Question

我正在使用登录功能在app上工作。我想要做的是登录后标签显示用户名。

这是我的代码：

#import "ViewController.h"

@interface ViewController ()

@property (strong, nonatomic) IBOutlet UITextField *userNameTextField;

@property (strong, nonatomic) IBOutlet UITextField *passwordTextField;

@end


@implementation ViewController

- (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)Login:(id)sender {


    if ([_userNameTextField.text isEqualToString:@""] || [_passwordTextField.text isEqualToString:@""]) {
        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"alert" message:@"Please Fill all the field" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
        [alert show];
        return;
    }

    NSString *strURL = [NSString stringWithFormat:@"http://192.168.1.11:8888/swift/login.php?userName=%@&password=%@",_userNameTextField.text, _passwordTextField.text];

    NSData *dataURL = [NSData dataWithContentsOfURL:[NSURL URLWithString:strURL]];

    NSString *strResult = [[NSString alloc] initWithData:dataURL encoding:NSUTF8StringEncoding];

    if ([strResult isEqualToString:@"1"])
    {

        NSString *username = _userNameTextField.text;

        UILabel *myLabel = (UILabel *)[self.view viewWithTag:100];
        myLabel.text = [NSString stringWithFormat:@" Label %@",username];


        UIStoryboard *sb = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
        UIViewController *vc = [sb instantiateViewControllerWithIdentifier:@"logedIn"];
        vc.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
        [self presentViewController:vc animated:YES completion:NULL];



    }

    else if ([strResult isEqualToString:@"0"])
    {

        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"alert" message:@"Wrong username / password" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
        [alert show];


        return;
    }

    else {

        UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"alert" message:@"Server Error" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
        [alert show];

        return;
    }
}

@end

这是我的故事板的图像

在图片中，您会看到我第一次在左下角看到。第二个屏幕位于右上角。两者都有类ViewController

我正在使用xcode 7.0

Answer 1

你有2个不同的 ViewController个实例，这意味着第一个更改的UITextField将不会显示在第二个实例中。

你需要有一个对象（让我们称之为 Model ），它将保存数据并按需更改。

无论如何，请将您的体系结构更改为拥有Model图层，以保存您的数据。

如果你想让事情在这里具有特定的作用但是做法不好，请在NSString中创建AppDelegate并在更改后设置数据。并根据需要从那里获取数据。

但是，将您的架构更改为Model-View-Controller

Answer 2

在.h中设置标签的属性，并将其链接到故事板上。

@property (nonatomic, strong) IBOutlet UILabel *label;

然后，在展示新的视图控制器之前，您只需设置该标签的文本。

UIStoryboard *sb = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
UIViewController *vc = [sb instantiateViewControllerWithIdentifier:@"logedIn"];
vc.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
vc.label.text = [NSString stringWithFormat:@" Label %@",username];
[self presentViewController:vc animated:YES completion:NULL];

我无法通过标记目标c更改标签文本

2 个答案: