我一直在尝试完成验证后执行转场，但是一旦我从情节提要中设置转场，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。我试过这个，这个，这个但是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（意味着完成按钮只有在通过验证方法之后才启用，并且我能够注册用户进行解析）。我相信我使用了正确的方法（应该执行segue 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。谢谢你。
SignUpViewController.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;
注册视图控制器.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，我看到的日志
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 这种方法是否可见
我看到的日志是否通过注册过程 2013-09-06 01:22:20.117 nsnotification 工作正常 2013-09-06 01:22:20.120 确实 usernamefield 成为第一响应者 2013-09-06 01:22： 27.701 已启用完成按钮 2013-09-06 01:22:28.094 已启用完成按钮 2013-09-06 01:22:30.196 此方法是否可见