IOS: several methods of delayed execution (sleep), ios latency

IOS: several methods of delayed execution (sleep), ios latency

1. The most direct method:

 

[Self defined mselector: @ selector (deleyMethod) withObject: nil afterDelay: 1.0];

This method must be executed in the main thread; otherwise, it is invalid. Is a non-blocking execution method, and the method for canceling execution is not found at the moment.

Disadvantage: Write a method for the delay each time.

 

2. UseNSTread

 

[NSThread sleepForTimeInterval: 0.06];

This method can be executed in both the main thread and sub-thread. It is a blocking execution method. The Builder puts it in the sub-thread to avoid getting stuck on the interface. The method for canceling the execution is not found.

 

3. Use GCD.

　　Double delayInSeconds = 2.0;

Dispatch_time_t popTime = dispatch_time (DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC );

Dispatch_after (popTime, dispatch_get_main_queue (), ^ (void ){

// Code to be executed on the main queue after delay

});

 

In this way, you can select the thread to execute in the parameter. Is a non-blocking execution method, and the method for canceling the execution is not found.

 

4. Timer: NSTimer

 

[NSTimer scheduledTimerWithTimeInterval: 1.0f target: self selector: @ selector (delayMethod) userInfo: nil repeats: NO];

This method must be executed in the main thread; otherwise, it is invalid. Is a non-blocking execution method. You can use the NSTimer class-(void) invalidate; to cancel the execution.

 

5. Use NSOperationQueue to execute the following main loop in the application:

<Span style = "background-color: rgb (255,255,255);"> <span style = "color: #000000;"> [[NSOperationQueue mainQueue] addOperationWithBlock: aBlock]; </span>

This is equivalent to calling mongomselector: with afterDelay of 0.0f.

 

6. It may be a bad method. Use the completion parameter of animation.

 

[UIView animateWithDuration: 0.0 delay: 5.0 options: UIViewAnimationOptionAllowUserInteraction animations: ^ {

} Completion: ^ (BOOL finished ){

// Do stuff here

}];