint();
paint.setColor(Color.RED);
paint.setStyle(Paint.Style.STROKE);
paint.setStrokeWidth(2f);
paint.setTextSize(40f);
//初始化Path
Path path = new Path();
//以（600,600）为圆心，300为半径绘制圆
//Path.Direction.CW顺时针绘制圆 Path.Direction.CCW逆时针绘制圆
path.addCircle(600, 600, 300, Path.Direction.CW);
//沿path绘制文字
canvas.drawTextOnPath("痛苦最好是别人的，快乐才是自己的；麻烦将是暂时的，朋友总是永恒的。", path, 0, 0, paint);
canvas.drawPath(path, paint);
效果图：
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