Android ApiDemos示范解析(73):Graphics->Points
Android ApiDemos示例解析(73):Graphics->Points
本例对应的例子为DrawPoints.java,介绍如何使用Canvas来绘制点。
Canvas 提供3个重载函数来绘制点(单个点或是一组点)
- public void drawPoint(float x, float y, Paint paint)
- public void drawPoints(float[] pts, Paint paint)
- public void drawPoints(float[] pts, int offset, int count, Paint paint)
绘制点的中心由点的坐标给定,点的宽度由Paint的Stroke宽度指定(并受当前Canvas的Matrix影响)。stroke width为0比较特殊,点的宽度总为1个像素(打开Antialiasing支持时为4个像素)。
本例绘制一组点和由点连接的直线:
Paint paint = mPaint; canvas.translate(10, 10); canvas.drawColor(Color.WHITE); paint.setColor(Color.RED); paint.setStrokeWidth(0); canvas.drawLines(mPts, paint); paint.setColor(Color.BLUE); paint.setStrokeWidth(3); canvas.drawPoints(mPts, paint);