增大UIButton的点击热区

有两种方法可以处理这个问题：

1.视图中

    UIButton * button = [UIButton buttonWithType:UIButtonTypeCustom];

    button.frame = CGRectMake(100, 100, 20, 20);

    button.backgroundColor = [UIColor yellowColor];

    [button addTarget:self action:@selector(testButtonAction:) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:button];

    button.minHitTestWidth = 180;// 点击区域宽高

    button.minHitTestHeight = 180;

2.搭配类别使用

.h 文件

#import <UIKit/UIKit.h>

@interface UIButton (HitAreaExpand)

@property (nonatomic) CGFloat minHitTestWidth;

@property (nonatomic) CGFloat minHitTestHeight;

@end

.m 文件

#import "UIButton+HitAreaExpand.h"

#import <objc/runtime.h>

@implementation UIButton (HitAreaExpand)

- (CGFloat)minHitTestWidth {

    NSNumber * width = objc_getAssociatedObject(self, @selector(minHitTestWidth));

    return [width floatValue];

}

- (void)setMinHitTestWidth:(CGFloat)minHitTestWidth {

    objc_setAssociatedObject(self, @selector(minHitTestWidth), [NSNumber numberWithFloat:minHitTestWidth], OBJC_ASSOCIATION_ASSIGN);

}

- (CGFloat)minHitTestHeight {

    NSNumber * height = objc_getAssociatedObject(self, @selector(minHitTestHeight));

    return [height floatValue];

}

- (void)setMinHitTestHeight:(CGFloat)minHitTestHeight {

    objc_setAssociatedObject(self, @selector(minHitTestHeight), [NSNumber numberWithFloat:minHitTestHeight], OBJC_ASSOCIATION_ASSIGN);

}

- (BOOL)pointInside:(CGPoint)point withEvent:(nullable UIEvent *)event {

    return CGRectContainsPoint(HitTestingBounds(self.bounds, self.minHitTestWidth, self.minHitTestHeight), point);

}

CGRect HitTestingBounds(CGRect bounds, CGFloat minimumHitTestWidth, CGFloat minimumHitTestHeight) {

    CGRect hitTestingBounds = bounds;

    if (minimumHitTestWidth > bounds.size.width) {

        hitTestingBounds.size.width = minimumHitTestWidth;

        hitTestingBounds.origin.x -= (hitTestingBounds.size.width - bounds.size.width)/2;

    }

    if (minimumHitTestHeight > bounds.size.height) {

        hitTestingBounds.size.height = minimumHitTestHeight;

        hitTestingBounds.origin.y -= (hitTestingBounds.size.height - bounds.size.height)/2;

    }

    return hitTestingBounds;

}

@end