rightBarButtonItem似乎堆疊時，從一個viewController移動到另一個

我的問題是，我創建了一個rightBarButtonItem爲我的故事板中的每個視圖，rightBarButtonItem在我的應用程序應該跟蹤用戶的項目總成本添加到他們的購物清單。在我的viewDidLoad的第一個ViewController上，我將rightBarButtonItem's customView設置爲UILabel。當移動到另一個ViewController時，我將該ViewController的rightBarButtonItem設置爲前一個ViewController中的一個。但是，當我回到之前的ViewController那ViewController'srightBarButtonItem不會更改時，我嘗試更新它。相反，它看起來像當我移動前一次時所做的，如果我再次移動到相同的ViewController，第一個ViewController的rightBarButtonItem似乎總是落後於它應該返回的位置。換句話說，當移動到另一個ViewController時，ViewController的rightBarButtonItem似乎堆疊起來。rightBarButtonItem似乎堆疊時，從一個viewController移動到另一個

任何幫助，非常感謝。

- 相關代碼：

viewDidLoad中 - 第一的ViewController

double total; 

- (void)viewDidLoad{ 
    total = 0; 
    NSString *text = [NSString stringWithFormat:@"$%.2f", total]; 
    UIFont *cellFont = [UIFont fontWithName:@"Helvetica" size:17.0]; 
    CGSize constraintSize = CGSizeMake(MAXFLOAT, MAXFLOAT); 
    CGSize labelSize = [text sizeWithFont:cellFont constrainedToSize:constraintSize lineBreakMode:NSLineBreakByWordWrapping]; 
    UILabel *customItem = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, labelSize.width, labelSize.height)]; 
    [customItem setText:text]; 
    [customItem setFont:[UIFont fontWithName:@"Helvetica" size:15.0]]; 
    [self.navigationItem.rightBarButtonItem setCustomView:customItem]; 
}

prepareForSegue - 第一的ViewController

- (void)prepareForSegue:(UIStoryboardSegue *)segue sender:(id)sender{ 
    OrderViewController *orderViewController = (OrderViewController *)segue.destinationViewController; 
    [orderViewController.navigationItem.rightBarButtonItem setCustomView:_rightBarButtonItem.customView]; 
}

viewWillDisappear - 第二的ViewController

- (void)viewWillDisappear:(BOOL)animated{ 
    [super viewWillDisappear:animated]; 
// sendTotalBackFromOrder is delegate method upon returning to first ViewController 
    [_delegate sendTotalBackFromOrder:_total]; 
    [self removeFromParentViewController]; 
}

sendTotalBackFromOrder - FirstViewController

// This is the method where it becomes apparent that rightBarButtonItem is being stacked and is always 'behind' where it should be 
- (void)sendTotalBackFromOrder:(double)currTotal{ 
    total = currTotal; 
    NSString *text = [NSString stringWithFormat:@"$%.2f", total]; 
    UIFont *cellFont = [UIFont fontWithName:@"Helvetica" size:17.0]; 
    CGSize constraintSize = CGSizeMake(MAXFLOAT, MAXFLOAT); 
    CGSize labelSize = [text sizeWithFont:cellFont constrainedToSize:constraintSize lineBreakMode:NSLineBreakByWordWrapping]; 
    UILabel *customItem = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, labelSize.width, labelSize.height)]; 
    [customItem setText:text]; 
    [customItem setFont:[UIFont fontWithName:@"Helvetica" size:15.0]]; 
    [self.navigationItem.rightBarButtonItem setCustomView:customItem]; 
}

來源

2015-06-29 thailey01

是sendTotalBackFromOrder：被稱爲？代表在哪裏設置？ – agy

可以在viewWillAppear而不是viewDidLoad –

@agy sendTotalBackFromOrder在我的第二個ViewController'消失'時被調用。 Delegate在第一個ViewController的prepareForSegue方法中設置，我忘記將它添加到描述中。 – thailey01

只要改變在viewDidLoad中和sendTotalBackFromOrder行：

[self.navigationItem.rightBarButtonItem setCustomView:customItem];

爲

UIBarButtonItem *barBtn = [[UIBarButtonItem alloc] initWithCustomView:customItem]; 

self.navigationItem.rightBarButtonItem = barBtn;

來源

2015-06-30 07:17:35 agy

由於@agy像一個魅力一樣工作。我應該想到這一點。 – thailey01

rightBarButtonItem似乎堆疊時，從一個viewController移動到另一個

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