导航状态栏定制

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    [[UIApplication sharedApplication] setStatusBarStyle:UIStatusBarStyleLightContent];
    [[UIApplication sharedApplication] setStatusBarHidden:NO];
    NSDictionary *attributes = @{ NSFontAttributeName: [UIFont fontWithName:@"GillSans-Light" size:20],
                                  NSForegroundColorAttributeName: [UIColor whiteColor]};
    [[UINavigationBar appearance] setTitleTextAttributes:attributes];
    [[UINavigationBar appearance] setTintColor:[UIColor whiteColor]];

    return YES;
}