Question

如何在我的实现中触发navigationController：willShowViewController委托方法，以便导航控制器中的所有视图控制器都符合colorWithHexString＃faf6f5？

目前，我的FirstViewController将会显示，但它似乎没有调用委托方法来更改它的导航栏的颜色（以及随后堆叠到导航控制器上的所有其他视图控制器）。请注意，我已将“UINavigationControllerDelegate”添加到我的app delegate头文件中。

//In App Delegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    //Set First View
    FirstViewController *firstView = [[FirstViewController alloc]init];

    // pushes a nav con 
    UINavigationController *tempNavcon = [[UINavigationController alloc]initWithRootViewController:firstView];
    self.navcon = tempNavcon;

    [self.window addSubview:navcon.view];

}

- (void)navigationController:(UINavigationController *)navigationController 
  willShowViewController:(UIViewController *)viewController animated:(BOOL)animated{

    navigationController.navigationBar.tintColor = [UIColor colorWithHexString:@"#faf6f5"];

}

Answer 1

您是否有理由尝试在事件方法中更改tintColor而不是在创建UINavigationBar实例时？

Answer 2

这是你如何做到的。（请注意，UIColor不接受十六进制值;您应该使用RGB值，或选中this page。

 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    //Initialize your view controller.
    FirstViewController * firstView = [[FirstViewController alloc] init];

    // Create an instance of a UINavigationController. Its stack contains only firstView.
    UINavigationController *navController = [[UINavigationController alloc]
                                             initWithRootViewController:firstView];

    //Here is where you set the color of the navigationBar. See my note above for using RGB.
    navController.navigationBar.tintColor = [UIColor greenColor];

    // You can now release the firstView here, navController will retain it
    [firstView release];

    // Place navigation controller's view in the window hierarchy
    [[self window] setRootViewController:navController];

    [navController release];

    [self.window makeKeyAndVisible];
    return YES;
}

如何在AppDelegate中触发navigationController：willShowViewController委托方法

2 个答案: