ios 如何将方法调用延迟 1 秒？
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How can I delay a method call for 1 second?
提问by Thanks
Is there an easy way delay a method call for 1 second?
有没有一种简单的方法将方法调用延迟 1 秒？
I have a UIImageViewthat reacts on a touch event. When the touch is detected, some animations happen in the app. After one second, I want to call another method. In this case, I can't use the animationDidStopselector.
我有一个UIImageView对触摸事件做出反应的。当检测到触摸时，应用程序中会发生一些动画。一秒钟后，我想调用另一种方法。在这种情况下，我不能使用animationDidStop选择器。
回答by Jim
回答by mcfedr
You could also use a block
您也可以使用块
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, 1 * NSEC_PER_SEC), dispatch_get_main_queue(), ^{
[object method];
});
Most of time you will want to use dispatch_get_main_queue, although if there is no UI in the method you could use a global queue.
大多数时候你会想要使用 dispatch_get_main_queue ，尽管如果方法中没有 UI 你可以使用全局 queue。
Edit:
编辑：
Swift 3 version:
斯威夫特 3 版本：
DispatchQueue.main.asyncAfter(deadline: .now() + 1) {
object.method()
}
Equally, DispatchQueue.global().asyncAfter(...might also be a good option.
同样，DispatchQueue.global().asyncAfter(...也可能是一个不错的选择。
回答by Milianoo
Best way to do is :
最好的方法是：
[self performSelector:@selector(YourFunctionName)
withObject:(can be Self or Object from other Classes)
afterDelay:(Time Of Delay)];
you can also pass nil as withObject parameter.
您也可以将 nil 作为 withObject 参数传递。
example :
例子 ：
[self performSelector:@selector(subscribe) withObject:self afterDelay:3.0 ];
回答by Alex Cio
There are already a lot of answers and they are all correct. In case you want to use the dispatch_afteryou should be looking for the snippet which is included inside the Code Snippet Libraryat the right bottom (where you can select the UIelements).
已经有很多答案了，而且都是正确的。如果您想使用 ，dispatch_after您应该寻找包含在Code Snippet Library右下角（您可以选择UI元素的位置）内的代码段。
So you just need to call this snippet by writing dispatchin code:
所以你只需要通过在代码中编写dispatch来调用这个片段：
回答by Nimit Parekh
You can use the perform selector for after the 0.1 sec delay method is call for that following code to do this.
您可以在调用 0.1 秒延迟方法后使用执行选择器来执行此操作。
[self performSelector:@selector(InsertView) withObject:nil afterDelay:0.1];
回答by Geri Borbás
You can also:
你也可以：
[UIView animateWithDuration:1.0
animations:^{ self.view.alpha = 1.1; /* Some fake chages */ }
completion:^(BOOL finished)
{
NSLog(@"A second lapsed.");
}];
This case you have to fake some changes to some view to get the animation work. It is hacky indeed, but I love the block based stuff. Or wrap up @mcfedr answer below.
在这种情况下，您必须对某些视图进行一些更改才能使动画正常工作。它确实很hacky，但我喜欢基于块的东西。或者在下面结束@mcfedr 的回答。
waitFor(1.0, ^
{
NSLog(@"A second lapsed");
});
typedef void (^WaitCompletionBlock)();
void waitFor(NSTimeInterval duration, WaitCompletionBlock completion)
{
dispatch_after(dispatch_time(DISPATCH_TIME_NOW, duration * NSEC_PER_SEC),
dispatch_get_main_queue(), ^
{ completion(); });
}
回答by Nitesh
You can do this
你可以这样做
[self performSelector:@selector(MethodToExecute) withObject:nil afterDelay:1.0 ];
回答by Salman Ghumsani
Swift 2.x
斯威夫特 2.x
let delayTime = dispatch_time(DISPATCH_TIME_NOW, Int64(1 * Double(NSEC_PER_SEC)))
dispatch_after(delayTime, dispatch_get_main_queue()) {
print("do some work")
}
Swift 3.x --&-- Swift 4
斯威夫特 3.x ---&--- 斯威夫特 4
DispatchQueue.main.asyncAfter(deadline: .now() + 1.0) {
print("do some work")
}
or pass a escaping closure
或通过 escaping closure
func delay(seconds: Double, completion: @escaping()-> Void) {
DispatchQueue.main.asyncAfter(deadline: .now() + seconds, execute: completion)
}
回答by Kevin ABRIOUX
There is a Swift 3 solution from the checked solution :
检查的解决方案中有一个 Swift 3 解决方案：
self.perform(#selector(self.targetMethod), with: self, afterDelay: 1.0)
And there is the method
还有方法
@objc fileprivate func targetMethod(){
}
回答by Sujeet Shrivastav
Use in Swift 3
在 Swift 3 中使用
perform(<Selector>, with: <object>, afterDelay: <Time in Seconds>)
