無法隱藏以編程方式創建的UIButton？

Question

LoginController嘗試簡單登錄嘗試 - 如果其成功，則調用setEmail,leftcontroller。

所有我需要做的，當setEmail被調用是隱藏btnLogin並顯示buttonUser並沒有什麼我嘗試工作。 NSLog被調用，EventsController加載使setEmail正在工作 - 它不會隱藏和顯示按鈕。

leftcontroller.h：

@interface LeftController : UIViewController <UIApplicationDelegate> 
{ 
    IBOutlet UIButton *btnLogin; 
    IBOutlet UIButton *buttonUser; 
    NSString *setEmail; 
} 
@property (nonatomic,strong) IBOutlet UIButton *btnLogin; 
@property (nonatomic,strong) IBOutlet UIButton *buttonUser; 

@property(nonatomic,strong) UITableView *tableView; 
@property(nonatomic) NSString *Email; 

//-(void) setEmail : (NSString *) Email; 

@end 

leftcontroller.m：

- (void) setEmail : (NSString *) Email{ 
    [buttonUser setTitle:Email forState:UIControlStateNormal]; 
    //btnLogin.hidden = YES; 
    //buttonUser.hidden = NO; 
    [btnLogin setHidden:YES]; 
    [buttonUser setHidden:NO]; 

    NSLog(@"Set Email Called"); 
    NSLog(@"email: %@", Email); 

    DDMenuController *menuController = (DDMenuController*)((AppDelegate*)[[UIApplication sharedApplication] delegate]).menuController; 
    EventsViewController *controller = [[EventsViewController alloc] init]; 
    UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:controller]; 

     [menuController setRootController:navController animated:YES]; 
} 

-(void)viewDidLoad { 
    [super viewDidLoad]; 

    self.view.backgroundColor = HEXCOLOR(0x000000); 

    btnLogin = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
    btnLogin.frame = CGRectMake(0, 0, 180.f, 48); 
    [btnLogin setTitle:@"Login" forState:UIControlStateNormal]; 
    [btnLogin addTarget:self action:@selector(LoginPressed) 
     forControlEvents:UIControlEventTouchUpInside]; 
    btnLogin.tag=1; 

    btnLogin.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft; 
    [btnLogin setTitleColor: [UIColor whiteColor] forState:UIControlStateNormal]; 
    btnLogin.contentEdgeInsets = UIEdgeInsetsMake(0, 10, 0, 0); 

    UIImage *btnImage = [UIImage imageNamed:@"nav_top.png"]; 
    [btnLogin setBackgroundImage:btnImage forState:UIControlStateNormal]; 
    [self.view addSubview:btnLogin]; 

    buttonUser = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
    buttonUser.frame = CGRectMake(0, 0, 180.f, 48); 
    //[buttonUser setTitle:_Email forState:UIControlStateNormal]; 
    [buttonUser addTarget:self action:@selector(EmailPressed) 
     forControlEvents:UIControlEventTouchUpInside]; 
    buttonUser.contentHorizontalAlignment = UIControlContentHorizontalAlignmentLeft; 
    [buttonUser setTitleColor: [UIColor whiteColor] forState:UIControlStateNormal]; 
    buttonUser.contentEdgeInsets = UIEdgeInsetsMake(0, 10, 0, 0); 

    UIImage *btnImage1 = [UIImage imageNamed:@"nav_top.png"]; 
    [buttonUser setBackgroundImage:btnImage1 forState:UIControlStateNormal]; 
    [self.view addSubview:buttonUser]; 
    buttonUser.hidden = YES; 
} 

Answer 1

此行是犯罪嫌疑人：

btnLogin = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 
// ... 
[self.view addSubview:btnLogin]; 

如果要創建btnLogin並將其添加到self.view自己，在代碼中，然後爲什麼是這樣的n outlet？

@property (nonatomic,strong) IBOutlet UIButton *btnLogin; 

一個出口的東西，已經存在，並且在你的筆尖是實例。因此，在我看來，你可能有兩個對象，其中一個對象將你的引用擦除掉。而另一個按鈕也一樣。

Answer 2

你沒有設置你的財產，替換：

btnLogin = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 

有：

self.btnLogin = [UIButton buttonWithType:UIButtonTypeRoundedRect]; 

，並定義像你的財產：

@property (nonatomic,strong) UIButton *btnLogin; 

執行相同的buttonUser。

Answer 3

設置你的按鈕的hidden後，您立即說

[menuController setRootController:navController animated:YES];} 

這表明，你正在改變接口。但是如果你正在改變界面，你真的可以告訴你的按鈕是否改變了嗎？我不知道你在這裏做什麼，但也許你的按鈕不再在界面中。也許你在界面上看到的是不同的按鈕組。