如何实现多边形按钮、View超出部分没有点击效果

正多边形，超出部分不显示，且没有点击效果

以UIButton为例。创建一个类继承UIButton，给一个外部的属性shapePath。当给shapePath赋值的时候

创建CAShapeLayer，作为遮掩图层。

hitTest:withEvent: 在这个方法里面进行判断点击的点是否在显示的区域内，实现超出部分点击不到。

.h文件

#import@interface ShapeButton : UIButton

@property(nonatomic , strong)UIBezierPath *shapePath;

@end

#import "ShapeButton.h"

@implementation ShapeButton

{

CAShapeLayer *shapeLayer;

}

-(void)setShapePath:(UIBezierPath *)shapePath{

_shapePath=shapePath;

if (_shapePath==nil) {

self.layer.mask=nil;

return;

}

if (!shapeLayer) {

shapeLayer=[CAShapeLayer layer];

}

shapeLayer.path=_shapePath.CGPath;

self.layer.mask=shapeLayer;

}

-(UIView *)hitTest:(CGPoint)point withEvent:(UIEvent *)event{

if (_shapePath&&[_shapePath containsPoint:point]==NO) {

return nil;

}

return [super hitTest:point withEvent:event];

}

@end

2.如何绘制正多边形

-(UIBezierPath *)width:(CGFloat )width center:(CGPoint)center lineCount:(NSInteger)count{

UIBezierPath *auxiliaryPath=[UIBezierPath bezierPath];

UIBezierPath *path=[UIBezierPath bezierPath];

[auxiliaryPath moveToPoint:CGPointMake(center.x+width, center.y)];

[path moveToPoint:auxiliaryPath.currentPoint];

for (int i=0; i

[auxiliaryPath addArcWithCenter:center radius:width startAngle:2*M_PI/(count*1.0)*i endAngle:2*M_PI/(count*1.0)*(i+1) clockwise:YES];

[path addLineToPoint:auxiliaryPath.currentPoint];

}

return path;

}

在VC中调用

（当然也可以半圆等其他形状的UIBezierPath）