解决 UIButton 快速点击后重复提交数据

有时候我们快速点击按钮多次，会触发多次点击事件，最终导致数据提交多次，这是很没必要的。

说明

• 默认开启防重复点击功能，默认间隔时间 0.5 秒

如果你的按钮有特殊的需求，可以通过将 enabledRejectRepeatTap 设置为 NO 来禁用该功能。

代码

• UIButton+RejectRepeatTapGesture.h 头文件代码

#import <UIKit/UIKit.h>

/// 解决按钮快速点击重复提交数据的问题
@interface UIButton (RejectRepeatTapGesture)

/// 重复点击的时间间隔, 默认`0.5s`
@property (nonatomic, assign) IBInspectable double repeatTimeInterval;
/// 是否启用防重复功能, 默认`YES`
@property (nonatomic, assign, getter=isEnabledRejectRepeatTap) IBInspectable BOOL enabledRejectRepeatTap;

@end


/// 回调, 按钮的`target`对象遵守该协议即可接收回调事件
@protocol UIButtonRejectRepeatTapGestureCallback <NSObject>

/**
 当重复点击时的回调方法

 @param button 被点击的按钮
 @param timeInterval 两次点击之间的时间间隔
 */
- (void)rejectRepeatTapGestureFromButton:(UIButton *)button timeInterval:(NSTimeInterval)timeInterval;

@end

• UIButton+RejectRepeatTapGesture.m 代码

#import "UIButton+RejectRepeatTapGesture.h"
#import <objc/message.h>

static char const kRepeatTapRecordsKey = '\0';

@implementation UIButton (RejectRepeatTapGesture)

#pragma mark - Lifecycle

+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        SEL originalSelector = @selector(sendAction:to:forEvent:);
        SEL swizllingSelector = @selector(rrtg_sendAction:to:forEvent:);
        Method originalMethod = class_getInstanceMethod(self, originalSelector);
        Method swizllingMethod = class_getInstanceMethod(self, swizllingSelector);
        BOOL flag = class_addMethod(self, originalSelector, method_getImplementation(swizllingMethod), method_getTypeEncoding(swizllingMethod));
        if (flag) {
            class_replaceMethod(self, swizllingSelector, method_getImplementation(originalMethod), method_getTypeEncoding(originalMethod));
        } else {
            method_exchangeImplementations(originalMethod, swizllingMethod);
        }
    });
}

/**
 重写`sendAction:to:forEvent:`系统方法
 
 根据`target-action`来确定唯一的key，在规定时间内避免多次触发`[target action]`
 通过该机制能够有效避免类似 UIImagePickerController 的拍照按钮以及 UITableView 的左滑删除按钮点击无效的问题
 */
- (void)rrtg_sendAction:(SEL)action to:(id)target forEvent:(UIEvent *)event {
    if (event.type == UIEventTypeTouches && self.isEnabledRejectRepeatTap) {
        NSString * const key = [NSString stringWithFormat:@"%p%p", action, target];
        NSMutableDictionary *dictionary = objc_getAssociatedObject(self, &kRepeatTapRecordsKey);
        if (dictionary == nil) {
            dictionary = [NSMutableDictionary dictionary];
            objc_setAssociatedObject(self, &kRepeatTapRecordsKey, dictionary, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
        }
        NSTimeInterval lasttimeTapTime = [[dictionary objectForKey:key] doubleValue];
        NSTimeInterval currentTime = [[NSDate date] timeIntervalSince1970];
        if (lasttimeTapTime > 0.0) {
            NSTimeInterval interval = currentTime - lasttimeTapTime;
            if (interval <= self.repeatTimeInterval) {
                if ([target conformsToProtocol:@protocol(UIButtonRejectRepeatTapGestureCallback)]) {
                    id<UIButtonRejectRepeatTapGestureCallback> delegate = (id<UIButtonRejectRepeatTapGestureCallback>)target;
                    [delegate rejectRepeatTapGestureFromButton:self timeInterval:interval];
                }
                return;
            }
        }
        [dictionary setObject:@(currentTime) forKey:key];
    }
    [self rrtg_sendAction:action to:target forEvent:event];
}

#pragma mark - setter & getter

- (void)setRepeatTimeInterval:(NSTimeInterval)repeatTimeInterval {
    objc_setAssociatedObject(self,
                             @selector(repeatTimeInterval),
                             @(repeatTimeInterval),
                             OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (NSTimeInterval)repeatTimeInterval {
    NSTimeInterval timeInterval = [objc_getAssociatedObject(self, _cmd) doubleValue];
    if (timeInterval >= 0.01) {
        return timeInterval;
    }
    return 0.5; // default.
}

- (void)setEnabledRejectRepeatTap:(BOOL)enabledRejectRepeatTap {
    objc_setAssociatedObject(self,
                             @selector(isEnabledRejectRepeatTap),
                             @(enabledRejectRepeatTap),
                             OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

- (BOOL)isEnabledRejectRepeatTap {
    id obj = objc_getAssociatedObject(self, _cmd);
    if (obj) {
        return [obj boolValue];
    }
    return YES; // default.
}

@end