ios 扩大button的点击区域

.h定义我们设置的最小响应区域大小
/**
 *  事件响应最小区域大小(小于此区域则放大，否则保持原大小不变，不赋值保持原大小不变)
 */
@property (nonatomic, assign) CGSize eventFrame;
.m重写pointInside方法
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent*)event{
    
CGRect bounds = self.bounds;
CGFloat widthExtra = MAX(self.eventFrame.width - bounds.size.width, 0);
CGFloat heightExtra = MAX(self.eventFrame.height - bounds.size.height, 0);
bounds = CGRectInset(bounds, -0.5 * widthExtra, -0.5 * heightExtra);
return CGRectContainsPoint(bounds, point);
}