ios - iPhone 导航栏标题文本颜色在 iOS 11 中的 viewWillAppear() 或 viewWillDisappear 函数中不会改变

Question

错误在 iOS 10 中没有发生。 标题文本颜色的默认值是黑色，当导航到新屏幕 (2) 时，我在 viewWillAppear() 中将标题文本颜色更改为粉红色，在 viewWillDisappear 中我将其更改为默认颜色。 逻辑在 iOS 10 上没问题，但在 iOS 11 上，第一个带有栏标题颜色的屏幕是粉红色(预期是默认颜色)

此外:当在 viewWillAppear() 中添加逻辑改变颜色时(在这种情况下颜色不会改变)但是 这在 viewDidAppear() 中有效，但是有错误，标题是闪烁变化从屏幕 2 返回屏幕 1 时的颜色

屏幕 2 中的源代码(适用于 iOS 10):

#define NAVBAR_TITLE_FONT_ATTR @{ UITextAttributeFont : [UIFont boldSystemFontOfSize:19], UITextAttributeTextColor: [UIColor colorWithRed:9/255.0 green:34/255.0 blue:83/255.0 alpha:1]}
#define NAVBAR_TINT_COLOR [UIColor colorWithRed:97/255.0 green:113/255.0 blue:146/255.0 alpha:1]
#define NAVBAR_BG_COLOR [UIColor colorWithRed:247/255.0 green:247/255.0 blue:247/255.0 alpha:1]
#define LIGHT_BLUE_COLOR [UIColor colorWithRed:0.04 green:0.13 blue:0.33 alpha:1.0]


-(void)viewWillAppear:(BOOL)animated {

    [super viewWillAppear:animated];
    [self.navigationController.navigationBar setBackgroundImage:[UIImage new]                                              forBarMetrics:UIBarMetricsDefault];
    self.navigationController.navigationBar.shadowImage = [UIImage new];
    self.navigationController.navigationBar.translucent = YES;
    self.navigationController.view.backgroundColor = [UIColor clearColor];
    textColor = [UIColor pinkColor] 
    self.navigationController.navigationBar.tintColor = textColor;
    self.navigationController.navigationBar.titleTextAttributes =  [NSDictionary dictionaryWithObjectsAndKeys:
                                                                    textColor, NSForegroundColorAttributeName,
                                                                    [UIFont boldSystemFontOfSize:19], NSFontAttributeName,nil];

}

-(void)viewWillDisappear:(BOOL)animated {

    [super viewWillDisappear:animated];

    self.navigationController.navigationBar.tintColor = NAVBAR_TINT_COLOR;
    self.navigationController.navigationBar.barTintColor = NAVBAR_BG_COLOR;
    self.navigationController.navigationBar.translucent = NO;
    [self.navigationController.navigationBar setTitleTextAttributes:NAVBAR_TITLE_FONT_ATTR];
    [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleDefault];
}

正确答案是:

- (void)willMoveToParentViewController:(UIViewController *)parent {

    if (!parent) {
        self.navigationController.navigationBar.titleTextAttributes =  @{
                                                                         NSForegroundColorAttributeName: [UIColor blackColor]
                                                                         };

 }

}

谢谢@Phu Nguyen

Detecting when the 'back' button is pressed on a navbar

Answer 1

你在第二个 View Controller 中试过这个吗？

- (void)willMoveToParentViewController:(UIViewController *)parent {
  [super willMoveToParentViewController:parent];
    NSLog(@"Parent view controller: %@", parent);
    if (!parent) {
        self.navigationController.navigationBar.titleTextAttributes =  @{
                                                                         NSForegroundColorAttributeName: [UIColor blackColor]
                                                                         };
    }
}