Android Path详解

Path内部类

Path.Direction

• Path.Direction.CCW：counter-clockwise的缩写，逆时针创建路径。
• Path.Direction.CW：clockwise的缩写，顺时针创建路径。

Path.FillType

Path.Op

Path的绘制

1.矩形路径

• addRect(float left, float top, float right, float bottom, Path.Direction dir)
• addRect(RectF rect, Path.Direction dir)

Path pathRect1 = new Path();
RectF rectFRect1 = new RectF(50, 200 + paddingTop, 500, 400);
pathRect1.addRect(rectFRect1, Path.Direction.CCW);

mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(5);
canvas.drawPath(pathRect1, mPaint);

2.椭圆路径

• addOval(RectF oval, Path.Direction dir)
• addOval(float left, float top, float right, float bottom, Direction dir)

Path pathOval = new Path();
RectF rectFOval1 = new RectF(50, 600 + paddingTop, 500, 800);
pathOval.addOval(rectFOval1, Path.Direction.CW);

mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(5);
canvas.drawPath(pathOval, mPaint);

3.圆角矩形路径

• addRoundRect(RectF rect, float[] radii, Path.Direction dir)
• addRoundRect(float left, float top, float right, float bottom, float[] radii,Direction dir)
• addRoundRect(RectF rect, float rx, float ry, Path.Direction dir)
• addRoundRect(float left, float top, float right, float bottom, float rx, float ry,Direction dir)

//统一圆角
Path pathRoundRect1 = new Path();
RectF rectFRoundRect = new RectF(50, 1000 + paddingTop, 500, 1200);
pathRoundRect1.addRoundRect(rectFRoundRect,50,50,Path.Direction.CW);
        
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(5);
canvas.drawPath(pathRoundRect1, mPaint);
drawRightDescr(canvas, 1100 + paddingTop, "统一四角,addRoundRect");

//四角自定义
Path pathRoundRect2 = new Path();
RectF rectFRoundRect2 = new RectF(50, 1200 + paddingTop, 500, 1400);
float[] radii={0,0,50,50,0,0,50,50};
pathRoundRect2.addRoundRect(rectFRoundRect2,radii,Path.Direction.CW);

mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(5);
canvas.drawPath(pathRoundRect2, mPaint);

4.圆形路径

• addCircle(float x, float y, float radius, Path.Direction dir)
  • x：圆心点X轴坐标。
  • y：圆心点Y轴坐标。
  • radius：半径。
  • Path.Direction：绘制方向。

Path pathCircle = new Path();
pathCircle.addCircle(250,1700,100,Path.Direction.CW);

mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(5);
canvas.drawPath(pathCircle, mPaint);

5.弧形路径

• addArc(RectF oval, float startAngle, float sweepAngle)

Path pathArc = new Path();
RectF rectFArc = new RectF(50,2000+paddingTop,500,2200);
pathArc.addArc(rectFArc,0,120);

mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(5);
canvas.drawPath(pathArc, mPaint);

6.直线路径

• moveTo(float x, float y)：设置下一个轮廓线的起点为点(x,y)。
• lineTo(float x, float y)：从最后一个点到指定的点(x,y)添加新的一行。如果在此之前没有调用过moveTo()设置起点，则自动将起点设置为(0,0)。
• close()：关闭当前轮廓线。如果当前点不等于轮廓线的第一个点，则自动添加线段。

//不闭合
Path pathLines1 = new Path();
pathLines1.moveTo(250,2400+paddingTop);
pathLines1.lineTo(50,2600);
pathLines1.lineTo(450,2600);

mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(5);
canvas.drawPath(pathLines1,mPaint);

//闭合
Path pathLines2 = new Path();
pathLines2.moveTo(250,2600+paddingTop);
pathLines2.lineTo(50,2800);
pathLines2.lineTo(450,2800);
pathLines2.close();

mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(5);
canvas.drawPath(pathLines2,mPaint);

//五角星闭合
Path pathLines3 = new Path();
pathLines3.moveTo(250,2800+paddingTop);
pathLines3.lineTo(100,3000);
pathLines3.lineTo(400,2900);
pathLines3.lineTo(100,2900);
pathLines3.lineTo(100,2900);
pathLines3.lineTo(400,3000);
pathLines3.close();

mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeWidth(5);
canvas.drawPath(pathLines3,mPaint);        

作者：Brainbg(白雨)
GitHub：https://github.com/Brainbg
博客：https://www.brainbg.com/
简书：https://www.jianshu.com/u/94518ede7100
CSDN：https://blog.csdn.net/u014720022