ios - 完成按钮开始启用并在开始输入用户名后自行禁用，跳过验证方法

Question

我一直在尝试在验证后执行 segue，但是一旦我从 Storyboard 中设置 segue，编译器就会忽略验证和-(BOOL)shouldPerformSegueWithIdentifier:(NSString *)identifier sender:(id)sender
方法并从一开始就启用完成按钮。我试过 this , this , this但我相信我错过了一个关键点。在连接 segue 之前，我能够验证我的注册并且它工作得很好(这意味着完成按钮仅在通过验证方法后才会启用并且我能够注册用户进行解析)。我相信我使用的是正确的方法(shouldperformsegue 方法)但参数错误。因此，如果有人可以帮助我了解我做错了什么，我将不胜感激。谢谢。

注册 View Controller .h

#import <UIKit/UIKit.h>


@interface SignUpViewController : UIViewController<UITextFieldDelegate>
@property (weak, nonatomic) IBOutlet UIBarButtonItem *doneButton;
@property (weak, nonatomic) IBOutlet UITextField *userNameField;
@property (weak, nonatomic) IBOutlet UITextField *passwordField;
@property (weak, nonatomic) IBOutlet UITextField *reEnterPasswordField;
- (IBAction)done:(id)sender;
- (IBAction)cancel:(id)sender;

SignUpViewController.m

#import "SignUpViewController.h"
#import <Parse/Parse.h>
#import "ActivityView.h"
#import "ProfileViewController.h"

@interface SignUpViewController ()
- (void)textInputChanged:(NSNotification *)note;
-(void)processFieldEntries;
- (BOOL)shouldEnableDoneButton;
@end

@implementation SignUpViewController

@synthesize doneButton = _doneButton;
@synthesize userNameField = _userNameField;
@synthesize passwordField = _passwordField;
@synthesize reEnterPasswordField = _reEnterPasswordField;


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

- (void)viewDidLoad
{
    [super viewDidLoad];

        [[NSNotificationCenter defaultCenter ]addObserver:self selector:@selector(textInputChanged:) name:  UITextFieldTextDidChangeNotification object:_userNameField];
        [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(textInputChanged:) name:UITextFieldTextDidChangeNotification object:_passwordField];
        [[NSNotificationCenter defaultCenter]addObserver:self selector:@selector(textInputChanged:) name:UITextFieldTextDidChangeNotification object:_reEnterPasswordField];

    _doneButton.enabled = YES;
    NSLog(@"nsnotification is working fine");

}
-(void)viewWillAppear:(BOOL)animated
{
    [_userNameField becomeFirstResponder];
    [super viewWillAppear:animated];
    NSLog(@"indeed usernamefield became a first responder");

}
- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
}
-(BOOL)textFieldShouldReturn:(UITextField *)textField
{
    if (textField == _userNameField ) {
        [_userNameField becomeFirstResponder];
    }
    if (textField == _passwordField) {
        [_passwordField becomeFirstResponder];
    }
    if (textField == _reEnterPasswordField)
    {
        [_reEnterPasswordField becomeFirstResponder];
    }
    NSLog(@"keyboard action works fine ");
    return YES;
}
-(BOOL)shouldEnableDoneButton
{
    BOOL enableDoneButton = NO;

    if (_userNameField.text != nil &&
        _userNameField.text.length > 0 &&
        _passwordField.text != nil &&
        _passwordField.text.length > 0 &&
        _reEnterPasswordField.text != nil &&
        _reEnterPasswordField.text.length > 0)
    {
        enableDoneButton = YES;
        NSLog(@"done button enabled");
    }
    return enableDoneButton;

}
-(void)textInputChanged:(NSNotification *)note
{
    _doneButton.enabled = [self shouldEnableDoneButton];

}
- (IBAction)done:(id)sender {
    [_userNameField resignFirstResponder];
    [_passwordField resignFirstResponder];
    [_passwordField resignFirstResponder];
    [self processFieldEntries];

}

- (IBAction)cancel:(id)sender
{
    [self.presentingViewController dismissViewControllerAnimated:YES completion:nil];

}
-(void)processFieldEntries
{
    // Check that we have a non-zero username and passwords.
    // Compare password and passwordAgain for equality
    // Throw up a dialog that tells them what they did wrong if they did it wrong.

    NSString *username = _userNameField.text;
    NSString *password = _passwordField.text;
    NSString *passwordAgain = _reEnterPasswordField.text;
    NSString *errorText = @"Please ";
    NSString *usernameBlankText = @"enter a username";
    NSString *passwordBlankText = @"enter a password";
    NSString *joinText = @", and ";
    NSString *passwordMismatchText = @"enter the same password twice";

    BOOL textError = NO;
    NSLog(@"validation begins here");

    // Messaging nil will return 0, so these checks implicitly check for nil text.

    if (username.length == 0 || password.length == 0 || passwordAgain.length == 0) {
        textError = YES;
    }
    if (passwordAgain.length == 0) {
        [_reEnterPasswordField becomeFirstResponder];
    }
    if (username.length == 0) {
        [_userNameField becomeFirstResponder];
    }
    if (password.length == 0)
    {
        [_passwordField becomeFirstResponder];
    }
    if (username.length == 0) {
        errorText = [errorText stringByAppendingString:usernameBlankText];
    }
    if (password.length == 0 || passwordAgain.length == 0) {
        if (username.length == 0) {
            // We need some joining text in the error
            errorText = [errorText stringByAppendingString:joinText];
        }
        errorText = [errorText stringByAppendingString:passwordBlankText];
    }else if ([password compare:passwordAgain] != NSOrderedSame)
    {
        // We have non-zero strings.
        // Check for equal password strings.
        textError = YES;
        errorText = [errorText stringByAppendingString:passwordMismatchText];
        [_passwordField becomeFirstResponder];
    }
    if (textError) {
        UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:errorText message:nil delegate:self cancelButtonTitle:nil otherButtonTitles:@"OK", nil];
        [alertView show];
        return;
    }
    NSLog(@"validation works just fine");

    // Everything looks good; try to log in.
    // Disable the done button for now.
    _doneButton.enabled = NO;
    ActivityView *activityCircle = [[ActivityView alloc] initWithFrame:CGRectMake(0.f, 0.f, self.view.frame.size.width, self.view.frame.size.height)];
    UILabel *label = activityCircle.label;
    label.text = @"Signing You Up";
    label.font = [UIFont boldSystemFontOfSize:20.f];
    [activityCircle.activityIndicator startAnimating];
    [activityCircle layoutSubviews];

    [self.view addSubview:activityCircle];
    NSLog(@"activity view works just fine");

    //parse registeration
    // Call into an object somewhere that has code for setting up a user.
    // The app delegate cares about this, but so do a lot of other objects.
    // For now, do this inline.

    PFUser *user = [PFUser user];
    user.username = username;
    user.password = password;
    [user signUpInBackgroundWithBlock:^(BOOL succeeded, NSError *error) {
        if (error) {
            UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:[[error userInfo] objectForKey:@"error"] message:nil delegate:self cancelButtonTitle:nil otherButtonTitles:@"Ok", nil];
            [alertView show];
            _doneButton.enabled = [self shouldEnableDoneButton];
            [activityCircle.activityIndicator stopAnimating];
            [activityCircle removeFromSuperview];
            // Bring the keyboard back up, because they'll probably need to change something.
            [_userNameField becomeFirstResponder];
            return;
        }
        // Success!
        [activityCircle.activityIndicator stopAnimating];
        [activityCircle removeFromSuperview];
        //add the next screen here
    }];
    NSLog(@"user signedup just fine");
    //now pass the view from sign up to profile view
}
/*
 //this one didnt work
-(void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender
{

    ProfileViewController *myProfileView = [segue destinationViewController];
    if (_doneButton.enabled == YES) {
           [myProfileView performSegueWithIdentifier:@"SignUpSegue" sender:_doneButton];
    }


}
 */
-(BOOL)shouldPerformSegueWithIdentifier:(NSString *)identifier sender:(id)sender
{   NSLog(@"is this method visible");
    if (_doneButton.enabled == YES) {
        [self performSegueWithIdentifier:@"SignUpSegue" sender:_doneButton];
    }

return NO;

}

 @end

如果我立即单击完成按钮，我会看到日志

2013-09-06 01:20:07.148 nsnotification 工作正常2013-09-06 01:20:07.155 确实 usernamefield 成为了第一响应者2013-09-06 01:20:11.290 这个方法是否可见

我在注册过程中看到的日志2013-09-06 01:22:20.117 nsnotification 工作正常2013-09-06 01:22:20.120 确实 usernamefield 成为了第一响应者2013-09-06 01:22:27.701 已启用完成按钮2013-09-06 01:22:28.094 启用完成按钮2013-09-06 01:22:30.196 这个方法可见吗

Answer 1

您的完成按钮验证有误。您没有检查密码重复是否与第一个密码相同。

此外，请确保在 Storyboard 中默认禁用完成按钮。只明确启用它。