UIButton设置按钮点击范围大于可视范围

自定义按钮类型CustomButton，继承UIButton，重写pointInside函数改变点击响应范围。

例如，按钮点击范围比实际高度上下增加6。

CustomButton.h

@interface CustomButton : UIButton
@end

CustomButton.m

#import "CustomButton.h"
CGFloat const ButtonInset = .f;
@implementation CustomButton
- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event
{
    CGRect newArea = CGRectMake(self.bounds.origin.x, self.bounds.origin.y - ButtonInset, self.bounds.size.width, self.bounds.size.height + ButtonInset * ); return CGRectContainsPoint(newArea, point);
}
@end