通过扩展属性实现增大UIButton的frame外点击范围

开发中总是遇到测试反馈小图标按钮点击没反应的问题，不是没反应是设计的太小了，真是太小了，此时就会提看起来小用起来大的要求，安排！

Swift版

import Foundation
import UIKit

extension UIButton {
    
    // 增加点击边距的扩展属性
    private struct HitEdgeInsetsAssociatedKeys {
        static var hitTestEdgeInsets: UIEdgeInsets = .zero
    }

    @objc var hitTestEdgeInsets: UIEdgeInsets {
        
        get {
            return objc_getAssociatedObject(self, &HitEdgeInsetsAssociatedKeys.hitTestEdgeInsets) as! UIEdgeInsets
        }
        
        set(newValue) {
            objc_setAssociatedObject(self, &HitEdgeInsetsAssociatedKeys.hitTestEdgeInsets, newValue, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
        }
    }
    
    open override func point(inside point: CGPoint, with event: UIEvent?) -> Bool {
        if self.hitTestEdgeInsets == UIEdgeInsets.zero || !self.isEnabled || self.isHidden {
            return super.point(inside: point, with: event)
        }
        let relativeFrame = self.bounds
        let hitFrame = relativeFrame.inset(by: self.hitTestEdgeInsets);
        return CGRectContainsPoint(hitFrame, point);
    }    
}

使用

yourButton.hitTestEdgeInsets  = UIEdgeInsetsMake(-20, -20, -20, -10)

OC版

UIButton+HitEdgeInsets.h

#import <UIKit/UIKit.h>

NS_ASSUME_NONNULL_BEGIN

@interface UIButton (HitEdgeInsets)

@property (nonatomic, assign) UIEdgeInsets hitTestEdgeInsets;

@end

NS_ASSUME_NONNULL_END

import "UIButton+HitEdgeInsets.m

#import "UIButton+HitEdgeInsets.h"

@implementation UIButton (HitEdgeInsets)

@dynamic hitTestEdgeInsets;

static const NSString *Associated_KEY_HIT_TEST_EDGE_INSETS = @"HitTestEdgeInsets";

- (void)setHitTestEdgeInsets:(UIEdgeInsets)hitTestEdgeInsets {
    NSValue *value = [NSValue value:&hitTestEdgeInsets withObjCType:@encode(UIEdgeInsets)];
    objc_setAssociatedObject(self, &Associated_KEY_HIT_TEST_EDGE_INSETS, value, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (UIEdgeInsets)hitTestEdgeInsets {
    NSValue *value = objc_getAssociatedObject(self, &Associated_KEY_HIT_TEST_EDGE_INSETS);
    if(value) {
        UIEdgeInsets edgeInsets; [value getValue:&edgeInsets]; return edgeInsets;
    }else {
        return UIEdgeInsetsZero;
    }
}

- (BOOL)pointInside:(CGPoint)point withEvent:(UIEvent *)event {
    if(UIEdgeInsetsEqualToEdgeInsets(self.hitTestEdgeInsets, UIEdgeInsetsZero) ||       !self.enabled || self.hidden) {
        return [super pointInside:point withEvent:event];
    }
    
    CGRect relativeFrame = self.bounds;
    CGRect hitFrame = UIEdgeInsetsInsetRect(relativeFrame, self.hitTestEdgeInsets);
    
    return CGRectContainsPoint(hitFrame, point);
}

@end