iphone - 如何显示登录和关闭设置 - Storyboard

Question

我想弄清楚如何从注销按钮显示登录(模态视图 Controller )并从登录下方自动关闭设置(模态视图 Controller )。您可能会看到 Storyboard布局:

http://cl.ly/2B3h0T130S1K1026201N

我试图将此代码添加到 SettingsViewController.m 的注销方法中

- (IBAction)logoutAccount {

      [self dismissModalViewControllerAnimated:YES];

      UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
      UIViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@"LoginViewController"];
      [vc setModalPresentationStyle:UIModalPresentationFullScreen];

      [self presentModalViewController:vc animated:YES]; 

} 

问题是当我点击注销时它强制我的应用程序卡住。有人知道它有什么问题吗？任何建议表示赞赏。

Answer 1

用户再次登录后，你希望应用在什么位置？假设您希望应用位于设置按钮所在的 View Controller 中(从 Storyboard 中看起来就是这样)。

然后那个vc(导航 Controller 中的根vc)可以这样做:

- (void)viewDidAppear:(BOOL)animated {

    if (/*login is needed*/) {
        UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"MainStoryboard" bundle:nil];
        UIViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@"LoginViewController"];
        [vc setModalPresentationStyle:UIModalPresentationFullScreen];

        [self presentModalViewController:vc animated:YES]; 
    } else {
        // normal view did appear logic
    }
}

注销按钮现在可以做到这一点:

- (IBAction)logoutButtonPressed:(id)sender {
    [self.navigationController popToRootViewControllerAnimated:NO];
}