扩大按钮点击区域

思路：建一个UIbutton分类，结合runtime更改按钮点击响应区域

实现代码：

.h

//
//  UIButton+JhLargeTouchArea.h
//  FaceChat
//
//  Created by Administrator on 2018/8/1.
//  Copyright © 2018年 Zanxiang. All rights reserved.
//

#import <UIKit/UIKit.h>

@interface UIButton (JhLargeTouchArea)
/**
 点击区域分别向各个方向扩展的长度

 @param top 上--长度
 @param left 左--长度
 @param bottom 下--长度
 @param right 右--长度
 */
- (void)setJhLargeEdgeWithTop:(CGFloat)top left:(CGFloat)left bottom:(CGFloat)bottom right:(CGFloat)right;
/**
 点击区域分别向四周扩展的长度

 @param size 长度
 */
- (void)setJhLargeEdge:(CGFloat)size;
@end
.m

//

//  UIButton+JhLargeTouchArea.m

//  FaceChat

//

//  Created by Administrator on 2018/8/1.

//  Copyright © 2018年 Zanxiang. All rights reserved.

//

#import "UIButton+JhLargeTouchArea.h"

#import <objc/objc.h>

@implementation UIButton (JhLargeTouchArea)

static char topNameKey;

static char leftNameKey;

static char bottomNameKey;

static char rightNameKey;

- (void)setJhLargeEdgeWithTop:(CGFloat)top left:(CGFloat)left bottom:(CGFloat)bottom right:(CGFloat)right{

    objc_setAssociatedObject(self, &topNameKey, [NSNumber numberWithFloat:top], OBJC_ASSOCIATION_COPY_NONATOMIC);

    objc_setAssociatedObject(self, &leftNameKey, [NSNumber numberWithFloat:left], OBJC_ASSOCIATION_COPY_NONATOMIC);

    objc_setAssociatedObject(self, &bottomNameKey, [NSNumber numberWithFloat:bottom], OBJC_ASSOCIATION_COPY_NONATOMIC);

    objc_setAssociatedObject(self, &rightNameKey, [NSNumber numberWithFloat:right], OBJC_ASSOCIATION_COPY_NONATOMIC);

}

- (void)setJhLargeEdge:(CGFloat)size{

    objc_setAssociatedObject(self, &topNameKey, [NSNumber numberWithFloat:size], OBJC_ASSOCIATION_COPY_NONATOMIC);

    objc_setAssociatedObject(self, &leftNameKey, [NSNumber numberWithFloat:size], OBJC_ASSOCIATION_COPY_NONATOMIC);

    objc_setAssociatedObject(self, &bottomNameKey, [NSNumber numberWithFloat:size], OBJC_ASSOCIATION_COPY_NONATOMIC);

    objc_setAssociatedObject(self, &rightNameKey, [NSNumber numberWithFloat:size], OBJC_ASSOCIATION_COPY_NONATOMIC);

}

- (CGRect)jhLargeRect{

    NSNumber *topEdge = objc_getAssociatedObject(self, &topNameKey);

    NSNumber *leftEdge = objc_getAssociatedObject(self, &leftNameKey);

    NSNumber *bottomEdge = objc_getAssociatedObject(self, &bottomNameKey);

    NSNumber *rightEdge = objc_getAssociatedObject(self, &rightNameKey);

    if (topEdge && leftEdge && bottomEdge && rightEdge) {

        return CGRectMake(self.bounds.origin.x - leftEdge.floatValue, self.bounds.origin.y - topEdge.floatValue, self.bounds.size.width+leftEdge.floatValue+rightEdge.floatValue, self.bounds.size.height+topEdge.floatValue+bottomEdge.floatValue);

    }else{

        return self.bounds;

    }

}

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

    CGRect rect = [self jhLargeRect];

    if (CGRectEqualToRect(rect, self.bounds)) {

        return [super hitTest:point withEvent:event];

    }

    return CGRectContainsPoint(rect, point) ? self : nil;

}

@end

根据需求自行选择方法调用即可