Question

通常我们从一些UIViewController对象调用self.presentViewController（...），但是如何在一个不是UIViewController的辅助类中从类类型（静态）函数中显示一个新的视图控制器。

Answer 1

您可以将helper类中的viewController显示为navigationcontroller的根视图控制器

UIStoryboard *storyBoard = [UIStoryboard storyboardWithName:@"Main" bundle:[NSBundle mainBundle]];

UINavigationController *controller = (UINavigationController*)[storyBoard
                                                               instantiateViewControllerWithIdentifier: @"RootNavigationController"]; //set storyboard ID to your root navigationController.

YourViewController *vc = [storyBoard instantiateViewControllerWithIdentifier:@"YourViewController"]; // //set storyboard ID to viewController.
[controller setViewControllers:[NSArray arrayWithObject:vc] animated:YES];
AppDelegate *appDelegate = (AppDelegate *)[[UIApplication sharedApplication] delegate];
appDelegate.window.rootViewController=controller;

Answer 2

Mayank Jain在快速4中的回答：

var storyBoard = UIStoryboard(name: "Main", bundle: Bundle.main)
var controller = storyBoard.instantiateViewController(withIdentifier: "RootNavigationController") as? UINavigationController
//set storyboard ID to your root navigationController.
var vc = storyBoard.instantiateViewController(withIdentifier: "YourViewController") as? YourViewController
// //set storyboard ID to viewController.
controller?.setViewControllers([vc], animated: true)
var appDelegate = UIApplication.shared.delegate as? AppDelegate
appDelegate?.window?.rootViewController = controller

Answer 3

直接不可能，您总是需要一个视图控制器/导航控制器实例。但是有一些可能的工作。

这取决于要求，您希望如何使用它。一些建议 -

应用程序委托的导航控制器随处可访问，您可以使用它。
```
  YourAppDelegate *delegate = (YourAppDelegate *) [UIApplication sharedApplication].delegate;
```
现在您可以使用 - delegate.window.rootViewController.navigationController

在辅助方法实例中，从您调用它的位置传递导航控制器的实例。有点像 -

+(void)myHelperMethodWithNavigationController:(UINavigationController*)navController {
  -------
  [navController pushViewController:yourNewCreatedController animated:YES];
 }

从某个视图控制器调用它时

-

[MyHelperClass myHelperMethodWithNavigationController:self.navigationController];

如何从非ViewController帮助器类中显示ViewController？

3 个答案: