iOS-UINavigationBar 设置背景图片

    /// 统一设置导航栏外观
    - (void)setNavigationBarStyle
    {
        UINavigationBar *navBar = [UINavigationBar appearance];
        /** 设置导航栏背景图片 */
        [navBar setBackgroundImage:[UIImage imageNamed:@"NavBar64"] forBarMetrics:UIBarMetricsDefault];
        /** 设置导航栏标题文字颜色 */
        NSDictionary *dict = @{
                               NSForegroundColorAttributeName : [UIColor whiteColor]
                               };
        [navBar setTitleTextAttributes:dict];
    }