iOS-UIButton防止重复点击(三种办法)

目录

• 使用场景
• 方法一 设置enabled或userInteractionEnabled属性
• 方法二 借助cancelPreviousPerformRequestsWithTarget:selector:object实现
• 方法三 通过runtime交换方法实现
• 注意事项

一 使用场景

在实际应用场景中，有几个业务场景需要控制UIButton响应事件的时间间隔。

• 1 当点击按钮来执行网络请求时，若请求耗时稍长，用户往往会多次点击。这样，就执行了多次请求，造成资源浪费。
• 2 在移动终端设备性能较差时，连续点击按钮会执行多次事件（比如push出来多个viewController）。
• 3 防止暴力点击。

二 方法一

通过UIButton的enabled属性和userInteractionEnabled属性控制按钮是否可点击。此方案在逻辑上比较清晰、易懂，但具体代码书写分散，常常涉及多个地方。

• 创建按钮

- (void)drawBtn {UIButton *btn = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 200, 100)];[btn setTitle:@"按钮点击" forState:UIControlStateNormal];[btn setTitleColor:[UIColor redColor] forState:UIControlStateNormal];// 按钮不可点击时,文字颜色置灰[btn setTitleColor:[UIColor grayColor] forState:UIControlStateDisabled];[btn setTitleColor:[UIColor blueColor] forState:UIControlStateHighlighted];btn.center = self.view.center;[btn addTarget:self action:@selector(tapBtn:) forControlEvents:UIControlEventTouchUpInside];[self.view addSubview:btn];
}

按钮不可点击时，标题颜色置灰，方便对比

• 点击事件

- (void)tapBtn:(UIButton *)btn {NSLog(@"按钮点击...");btn.enabled = NO;dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{btn.enabled = YES;});
}

运行结果

1.gif

2019-06-12 23:21:09.039455+0800 AvoidBtnRepeatClick[8102:362250] 按钮点击...
2019-06-12 23:21:11.658751+0800 AvoidBtnRepeatClick[8102:362250] 按钮点击...
2019-06-12 23:21:14.057510+0800 AvoidBtnRepeatClick[8102:362250] 按钮点击...
2019-06-12 23:21:16.254230+0800 AvoidBtnRepeatClick[8102:362250] 按钮点击...
2019-06-12 23:21:18.788004+0800 AvoidBtnRepeatClick[8102:362250] 按钮点击...
2019-06-12 23:21:21.155584+0800 AvoidBtnRepeatClick[8102:362250] 按钮点击...
2019-06-12 23:21:23.389769+0800 AvoidBtnRepeatClick[8102:362250] 按钮点击...

每隔2秒执行一次方法

方法二

通过 NSObject 的两个方法

// 此方法会在连续点击按钮时取消之前的点击事件，从而只执行最后一次点击事件
+ (void)cancelPreviousPerformRequestsWithTarget:(id)aTarget selector:(SEL)aSelector object:(nullable id)anArgument;
// 多长时间后做某件事情
- (void)performSelector:(SEL)aSelector withObject:(nullable id)anArgument afterDelay:(NSTimeInterval)delay;

按钮创建还是上面代码

• 按钮点击事件如下

/** 方法一 */
- (void)tapBtn:(UIButton *)btn {NSLog(@"按钮点击了...");// 此方法会在连续点击按钮时取消之前的点击事件，从而只执行最后一次点击事件[NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(buttonClickedAction:) object:btn];// 多长时间后做某件事情[self performSelector:@selector(buttonClickedAction:) withObject:btn afterDelay:2.0];
}- (void)buttonClickedAction:(UIButton *)btn {NSLog(@"真正开始执行业务 - 比如网络请求...");
}

• 运行结果

1.gif

2019-06-13 09:15:58.935540+0800 AvoidBtnRepeatClick[62321:2927724] 按钮点击了...
2019-06-13 09:15:59.284096+0800 AvoidBtnRepeatClick[62321:2927724] 按钮点击了...
2019-06-13 09:15:59.760772+0800 AvoidBtnRepeatClick[62321:2927724] 按钮点击了...
2019-06-13 09:16:00.238923+0800 AvoidBtnRepeatClick[62321:2927724] 按钮点击了...
2019-06-13 09:16:00.689305+0800 AvoidBtnRepeatClick[62321:2927724] 按钮点击了...
2019-06-13 09:16:02.689633+0800 AvoidBtnRepeatClick[62321:2927724] 真正开始执行业务 - 比如网络请求...
2019-06-13 09:16:03.479984+0800 AvoidBtnRepeatClick[62321:2927724] 按钮点击了...
2019-06-13 09:16:03.884124+0800 AvoidBtnRepeatClick[62321:2927724] 按钮点击了...
2019-06-13 09:16:04.334930+0800 AvoidBtnRepeatClick[62321:2927724] 按钮点击了...
2019-06-13 09:16:04.776324+0800 AvoidBtnRepeatClick[62321:2927724] 按钮点击了...
2019-06-13 09:16:05.179153+0800 AvoidBtnRepeatClick[62321:2927724] 按钮点击了...
2019-06-13 09:16:07.179512+0800 AvoidBtnRepeatClick[62321:2927724] 真正开始执行业务 - 比如网络请求...
2019-06-13 09:16:08.062850+0800 AvoidBtnRepeatClick[62321:2927724] 按钮点击了...
2019-06-13 09:16:10.064171+0800 AvoidBtnRepeatClick[62321:2927724] 真正开始执行业务 - 比如网络请求...
2019-06-13 09:16:10.947205+0800 AvoidBtnRepeatClick[62321:2927724] 按钮点击了...
2019-06-13 09:16:12.948065+0800 AvoidBtnRepeatClick[62321:2927724] 真正开始执行业务 - 比如网络请求...
2019-06-13 09:16:13.528897+0800 AvoidBtnRepeatClick[62321:2927724] 按钮点击了...
2019-06-13 09:16:13.776711+0800 AvoidBtnRepeatClick[62321:2927724] 按钮点击了...
2019-06-13 09:16:15.777735+0800 AvoidBtnRepeatClick[62321:2927724] 真正开始执行业务 - 比如网络请求...

通过打印结果可知，如果连续点击多次，只会响应最后一次点击事件，并且是在设定的时间间隔后执行，这边设置的时间间隔是 2S。

总结：会出现延时现象，并且需要对大量的UIButton做处理，工作量大，不方便。

方法三

通过Runtime交换UIButton的响应事件方法，从而控制响应事件的时间间隔。

实现步骤如下:

• 1 创建一个UIButton的分类，使用runtime增加public属性cs_eventInterval和private属性cs_eventInvalid。
• 2 在+load方法中使用runtime将UIButton的-sendAction:to:forEvent:方法与自定义的cs_sendAction:to:forEvent:方法进行交换
• 3 使用cs_eventInterval作为控制cs_eventInvalid的计时因子，用cs_eventInvalid控制UIButton的event事件是否有效。

*代码实现如下

@interface UIButton (Extension)/** 时间间隔 */
@property(nonatomic, assign)NSTimeInterval cs_eventInterval;@end

#import "UIButton+Extension.h"
#import <objc/runtime.h>static char *const kEventIntervalKey = "kEventIntervalKey"; // 时间间隔
static char *const kEventInvalidKey = "kEventInvalidKey";   // 是否失效@interface UIButton()/** 是否失效 - 即不可以点击 */
@property(nonatomic, assign)BOOL cs_eventInvalid;@end@implementation UIButton (Extension)+ (void)load {// 交换方法Method clickMethod = class_getInstanceMethod(self, @selector(sendAction:to:forEvent:));Method cs_clickMethod = class_getInstanceMethod(self, @selector(cs_sendAction:to:forEvent:));method_exchangeImplementations(clickMethod, cs_clickMethod);
}#pragma mark - click- (void)cs_sendAction:(SEL)action to:(id)target forEvent:(UIEvent *)event {if (!self.cs_eventInvalid) {self.cs_eventInvalid = YES;[self cs_sendAction:action to:target forEvent:event];[self performSelector:@selector(setCs_eventInvalid:) withObject:@(NO) afterDelay:self.cs_eventInterval];}
}#pragma mark - set | get- (NSTimeInterval)cs_eventInterval {return [objc_getAssociatedObject(self, kEventIntervalKey) doubleValue];
}- (void)setCs_eventInterval:(NSTimeInterval)cs_eventInterval {objc_setAssociatedObject(self, kEventIntervalKey, @(cs_eventInterval), OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}- (BOOL)cs_eventInvalid {return [objc_getAssociatedObject(self, kEventInvalidKey) boolValue];
}- (void)setCs_eventInvalid:(BOOL)cs_eventInvalid {objc_setAssociatedObject(self, kEventInvalidKey, @(cs_eventInvalid), OBJC_ASSOCIATION_RETAIN_NONATOMIC);
}

• 测试代码如下

/** 方法三 */
- (void)drawExpecialBtn{UIButton *btn = [[UIButton alloc] initWithFrame:CGRectMake(0, 0, 200, 100)];[btn setTitle:@"按钮点击" forState:UIControlStateNormal];[btn setTitleColor:[UIColor redColor] forState:UIControlStateNormal];// 按钮不可点击时,文字颜色置灰[btn setTitleColor:[UIColor grayColor] forState:UIControlStateDisabled];[btn setTitleColor:[UIColor blueColor] forState:UIControlStateHighlighted];btn.center = self.view.center;[btn addTarget:self action:@selector(tapBtn:) forControlEvents:UIControlEventTouchUpInside];btn.cs_eventInterval = 2.0;[self.view addSubview:btn];
}- (void)tapBtn:(UIButton *)btn {NSLog(@"按钮点击...");
}

• 运行结果如下

1.gif

2019-06-13 19:18:48.314110+0800 AvoidBtnRepeatClick[89795:3312038] 按钮点击...
2019-06-13 19:18:50.346907+0800 AvoidBtnRepeatClick[89795:3312038] 按钮点击...
2019-06-13 19:18:52.512887+0800 AvoidBtnRepeatClick[89795:3312038] 按钮点击...
2019-06-13 19:18:54.515119+0800 AvoidBtnRepeatClick[89795:3312038] 按钮点击...
2019-06-13 19:18:56.577693+0800 AvoidBtnRepeatClick[89795:3312038] 按钮点击...
2019-06-13 19:18:58.679121+0800 AvoidBtnRepeatClick[89795:3312038] 按钮点击...
2019-06-13 19:19:00.681003+0800 AvoidBtnRepeatClick[89795:3312038] 按钮点击...
2019-06-13 19:19:02.752387+0800 AvoidBtnRepeatClick[89795:3312038] 按钮点击...
2019-06-13 19:19:04.879559+0800 AvoidBtnRepeatClick[89795:3312038] 按钮点击...

四 注意事项

在方法三中交互UIButton的sendAction:to:forEvent:方法,实际上交互的是UIControl的sendAction:to:forEvent:方法，所以在使用·UIControl·或其·子类（比如UISlider）·的·sendAction:to:forEvent:·方法时会引起参数缺失的崩溃。

• 测试代码如下

/** 注意事项 */
- (void)slideTest {UISlider *slide = [[UISlider alloc] initWithFrame:CGRectMake(0, 0, 200, 59)];[slide addTarget:self action:@selector(tapSlide:) forControlEvents:UIControlEventTouchUpInside];slide.center = self.view.center;[self.view addSubview:slide];
}- (void)tapSlide:(UISlider *)slider {NSLog(@"UISlider点击...");
}

运行结果

image.png

(void *) $0 = 0x0000600002620000
2019-06-13 19:48:22.753320+0800 AvoidBtnRepeatClick[90086:3328087]  INFO: Reveal Server started (Protocol Version 32).
2019-06-13 19:48:26.329630+0800 AvoidBtnRepeatClick[90086:3328087] -[UISlider cs_eventInvalid]: unrecognized selector sent to instance 0x7ffd79c0f4d0
2019-06-13 19:48:26.340542+0800 AvoidBtnRepeatClick[90086:3328087] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[UISlider cs_eventInvalid]: unrecognized selector sent to instance 0x7ffd79c0f4d0'
*** First throw call stack:
(0   CoreFoundation                      0x0000000110be26fb __exceptionPreprocess + 3311   libobjc.A.dylib                     0x0000000110186ac5 objc_exception_throw + 482   CoreFoundation                      0x0000000110c00ab4 -[NSObject(NSObject) doesNotRecognizeSelector:] + 1323   UIKitCore                           0x000000011397cc3d -[UIResponder doesNotRecognizeSelector:] + 2874   CoreFoundation                      0x0000000110be7443 ___forwarding___ + 14435   CoreFoundation                      0x0000000110be9238 _CF_forwarding_prep_0 + 1206   AvoidBtnRepeatClick                 0x000000010f8af1cb -[UIButton(Extension) cs_sendAction:to:forEvent:] + 917   UIKitCore                           0x00000001133a7f36 -[UIControl _sendActionsForEvents:withEvent:] + 4508   UIKitCore                           0x00000001133a6eec -[UIControl touchesEnded:withEvent:] + 5839   UIKitCore                           0x000000011398aeee -[UIWindow _sendTouchesForEvent:] + 254710  UIKitCore                           0x000000011398c5d2 -[UIWindow sendEvent:] + 407911  UIKitCore                           0x000000011396ad16 -[UIApplication sendEvent:] + 35612  UIKitCore                           0x0000000113a3b293 __dispatchPreprocessedEventFromEventQueue + 323213  UIKitCore                           0x0000000113a3dbb9 __handleEventQueueInternal + 591114  CoreFoundation                      0x0000000110b49be1 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 1715  CoreFoundation                      0x0000000110b49463 __CFRunLoopDoSources0 + 24316  CoreFoundation                      0x0000000110b43b1f __CFRunLoopRun + 123117  CoreFoundation                      0x0000000110b43302 CFRunLoopRunSpecific + 62618  GraphicsServices                    0x00000001190d22fe GSEventRunModal + 6519  UIKitCore                           0x0000000113950ba2 UIApplicationMain + 14020  AvoidBtnRepeatClick                 0x000000010f8af500 main + 11221  libdyld.dylib                       0x00000001124c1541 start + 122  ???                                 0x0000000000000001 0x0 + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb) 

注意：因为在UIButton+Extension.m中的+load方法中交换了UIControl的sendAction:to:forEvent:方法，所以在使用UIControl或其子类（比如UISlider）的sendAction:to:forEvent:方法时会引起参数缺失的崩溃。可以将UIButton+Extension改成UIControl+Extension以避免此问题。