有几个实际业务场景需要控制UIButton响应事件的时间间隔。比如：
1、当通过点击按钮来执行网络请求时，若请求耗时稍长，用户往往会再点一次。这样，就执行了两次请求，造成了资源浪费。
2、在移动终端性能较差时（比如iPhone 6升级到iOS 11😅），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。
控制按钮响应事件时间间隔的方案不止一种。比如：
- 方案 1：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，常常涉及多个方法。
- (void)buttonClicked:(UIButton *)sender { sender.enabled = NO; dispatch_after(dispatch_time(DISPATCH_TIME_NOW, (int64_t)(2.0 * NSEC_PER_SEC)), dispatch_get_main_queue(), ^{ sender.enabled = YES; }); } - 方案2：通过NSObject的
+cancelPreviousPerformRequestsWithTarget:selector:object:方法和-performSelector:withObject:afterDelay:方法控制按钮的响应事件的执行时间间隔。此方案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，会出现延迟现象。
- (void)buttonClicked:(UIButton *)sender { [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(buttonClickedAction:) object:sender]; [self performSelector:@selector(buttonClickedAction:) withObject:sender afterDelay:2.0]; } 在需要对大量UIButton做控制的场景中，方案1和方案2会比较不方便。针对此场景，着重说一下方案3。
- 方案3：通过Runtime控制UIButton响应事件的时间间隔。思路如下：
1、创建一个UIButton的类别，使用runtime为UIButton增加public属性qi_eventInterval和private属性eventUnavailable。
2、在+load方法中使用runtime将UIButton的-sendAction:to:forEvent:方法与自定义的-qi_sendAction:to:forEvent:方法交换Implementation。
3、使用qi_eventInterval作为控制eventUnavailable的计时因子，用eventUnavailable开控制UIButton的event事件是否有效。
方案3可以对所有UIButton生效，具体实现代码如下：
@interface UIButton (QiEventInterval) @property (nonatomic, assign) NSTimeInterval qi_eventInterval; @end #import "UIButton+QiEventInterval.h" #import <objc/runtime.h> static char * const qi_eventIntervalKey = "qi_eventIntervalKey"; static char * const eventUnavailableKey = "eventUnavailableKey"; @interface UIButton () @property (nonatomic, assign) BOOL eventUnavailable; @end @implementation UIButton (QiEventInterval) + (void)load { Method method = class_getInstanceMethod(self, @selector(sendAction:to:forEvent:)); Method qi_method = class_getInstanceMethod(self, @selector(qi_sendAction:to:forEvent:)); method_exchangeImplementations(method, qi_method); } #pragma mark - Action functions //- (void)qi_sendAction:(SEL)action to:(id)target forEvent:(UIEvent *)event { // if (self.eventUnavailable == NO) { // self.eventUnavailable = YES; // [self qi_sendAction:action to:target forEvent:event]; // [self performSelector:@selector(setEventUnavailable:) withObject:@(NO) afterDelay:self.qi_eventInterval]; // } //} - (void)qi_sendAction:(SEL)action to:(id)target forEvent:(UIEvent *)event { if([self isMemberOfClass:[UIButton class]]) { if (self.eventUnavailable == NO) { self.eventUnavailable = YES; [self qi_sendAction:action to:target forEvent:event]; [self performSelector:@selector(setEventUnavailable:) withObject:0 afterDelay:self.qi_eventInterval]; } } else { [self qi_sendAction:action to:target forEvent:event]; } } #pragma mark - Setter & Getter functions - (NSTimeInterval)qi_eventInterval { return [objc_getAssociatedObject(self, qi_eventIntervalKey) doubleValue]; } - (void)setQi_eventInterval:(NSTimeInterval)qi_eventInterval { objc_setAssociatedObject(self, qi_eventIntervalKey, @(qi_eventInterval), OBJC_ASSOCIATION_RETAIN_NONATOMIC); } - (BOOL)eventUnavailable { return [objc_getAssociatedObject(self, eventUnavailableKey) boolValue]; } - (void)setEventUnavailable:(BOOL)eventUnavailable { objc_setAssociatedObject(self, eventUnavailableKey, @(eventUnavailable), OBJC_ASSOCIATION_RETAIN_NONATOMIC); } @end
使用方法:
UIButton *button = [UIButton buttonWithType:UIButtonTypeSystem];
/* here is some button's configuration codes */
[self.view addSubview:button];
//! 设置按钮的点击响应间隔时间
button.qi_eventInterval = 2.0;
效果展示：
-
默认Button点击效果：
不设置qi_eventInterval (默认为0) -
设置qi_eventInterval为2秒：
设置qi_eventInterval为2秒
PS：针对方案3，因为在
UIButton+QiEventInterval.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+QiEventInterval改成UIControl+QiEventInterval以避免此问题。
可从Github获取工程源码
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iOS 计算时间差 避免过度使用定时器
(2017-12-13 19:49:46)NSString *recordDate = [[NSUserDefaultsstandardUserDefaults]objectForKey:@"recordDate"];
if (recordDate.length != 0) {
NSDate *nowDate = [NSDate date]; // 当前时间
NSDateFormatter *formatter = [[NSDateFormatter alloc]init];
[formatter setDateFormat:@"yyyy/MM/dd HH:mm:ss:SSS"];
NSString*timeString=[formatter stringFromDate: nowDate];
double timeDiff = 0.0;
NSDateFormatter *formatters = [[NSDateFormatter alloc]init];
[formatters setDateFormat:@"yyyy/MM/dd HH:mm:ss:SSS"];
NSDate *dateS = [formatters dateFromString:recordDate];
NSDateFormatter *formatterE = [[NSDateFormatter alloc]init];
[formatterE setDateFormat:@"yyyy/MM/dd HH:mm:ss:SSS"];
NSDate *dateE = [formatterE dateFromString:timeString];
timeDiff = [dateE timeIntervalSinceDate:dateS ];
int myInt = (int)timeDiff;
if (myInt < 20) {
MBProgressHUD *hud = [[MBProgressHUD alloc] init];
[self.view addSubview:hud];
hud.labelText = @"请勿频繁操作";//@"网络连接失败";
hud.mode = MBProgressHUDModeText;
[hud showAnimated:YES whileExecutingBlock:^{
sleep(1);
} completionBlock:^{
[hud removeFromSuperview];
}];
return;
}
}
#pragma mark-保存本地时间到沙盒
-(void)currentDateString{
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy/MM/dd HH:mm:ss:SSS"];
NSString*timeString=[formatter stringFromDate: [NSDate date]];
// NSDate *currentDate = [NSDate date];
// NSString *currentDateString = [NSString stringWithFormat:@"%ld", (long)[currentDate timeIntervalSince1970]];
[[NSUserDefaults standardUserDefaults] setObject:timeStringforKey:@"recordDate"];
[[NSUserDefaults standardUserDefaults] synchronize];
}
作者：QiShare
链接：https://www.jianshu.com/p/c2243ac4f620
来源：简书
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