Question

我是objective-c的新手，最近开始在Xcode中开发iOS应用程序。我正在制作一个有两个视图控制器的登录应用程序。它看起来像这样：http://imgur.com/W3nxMEG

现在我的问题是我只是在以下情况下才能进入第二个ViewController： 1）填写文本字段 2）密码匹配

这是我写的代码。我无法找到任何控制viewControlled基于某些约束的转换的命令：

(IBAction)loginButton:(id)sender {

BOOL passMatch, emptyUser, emptyPass, emptyrePass;

passMatch = [password isEqualToString:reEnter];

emptyUser = [username isEqualToString:@""];

emptyPass = [password isEqualToString:@""];

emptyrePass = [reEnter isEqualToString:@""];


if (emptyPass || emptyUser || emptyrePass){

    UIAlertView *error=[[UIAlertView alloc] initWithTitle:@"Ooops!" message:@"You must complete all the fields " delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [error show];

}

else{

    passMatch = [password isEqualToString:reEnter];

    if (passMatch){


       UIAlertView *pass=[[UIAlertView alloc] initWithTitle:@"Success!" message:@"Passwords match " delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [pass show];

    } else{

        UIAlertView *error=[[UIAlertView alloc] initWithTitle:@"Ooops!" message:@"Passwords dont match " delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [error show];
    }
}

如果有人能帮我解决这个问题，请感恩。

Answer 1

首先确保您的storyBoard中的UITextField和UIButton与LoginViewController.h

中的某个属性相关联

它看起来像这样：

LoginViewController.h

@interface LoginViewController : UIViewController

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

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

// and so on..

// for your button
@property (strong, nonatomic) IBOutlet UIButton *loginButton;

@end

LoginViewController.m

@implementation LoginViewController


-(IBAction)loginButton:(id)sender 
{

    // you can enable/disable your button here also, by:
    // UIButton *senderButton = (UIButton *)sender;
    // senderButton.enabled = YES/NO;

    // i'm just using .length because i trust numbers more that the @""
    NSString *errorMessage;

if (self.username.text.length == 0)
    errorMessage = @"username is required";

else if (self.password.text.length == 0)
    errorMessage = @"password is required";

else if (self.reEnter.text.length == 0)
    errorMessage = @"please confirm your password";

else if (self.password.text.length == 0 || self.username.text.length == 0 || self.reEnter.text.length == 0)
    errorMessage = @"You must complete all the fields";

if (errorMessage.length > 0)
{
    UIAlertView *error=[[UIAlertView alloc] initWithTitle:@"Ooops!" message:errorMessage delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
    [error show];
}
else
{
    if ([self.username.text isEqual: @"youUsername"] && [self.password.text isEqual: @"youPassword"] && [self.password.text isEqual: self.reEnter.text])
    {
        UIAlertView *pass=[[UIAlertView alloc] initWithTitle:@"Success!" message:@"Login successful" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [pass show];

        //presentYourSecondViewController         
        //[self presentViewController:(UIViewController) animated:(BOOL) completion:nil];
        //[self.navigationController pushViewController:(UIViewController)animated:(BOOL)];
    }
    else
    {
        UIAlertView *error=[[UIAlertView alloc] initWithTitle:@"Ooops!" message:@"Login failed" delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [error show];
    }
}


    /* Your code...


    BOOL passMatch, emptyUser, emptyPass, emptyrePass;

    passMatch = [password isEqualToString:reEnter];

    emptyUser = [username isEqualToString:@""];

    emptyPass = [password isEqualToString:@""];

    emptyrePass = [reEnter isEqualToString:@""];

    if (emptyPass || emptyUser || emptyrePass){

        UIAlertView *error=[[UIAlertView alloc] initWithTitle:@"Ooops!" message:@"You must complete all the fields " delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
        [error show];

    }

    else
    {

        passMatch = [password isEqualToString:reEnter];

        if (passMatch){

            UIAlertView *pass=[[UIAlertView alloc] initWithTitle:@"Success!" message:@"Passwords match " delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
            [pass show];

        } else{

            UIAlertView *error=[[UIAlertView alloc] initWithTitle:@"Ooops!" message:@"Passwords dont match " delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
            [error show];
        }
    }
    */
}

@end

你的情况没有任何问题我刚刚完成它我猜...无论如何希望我帮助你快乐编码欢呼..

控制两个viewControllers之间的转换

1 个答案: