Storyboard 登录屏以及注销时处理数据清除的最佳实践

在 appDelegate.m 里的 didFinishLaunchingWithOptions

//authenticatedUser: 检查 NSUserDefaults 里的用户证书，如果存在就根据它设置导航流程

if (authenticatedUser) 
{
    self.window.rootViewController = [[UIStoryboard storyboardWithName:@"Main" bundle:[NSBundle mainBundle]] instantiateInitialViewController];        
}
else
{
    UIViewController* rootController = [[UIStoryboard storyboardWithName:@"Main" bundle:[NSBundle mainBundle]] instantiateViewControllerWithIdentifier:@"LoginViewController"];
    UINavigationController* navigation = [[UINavigationController alloc] initWithRootViewController:rootController];

    self.window.rootViewController = navigation;
}

在 SignUpViewController.m 文件

- (IBAction)actionSignup:(id)sender
{
    AppDelegate *appDelegateTemp = [[UIApplication sharedApplication]delegate];

    appDelegateTemp.window.rootViewController = [[UIStoryboard storyboardWithName:@"Main" bundle:[NSBundle mainBundle]] instantiateInitialViewController];
}

在 MyTabThreeViewController.m 文件

- (IBAction)actionLogout:(id)sender {

    // 从 NSUserDefaults 中删除用户证书，以及其他用户相关数据

    AppDelegate *appDelegateTemp = [[UIApplication sharedApplication]delegate];

    UIViewController* rootController = [[UIStoryboard storyboardWithName:@"Main" bundle:[NSBundle mainBundle]] instantiateViewControllerWithIdentifier:@"LoginViewController"];

    UINavigationController* navigation = [[UINavigationController alloc] initWithRootViewController:rootController];
    appDelegateTemp.window.rootViewController = navigation;

}