ios - Objective-C:其 View 不在窗口层次结构中

Question

我有这段代码可以工作，所以一旦我按下按钮， Storyboard中的 View 就会发生变化:

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
ViewController *viewController = (ViewController *)[storyboard instantiateViewControllerWithIdentifier:@"view1"];
[self presentViewController:viewController animated:YES completion:nil];

这段代码有效，但是当我再次使用它来改回我原来的 View 时:

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
ViewController *viewController = (ViewController *)[storyboard instantiateViewControllerWithIdentifier:@"view2"];
[self presentViewController:viewController animated:YES completion:nil];

它不起作用，我收到此错误:

Warning: Attempt to present <UIViewController: 0x863ad30> on <UITabBarController: 0x86309b0> whose view is not in the window hierarchy!

标识已设置，但我不是 viewdidload 中的函数，所以我不知道如何解决这个问题。

有人可以帮忙吗？

Answer 1

试试这个，

第一种方法

-(IBAction)signin:(id)sender
{
    UIStoryboard *sb = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
    UIViewController *vc = [sb instantiateViewControllerWithIdentifier:@"viewController"];
    [[[[UIApplication sharedApplication] delegate] window] setRootViewController:vc];

}

第二种方法(返回上一个 View )

- (IBAction)signout:(id)sender
{

    UIStoryboard *sb = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
    UIViewController *vc = [sb instantiateViewControllerWithIdentifier:@"parentViewController"];
    [[[[UIApplication sharedApplication] delegate] window] setRootViewController:vc];

}