自定义导航条的颜色

#import "AppDelegate.h"
#import "RootViewController.h"

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    
    RootViewController *rootVC=[[RootViewController alloc]init];
    UINavigationController *nav=[[UINavigationController alloc]initWithRootViewController:rootVC];
    
   // UIBarMetricsDefault:用竖着（拿手机）时UINavigationBar的标准的尺寸来显示UINavigationBar.
    //UIBarMetricsLandscapePhone:用横着时UINavigationBar的标准尺寸来显示UINavigationBar
    [nav.navigationBar setBackgroundImage:[UIImage imageNamed:@"1.jpg"] forBarMetrics:UIBarMetricsDefault];
    
    self.window.rootViewController=nav;
    
    
    
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    return YES;
}