将屏幕的导航栏更改为黑色

Question

I am learning objective-c and having some trouble making the top nav bar black. Here's what I have so far:

// AppDelegate.h
#import <UIKit/UIKit.h>

@interface AppDelegate : UIResponder <UIApplicationDelegate>

@property (strong, nonatomic) UIWindow *window;
@property (strong, nonatomic) UINavigationController *navigationController;
@end

// AppDelegate.m
#import "AppDelegate.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.navigationController.navigationBar.barStyle = UIBarStyleBlackOpaque;  // optional
    return YES;
}

What am I doing wrong here / not understanding about this? And how would this be fixed? Is it because I'm not synthesizing the navigationController? (when do you need to synthesize something?)

Answer 1

try by setting the Tint

[navbar setTint color:[uicolor blackColor]];

or

navigationController.navigationBar.barTintColor = [UIColor greenColor];

Answer 2

This should be done in viewWillappear or didappear

By default the UINavigationBar on an iOS app is blue. Apple have some built-in styles that you can use

[self.navigationController.navigationBar setBarStyle:UIBarStyleBlackOpaque];

The options available are:

UIBarStyleBlack
UIBarStyleBlackOpaque
UIBarStyleBlackTranslucent
UIBarStyleDefault

UIBarStyleBlackOpaque and UIBarStyleTranslucent have been depreciated. You should use UIBarStyleBlack and set property 'translucent' to yes if needed .

You can also change the colour to any colour you wish using one of the two lines of codes below and adjusting the colour values.

self.navigationController.navigationBar.tintColor = [UIColor colorWithRed:.7 green:.5 blue:.2 alpha:1];


self.navigationController.navigationBar.tintColor = [UIColor blackColor];

Answer 3

If you are trying to make a application with a navigation controller stack it will usually look something like this.

//Appdelegate.h
#import <UIKit/UIKit.h>
@interface AppDelegate : UIResponder <UIApplicationDelegate>
@property (strong, nonatomic) UIWindow *window;
@end

//Appdelegate.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    MyCustomViewController *vc = [[MyCustomViewController alloc] init];
    UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:vc];
    navigationController.navigationBar.barStyle = UIBarStyleBlack;
    self.window.rootViewController = navigationController;
    [self.window makeKeyAndVisible];

    return YES;
}

Answer 4

使用这可能会有所帮助

self.navigationController.navigationBar.tintColor = [UIColor blackColor];