Question

应该有一个包含全名，用户名，密码，电子邮件和注册按钮的注册页面。当我们点击注册按钮时，我们转到登录页面，它使用NSUserDefaults验证我们在注册页面中创建的用户名和密码。现在，如果我们提供正确的凭据，那么它应该重定向到注销页面，当我们下次打开应用程序时，它应该直接重定向到注销页面。数据应使用NSUserDefaults在本地存储（值应以字符串格式存储）。

登录视图控制器.h

#import <UIKit/UIKit.h>

@interface ViewController2 : UIViewController
@property(strong, nonatomic)NSString *dataString;
@property(strong, nonatomic)NSString *dataString2;

@property (strong, nonatomic) IBOutlet UILabel *lblOutput;
@property (strong, nonatomic) IBOutlet UITextField *inputTxt1;
@property (strong, nonatomic) IBOutlet UITextField *inputTxt2;
- (IBAction)btnAction:(id)sender;

@end

登录视图控制器.m

 #import "ViewController2.h"

@interface ViewController2 ()

@end

@implementation ViewController2

- (void)viewDidLoad {
    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    NSString *firstName = [defaults objectForKey:@"firstName"];
    NSString *lastName = [defaults objectForKey:@"lastname"];

    firstName = _inputTxt1.text;
    lastName = _inputTxt2.text;

    [super viewDidLoad];
    NSLog(@"%@",self.dataString);
    NSLog(@"%@",self.dataString2);

    self.navigationItem.title = @"Login Page";
}

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


- (IBAction)btnAction:(id)sender {
    NSString *firstName = [_inputTxt1 text];
    NSString *lastName  = [_inputTxt2 text];

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

    [defaults setObject:firstName forKey:@"firstName"];
    [defaults setObject:lastName forKey:@"lastname"];
    [defaults synchronize];


//    [Defaults setObject:@"Eezy"forKey:@"iOS"];
    NSLog(@"%@",[defaults stringForKey:@"firstName"]);
    NSLog(@"%@",[defaults stringForKey:@"lastName"]);
    if ([self.dataString isEqualToString:[defaults objectForKey:@"firstName"]] && [self.dataString2 isEqualToString:[defaults objectForKey:@"lastName"]])
    {

        NSLog(@"goog");
        [self performSegueWithIdentifier:@"segueToNextPage2" sender:self];
    }
    else
    {
        UIAlertView *alert = [[UIAlertView alloc]initWithTitle:@"Hey Listen" message:@"Wrong User Name or Password" delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil, nil];

        [alert show];
    }
}

@end

问题是我已经从注册页面传递了值，但是当我将它存储在NSUserDefault中时，它存储了用户名的值，但是在密码的情况下，它显示为空值。

Answer 1

保存登录值，您可以使用

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

// saving an NSString
[prefs setObject:txtUsername.text forKey:@"userName"];
[prefs setObject:txtPassword.text forKey:@"password"];

 [prefs synchronize];

FOR RETRIEVING Values

NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];

// getting an NSString
NSString *savedUsername = [prefs stringForKey:@"userName"];
NSString *savedPassword = [prefs stringForKey:@"password"];

注销：

[[NSUserDefaults standardUserDefaults] removeObjectForKey:@"Your Key"];

Answer 2

这是我得到的解决方案： -

步骤1：在登录页面中定义一个bool变量，并在单击登录按钮

时将其值设置为true

- (IBAction)btnAction:(id)sender {
NSUserDefaults *prefs = [NSUserDefaults standardUserDefaults];
[prefs setBool:YES forKey:@"registered"];
    [prefs synchronize];
}

步骤2.在身份检查器中创建一个storyBoard作为“UITabBarController”。请记住，这将是您要去的页面。

步骤3.在@implemention下面的AppDelegate.h文件中编写以下代码： -

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    if ([[NSUserDefaults standardUserDefaults] boolForKey:@"registered"]) {

        UITabBarController *controller = [self.window.rootViewController.storyboard instantiateViewControllerWithIdentifier:@"UITabBarController"];
        self.window.rootViewController = controller;
    }
    return YES;
}

这很简单。

Answer 3

将详细信息保存在注册页面的NSUserDefaults中。同时在NSUserDefaults中输入以检查用户是否登录。

[[NSUserDefaults standardUserDefaults]setValue:@"YES" forKey:@"isLoggedIn"];

在AppDelegate的didFinishLaunching方法中，根据initialViewController键值更改isLoggedIn，例如

if ([[[NSUserDefaults standardUserDefaults]valueForKey:@"isLoggedIn"] isEqualToString:@"YES"])
    {
        // redirect to logout screen
    }
    else
    {
        //show login or register screen
    }

使用Xcode在iOS中注册登录注销应用程序（NSUserDefaults）

3 个答案: