IOS 关于取消延迟执行函数的种种。performSelector与cancelPreviousPerformRequestsWithTarget

http://blog.csdn.net/samuelltk/article/details/8994313

 

 

[置顶] IOS 关于取消延迟执行函数的种种。performSelector与cancelPreviousPerformRequestsWithTarget

分类: IOS
[cpp]  view plain copy
  1. @interface NSObject (NSDelayedPerforming)  
  2.   
  3. - (void)performSelector:(SEL)aSelector withObject:(id)anArgument afterDelay:(NSTimeInterval)delay inModes:(NSArray *)modes;  
  4. - (void)performSelector:(SEL)aSelector withObject:(id)anArgument afterDelay:(NSTimeInterval)delay;  
  5. + (void)cancelPreviousPerformRequestsWithTarget:(id)aTarget selector:(SEL)aSelector object:(id)anArgument;  
  6. + (void)cancelPreviousPerformRequestsWithTarget:(id)aTarget;  
  7.   
  8. @end  

 

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一致,否则不能取消成功。
开始延迟执行:

 

[cpp]  view plain copy
  1. [self performSelector:@selector(didRuninCurrModel:) withObject:[NSNumber numberWithBool:YES] afterDelay:3.0f];  
  2.   
  3. [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:

 

 

[cpp]  view plain copy
  1. [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(didRuninCurrModel:) object:[NSNumber numberWithBool:YES]];//可以取消成功。  
  2.   
  3. [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(didRuninCurrModel:) object:[NSNumber numberWithBool:NO]];//不能取消成功。参数不匹配  
  4.   
  5. [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(didRuninCurrModel:) object:nil];//不能取消成功。参数不匹配  
  6.   
  7. [NSObject cancelPreviousPerformRequestsWithTarget:self selector:@selector(didRuninCurrModelNoArgument) object:nil];//可以成功取消  
  8.   
  9. [NSObject cancelPreviousPerformRequestsWithTarget:self];//可以成功取消全部。  
  10. [[self class] cancelPreviousPerformRequestsWithTarget:self];//可以成功取消全部。  

代码下载地址:http://download.csdn.net/detail/samuelltk/5481327

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