NSTimer扩展block版 | 标哥的技术博客

序言

对于定时器，基本每个应用都使用需要到的，但是原生API使用起来并不是那么方便，还得处理各种回调，对于开发时相对复杂了。因此，尝试写下这个block版本的，以简化调用！！！

头文件

下面是扩展的头文件，看看公开了哪些API：

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// //  NSTimer+Convenience.h //  NSTimerBlockDemo // //  Created by huangyibiao on 15/3/25. //  Copyright (c) 2015年 huangyibiao. All rights reserved. // #import <Foundation/Foundation.h> @interface NSTimer (Convenience) /** *  无参数无返回值Block */ typedef void (^HYBVoidBlock)(void); /** *  创建Timer---Block版本 * *  @param interval 每隔interval秒就回调一次callback *  @param repeats  是否重复 *  @param callback 回调block * *  @return NSTimer对象 */ + (NSTimer *)scheduledTimerWithTimeInterval:(NSTimeInterval)interval                                     repeats:(BOOL)repeats                                    callback:(HYBVoidBlock)callback; /** *  创建Timer---Block版本 * *  @param interval 每隔interval秒就回调一次callback *  @param count  回调多少次后自动暂停，如果count <= 0，则表示无限次，否则表示具体的次数 *  @param callback 回调block * *  @return NSTimer对象 */ + (NSTimer *)scheduledTimerWithTimeInterval:(NSTimeInterval)interval                                     count:(NSInteger)count                                    callback:(HYBVoidBlock)callback; /** *  开始启动定时器 */ - (void)fireTimer; /** *  暂停定时器 */ - (void)unfireTimer; @end

实现文件

重点是实现文件，这里使用了非常巧妙的方式：让NSTimer本身的userInfo属性来存储回调！

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// //  NSTimer+Convenience.m //  NSTimerBlockDemo // //  Created by huangyibiao on 15/3/25. //  Copyright (c) 2015年 huangyibiao. All rights reserved. // #import "NSTimer+Convenience.h" @implementation NSTimer (Convenience) + (NSTimer *)scheduledTimerWithTimeInterval:(NSTimeInterval)interval                                     repeats:(BOOL)repeats                                    callback:(HYBVoidBlock)callback {   return [NSTimer scheduledTimerWithTimeInterval:interval                                           target:self                                         selector:@selector(onTimerUpdateBlock:)                                         userInfo:[callback copy]                                          repeats:repeats]; } + (NSTimer *)scheduledTimerWithTimeInterval:(NSTimeInterval)interval                                       count:(NSInteger)count                                    callback:(HYBVoidBlock)callback {   NSDictionary *userInfo = @{@"callback"     : [callback copy],                              @"count"        : @(count)};   return [NSTimer scheduledTimerWithTimeInterval:interval                                           target:self                                         selector:@selector(onTimerUpdateCountBlock:)                                         userInfo:userInfo                                          repeats:YES]; } + (void)onTimerUpdateBlock:(NSTimer *)timer {   HYBVoidBlock block = timer.userInfo;      if (block) {     block();   } } + (void)onTimerUpdateCountBlock:(NSTimer *)timer {   static NSUInteger currentCount = 0;      NSDictionary *userInfo = timer.userInfo;   HYBVoidBlock callback = userInfo[@"callback"];   NSNumber *count = userInfo[@"count"];      if (count.integerValue <= 0) {     if (callback) {       callback();     }   } else {     if (currentCount < count.integerValue) {       currentCount++;       if (callback) {         callback();       }     } else {       currentCount = 0;              [timer unfireTimer];       [timer invalidate];       timer = nil;     }   } } - (void)fireTimer {   [self setFireDate:[NSDate distantPast]]; } - (void)unfireTimer {   [self setFireDate:[NSDate distantFuture]]; } @end

代码中很关键的代码，获取回调，再获取已经回调了的次数，用于处理回调次数限制的情况：

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NSDictionary *userInfo = timer.userInfo; HYBVoidBlock callback = userInfo[@"callback"]; NSNumber *count = userInfo[@"count"];

源代码

想要下载Demo？狂点这里：https://github.com/CoderJackyHuang/HYBTimerExtension