执行延迟IOS关于取消延迟执行函数的种种

来源：互联网发布：java socket连接编辑：程序博客网时间：2024/05/21 17:39

写这篇博客要主是加深自己对执行延迟的认识和总结实现算法时的一些验经和训教，如果有错误请指出，万分感谢。

@interface NSObject (NSDelayedPerforming)

- (void)performSelector:(SEL)aSelector withObject:(id)anArgument afterDelay:(NSTimeInterval)delay inModes:(NSArray *)modes;

- (void)performSelector:(SEL)aSelector withObject:(id)anArgument afterDelay:(NSTimeInterval)delay;

+ (void)cancelPreviousPerformRequestsWithTarget:(id)aTarget selector:(SEL)aSelector object:(id)anArgument;

+ (void)cancelPreviousPerformRequestsWithTarget:(id)aTarget;

@end

</pre><pre name="code" class="java" style="margin-top: 0px; margin-bottom: 0px; padding: 0px;font-size:12px; font-family: consolas, 'Courier New', courier, monospace; white-space: pre-line; line-height: 30px; background-color: rgb(255, 255, 255);">最近看到大家对cancelPreviousPerformRequestsWithTarget不能取消带参数的

- (void)performSelector:(SEL)aSelector withObject:(id)anArgument afterDelay:(NSTimeInterval)delay;

情况，写了一点点代码调试了一下，发现如果是带参数，那取消时的参数也要分歧，否则不能取消胜利。

[self performSelector:@selector(didRuninCurrModel:) withObject:[NSNumber numberWithBool:YES] afterDelay:3.0f];

[self performSelector:@selector(didRuninCurrModelNoArgument) withObject:nil afterDelay:3.0f];

假如在三秒内执行以下取消方法，则结果分别为：

[NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(didRuninCurrModel:) object:[NSNumber numberWithBool:YES]];//可以取消胜利。

[NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(didRuninCurrModel:) object:[NSNumber numberWithBool:NO]];//不能取消胜利。参数不匹配

[NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(didRuninCurrModel:) object:nil];//不能取消胜利。参数不匹配

[NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(didRuninCurrModelNoArgument) object:nil];//可以胜利取消

[NSObject cancelPreviousPerformRequestsWithTarget:self];//可以胜利取消全体。

[[self class] cancelPreviousPerformRequestsWithTarget:self];//可以胜利取消全体。

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