（1）画虚线

CAShapeLayer *shapeLayer = [CAShapeLayer layer];

[shapeLayer setBounds:self.bounds];

[shapeLayer setPosition:self.center];

[shapeLayer setFillColor:[[UIColor clearColor] CGColor]];

// 设置虚线颜色为blackColor

[shapeLayer setStrokeColor:[[UIColor blackColor] CGColor]];

[shapeLayer setStrokeColor:[[UIColor colorWithRed:223/255.0 green:223/255.0 blue:223/255.0 alpha:1.0f] CGColor]];

// 3.0f设置虚线的宽度

[shapeLayer setLineWidth:1.0f];

[shapeLayer setLineJoin:kCALineJoinRound];

// 3=线的宽度 1=每条线的间距

[shapeLayer setLineDashPattern:

[NSArray arrayWithObjects:[NSNumber numberWithInt:3],

[NSNumber numberWithInt:1],nil]];

// Setup the path

CGMutablePathRef path = CGPathCreateMutable();

CGPathMoveToPoint(path, NULL, 0, 89);

CGPathAddLineToPoint(path, NULL, 320,89);

// Setup the path

CGMutablePathRef path = CGPathCreateMutable();

// 0,10代表初始坐标的x，y

// 320,10代表初始坐标的x，y

CGPathMoveToPoint(path, NULL, 0, 10);

CGPathAddLineToPoint(path, NULL, 320,10);

[shapeLayer setPath:path];

CGPathRelease(path);

// 可以把self改成任何你想要的UIView, 下图演示就是放到UITableViewCell中的

[[self layer] addSublayer:shapeLayer];

（2）画圆

CAShapeLayer *line = [CAShapeLayer layer];

line.lineWidth = 2.0f ;

line.strokeColor = [UIColor orangeColor].CGColor;

line.fillColor = [UIColor clearColor].CGColor;

CGMutablePathRef path = CGPathCreateMutable();

CGPathAddEllipseInRect(path, nil, CGRectMake(100.0f, 100.0f,50.0f, 50.0f));

line.path = path;

CGPathRelease(path);

[self.layer addSublayer:line];