如何延迟进行瞄准 [英] How to Perform Segue With Delay

问题描述

在我的故事板中，我有一个视图作为启动画面。在这个视图中，我已经有一个像打开应用程序的按钮，它打开菜单视图，带有模态segue。但我也希望屏幕自动执行segue，就像2秒钟后出现一样。

In my storyboard, I have a view as a splash screen. In this view, I already have a button like "Open Application" that is opening the menu view with a modal segue. But I also want screen to perform segue automatically, like after 2 seconds view appears.

这里的一些代码：

- (void)viewDidAppear:(BOOL)animated
{
    [self performSegueWithIdentifier:@"splashScreenSegue" sender:self];
}

如您所见，我已经使用了performSegueWithIdentifier，但它立即执行。有没有办法让它延迟？

As you can see, I already use performSegueWithIdentifier but it performs immediately. Is there a method to make it delay?

提前致谢。

推荐答案

你可以使用GCD的 dispatch_after 在视图出现后2秒执行你的segue代码，例如：

You can use GCD's dispatch_after to execute your segue code 2 seconds after the view appears, e.x:

- (void)viewDidAppear:(BOOL)animated 
{
    [super viewDidAppear:animated];

    double delayInSeconds = 2.0;
    dispatch_time_t popTime = dispatch_time(DISPATCH_TIME_NOW, (int64_t)(delayInSeconds * NSEC_PER_SEC));
    dispatch_after(popTime, dispatch_get_main_queue(), ^(void){
        [self performSegueWithIdentifier:@"splashScreenSegue" sender:self];
    });
}

此外，请确保在重写UIViewController时记得调用super实现生命周期方法。

Additionally, please make sure that you remember to call the super implementation when overriding UIViewController's life cycle methods.

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