有幾個實際業務場景需要控制UIButton響應事件的時間間隔。比如：
1、當通過點擊按鈕來執行網絡請求時，若請求耗時稍長，用戶往往會再點一次。這樣，就執行了兩次請求，造成了資源浪費。
2、在移動終端性能較差時（比如iPhone 6升級到iOS 11😅），連續點擊按鈕會執行多次事件（比如push出來多個viewController）。
3、防止暴力點擊。
控制按鈕響應事件時間間隔的方案不止一種。比如：
- 方案 1：通過
UIButton的enabled屬性和userInteractionEnabled屬性控制按鈕是否可點擊。此方案在邏輯上比較清晰、易懂，但具體代碼書寫分散，常常涉及多個方法。
- (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：通過NSObject的
+cancelPreviousPerformRequestsWithTarget:selector:object:方法和-performSelector:withObject:afterDelay:方法控制按鈕的響應事件的執行時間間隔。此方案會在連續點擊按鈕時取消之前的點擊事件，從而只執行最后一次點擊事件，會出現延遲現象。
- (void)buttonClicked:(UIButton *)sender { [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(buttonClickedAction:) object:sender]; [self performSelector:@selector(buttonClickedAction:) withObject:sender afterDelay:2.0]; } 在需要對大量UIButton做控制的場景中，方案1和方案2會比較不方便。針對此場景，着重說一下方案3。
- 方案3：通過Runtime控制UIButton響應事件的時間間隔。思路如下：
1、創建一個UIButton的類別，使用runtime為UIButton增加public屬性qi_eventInterval和private屬性eventUnavailable。
2、在+load方法中使用runtime將UIButton的-sendAction:to:forEvent:方法與自定義的-qi_sendAction:to:forEvent:方法交換Implementation。
3、使用qi_eventInterval作為控制eventUnavailable的計時因子，用eventUnavailable開控制UIButton的event事件是否有效。
方案3可以對所有UIButton生效，具體實現代碼如下：
@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];
//! 設置按鈕的點擊響應間隔時間
button.qi_eventInterval = 2.0;
效果展示：
-
默認Button點擊效果：
不設置qi_eventInterval (默認為0) -
設置qi_eventInterval為2秒：
設置qi_eventInterval為2秒
PS：針對方案3，因為在
UIButton+QiEventInterval.m中的+load方法中交換了UIControl的sendAction:to:forEvent:方法，所以在使用UIControl或其子類（比如UISlider）的sendAction:to:forEvent:方法時會引起參數缺失的崩潰。可以將UIButton+QiEventInterval改成UIControl+QiEventInterval以避免此問題。
可從Github獲取工程源碼
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iOS 計算時間差 避免過度使用定時器
(2017-12-13 19:49:46)NSString *recordDate = [[NSUserDefaultsstandardUserDefaults]objectForKey:@"recordDate"];
if (recordDate.length != 0) {
NSDate *nowDate = [NSDate date]; // 當前時間
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 = @"請勿頻繁操作";//@"網絡連接失敗";
hud.mode = MBProgressHUDModeText;
[hud showAnimated:YES whileExecutingBlock:^{
sleep(1);
} completionBlock:^{
[hud removeFromSuperview];
}];
return;
}
}
#pragma mark-保存本地時間到沙盒
-(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
鏈接：https://www.jianshu.com/p/c2243ac4f620
來源：簡書
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