我正在使用Storyboard构建一个iOS应用程序。根视图控制器是一个标签栏控制器。我正在创建登录/注销过程,它基本上工作正常,但我有一些问题。我需要知道最好的方法来设置这一切。

我想做到以下几点:

在应用程序第一次启动时显示登录屏幕。当他们登录时,转到标签栏控制器的第一个标签。 任何时候他们启动应用程序之后,检查他们是否登录,并直接跳到根标签栏控制器的第一个标签。 当他们手动单击登出按钮时,显示登录屏幕,并清除视图控制器中的所有数据。

到目前为止,我所做的是将根视图控制器设置为标签栏控制器,并创建了一个自定义segue到Login视图控制器。在我的标签栏控制器类中,我检查他们是否在viewDidAppear方法中登录,并执行segue: [self performSegueWithIdentifier:@"pushLogin" sender:self];

我还设置了一个通知,当注销操作需要执行:[[NSNotificationCenter defaultCenter] addObserver:自我选择器:@选择器(logoutAccount)名称:@“logoutAccount”对象:nil];

注销后,我从Keychain中清除凭据,运行[self setSelectedIndex:0],并执行segue再次显示登录视图控制器。

这一切都很好,但我想知道:这个逻辑应该在AppDelegate中吗?我还有两个问题:

他们第一次启动应用程序时,标签栏控制器在segue执行之前简要显示。我已经尝试移动代码到viewWillAppear,但segue不会工作那么早。 注销时,所有数据仍在所有视图控制器中。如果他们登录到一个新帐户,旧帐户数据仍然显示,直到他们刷新。我需要一种方法来清除这很容易登出。

我愿意重新修改。我考虑过让登录屏幕成为根视图控制器,或者在AppDelegate中创建一个导航控制器来处理所有事情…我只是不确定目前最好的方法是什么。


当前回答

不建议在应用委托中这样做。AppDelegate管理与启动、挂起、终止等相关的应用生命周期。我建议从viewDidAppear中的初始视图控制器开始。你可以自我。presentViewController和self。从登录视图控制器中去遣散viewcontroller。在NSUserDefaults中存储一个bool键,以查看它是否第一次启动。

其他回答

在Xcode 7中,你可以有多个故事板。如果您能将Login流保存在一个单独的故事板中会更好。

这可以使用SELECT VIEWCONTROLLER > Editor > Refactor to Storyboard完成

这里是设置一个视图为rootviewcontroller -的Swift版本

    let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
    appDelegate.window!.rootViewController = newRootViewController

    let rootViewController: UIViewController = UIStoryboard(name: "Main", bundle: nil).instantiateViewControllerWithIdentifier("LoginViewController")

在你的appDelegate中。我在你的didFinishLaunchingWithOptions里面

//authenticatedUser: check from NSUserDefaults User credential if its present then set your navigation flow accordingly

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文件中

- (IBAction)actionLogout:(id)sender {

    // Delete User credential from NSUserDefaults and other data related to user

    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;

}

Swift 4版本

didFinishLaunchingWithOptions在app delegate中假设你的初始视图控制器是TabbarController中的signed。

if Auth.auth().currentUser == nil {
        let rootController = UIStoryboard(name: "Main", bundle: Bundle.main).instantiateViewController(withIdentifier: "WelcomeNavigation")
        self.window?.rootViewController = rootController
    }

    return true

在注册视图控制器中:

@IBAction func actionSignup(_ sender: Any) {
let appDelegateTemp = UIApplication.shared.delegate as? AppDelegate
appDelegateTemp?.window?.rootViewController = UIStoryboard(name: "Main", bundle: Bundle.main).instantiateInitialViewController()
}

MyTabThreeViewController

 //Remove user credentials
guard let appDel = UIApplication.shared.delegate as? AppDelegate else { return }
        let rootController = UIStoryboard(name: "Main", bundle: Bundle.main).instantiateViewController(withIdentifier: "WelcomeNavigation")
        appDel.window?.rootViewController = rootController

编辑:添加注销操作。

1. 首先准备app委托文件

AppDelegate.h

#import <UIKit/UIKit.h>

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;
@property (nonatomic) BOOL authenticated;

@end

AppDelegate.m

#import "AppDelegate.h"
#import "User.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    User *userObj = [[User alloc] init];
    self.authenticated = [userObj userAuthenticated];

    return YES;
}

2. 创建一个名为User的类。

User.h

#import <Foundation/Foundation.h>

@interface User : NSObject

- (void)loginWithUsername:(NSString *)username andPassword:(NSString *)password;
- (void)logout;
- (BOOL)userAuthenticated;

@end

User.m

#import "User.h"

@implementation User

- (void)loginWithUsername:(NSString *)username andPassword:(NSString *)password{

    // Validate user here with your implementation
    // and notify the root controller
    [[NSNotificationCenter defaultCenter] postNotificationName:@"loginActionFinished" object:self userInfo:nil];
}

- (void)logout{
    // Here you can delete the account
}

- (BOOL)userAuthenticated {

    // This variable is only for testing
    // Here you have to implement a mechanism to manipulate this
    BOOL auth = NO;

    if (auth) {
        return YES;
    }

    return NO;
}

3.创建一个新的控制器RootViewController,并连接到登录按钮所在的第一个视图。同时添加一个故事板ID: "initialView"。

RootViewController.h

#import <UIKit/UIKit.h>
#import "LoginViewController.h"

@protocol LoginViewProtocol <NSObject>

- (void)dismissAndLoginView;

@end

@interface RootViewController : UIViewController

@property (nonatomic, weak) id <LoginViewProtocol> delegate;
@property (nonatomic, retain) LoginViewController *loginView;


@end

RootViewController.m

#import "RootViewController.h"

@interface RootViewController ()

@end

@implementation RootViewController

@synthesize loginView;

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view, typically from a nib.
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)loginBtnPressed:(id)sender {

    [[NSNotificationCenter defaultCenter] addObserver:self
                                             selector:@selector(loginActionFinished:)
                                                 name:@"loginActionFinished"
                                               object:loginView];

}

#pragma mark - Dismissing Delegate Methods

-(void) loginActionFinished:(NSNotification*)notification {

    AppDelegate *authObj = (AppDelegate*)[[UIApplication sharedApplication] delegate];
    authObj.authenticated = YES;

    [self dismissLoginAndShowProfile];
}

- (void)dismissLoginAndShowProfile {
    [self dismissViewControllerAnimated:NO completion:^{
        UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
        UITabBarController *tabView = [storyboard instantiateViewControllerWithIdentifier:@"profileView"];
        [self presentViewController:tabView animated:YES completion:nil];
    }];


}

@end

4. 创建一个新的控制器LoginViewController,并连接到登录视图。

LoginViewController.h

#import <UIKit/UIKit.h>
#import "User.h"

@interface LoginViewController : UIViewController

LoginViewController。m

#import "LoginViewController.h"
#import "AppDelegate.h"

- (void)viewDidLoad
{
    [super viewDidLoad];
}

- (IBAction)submitBtnPressed:(id)sender {
    User *userObj = [[User alloc] init];

    // Here you can get the data from login form
    // and proceed to authenticate process
    NSString *username = @"username retrieved through login form";
    NSString *password = @"password retrieved through login form";
    [userObj loginWithUsername:username andPassword:password];
}

@end

5. 最后添加一个新的控制器ProfileViewController,并连接到tabViewController中的配置文件视图。

ProfileViewController.h

#import <UIKit/UIKit.h>

@interface ProfileViewController : UIViewController

@end

ProfileViewController.m

#import "ProfileViewController.h"
#import "RootViewController.h"
#import "AppDelegate.h"
#import "User.h"

@interface ProfileViewController ()

@end

@implementation ProfileViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}

- (void)viewDidLoad
{
    [super viewDidLoad];

}

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

    if(![(AppDelegate*)[[UIApplication sharedApplication] delegate] authenticated]) {

        UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];

        RootViewController *initView =  (RootViewController*)[storyboard instantiateViewControllerWithIdentifier:@"initialView"];
        [initView setModalPresentationStyle:UIModalPresentationFullScreen];
        [self presentViewController:initView animated:NO completion:nil];
    } else{
        // proceed with the profile view
    }
}

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}

- (IBAction)logoutAction:(id)sender {

   User *userObj = [[User alloc] init];
   [userObj logout];

   AppDelegate *authObj = (AppDelegate*)[[UIApplication sharedApplication] delegate];
   authObj.authenticated = NO;

   UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];

   RootViewController *initView =  (RootViewController*)[storyboard instantiateViewControllerWithIdentifier:@"initialView"];
   [initView setModalPresentationStyle:UIModalPresentationFullScreen];
   [self presentViewController:initView animated:NO completion:nil];

}

@end

LoginExample是一个提供额外帮助的示例项目。

我用这个来检查第一次发射:

- (NSInteger) checkForFirstLaunch
{
    NSInteger result = 0; //no first launch

    // Get current version ("Bundle Version") from the default Info.plist file
    NSString *currentVersion = (NSString*)[[NSBundle mainBundle] objectForInfoDictionaryKey:@"CFBundleVersion"];
    NSArray *prevStartupVersions = [[NSUserDefaults standardUserDefaults] arrayForKey:@"prevStartupVersions"];
    if (prevStartupVersions == nil)
    {
        // Starting up for first time with NO pre-existing installs (e.g., fresh
        // install of some version)
        [[NSUserDefaults standardUserDefaults] setObject:[NSArray arrayWithObject:currentVersion] forKey:@"prevStartupVersions"];
        result = 1; //first launch of the app
    } else {
        if (![prevStartupVersions containsObject:currentVersion])
        {
            // Starting up for first time with this version of the app. This
            // means a different version of the app was alread installed once
            // and started.
            NSMutableArray *updatedPrevStartVersions = [NSMutableArray arrayWithArray:prevStartupVersions];
            [updatedPrevStartVersions addObject:currentVersion];
            [[NSUserDefaults standardUserDefaults] setObject:updatedPrevStartVersions forKey:@"prevStartupVersions"];
            result = 2; //first launch of this version of the app
        }
    }

    // Save changes to disk
    [[NSUserDefaults standardUserDefaults] synchronize];

    return result;
}

(如果用户删除应用程序并重新安装,则算作第一次启动)

在AppDelegate中,我检查了第一次启动,并创建了一个带有登录屏幕(登录和注册)的导航控制器,我把它放在当前主窗口的顶部:

[self.window makeKeyAndVisible];

if (firstLaunch == 1) {
    UINavigationController *_login = [[UINavigationController alloc] initWithRootViewController:loginController];
    [self.window.rootViewController presentViewController:_login animated:NO completion:nil];
}

因为它在常规视图控制器的顶部它独立于应用的其他部分如果你不再需要它,你可以解散视图控制器。如果用户手动按下按钮,您也可以以这种方式显示视图。

顺便说一句:我保存用户的登录数据是这样的:

KeychainItemWrapper *keychainItem = [[KeychainItemWrapper alloc] initWithIdentifier:@"com.youridentifier" accessGroup:nil];
[keychainItem setObject:password forKey:(__bridge id)(kSecValueData)];
[keychainItem setObject:email forKey:(__bridge id)(kSecAttrAccount)];

对于注销:我从CoreData(太慢)切换到现在使用nsarray和nsdictionary来管理我的数据。注销仅仅意味着清空这些数组和字典。另外,我确保在viewWillAppear中设置我的数据。

就是这样。

创建LoginViewController和TabBarController之后,我们需要分别添加一个StoryboardID作为“LoginViewController”和“TabBarController”。

然后我更喜欢创建Constant结构体:

struct Constants {
    struct StoryboardID {
        static let signInViewController = "SignInViewController"
        static let mainTabBarController = "MainTabBarController"
    }

    struct kUserDefaults {
        static let isSignIn = "isSignIn"
    }
}

在LoginViewController中添加IBAction:

@IBAction func tapSignInButton(_ sender: UIButton) {
    UserDefaults.standard.set(true, forKey: Constants.kUserDefaults.isSignIn)
    Switcher.updateRootViewController()
}

在ProfileViewController中添加IBAction:

@IBAction func tapSignOutButton(_ sender: UIButton) {
    UserDefaults.standard.set(false, forKey: Constants.kUserDefaults.isSignIn)
    Switcher.updateRootViewController()
}

在AppDelegate中添加一行didFinishLaunchingWithOptions代码:

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

    Switcher.updateRootViewController()

    return true
}

最后创建Switcher类:

import UIKit

class Switcher {

    static func updateRootViewController() {

        let status = UserDefaults.standard.bool(forKey: Constants.kUserDefaults.isSignIn)
        var rootViewController : UIViewController?

        #if DEBUG
        print(status)
        #endif

        if (status == true) {
            let mainStoryBoard = UIStoryboard(name: "Main", bundle: nil)
            let mainTabBarController = mainStoryBoard.instantiateViewController(withIdentifier: Constants.StoryboardID.mainTabBarController) as! MainTabBarController
            rootViewController = mainTabBarController
        } else {
            let mainStoryBoard = UIStoryboard(name: "Main", bundle: nil)
            let signInViewController = mainStoryBoard.instantiateViewController(withIdentifier: Constants.StoryboardID.signInViewController) as! SignInViewController
            rootViewController = signInViewController
        }

        let appDelegate = UIApplication.shared.delegate as! AppDelegate
        appDelegate.window?.rootViewController = rootViewController

    }

}

就这些!