iOS UIImagePickerController 自定义导航条背景、标题和按钮的颜色

    UIImagePickerController *imagePickerController = [[UIImagePickerController alloc] init];
    // 左右按钮颜色
    [[UINavigationBar appearance] setBarTintColor:[UIColor whiteColor]] ;
    
    // 标题颜色
    NSMutableDictionary *attrs = [NSMutableDictionary dictionary];
    attrs[NSForegroundColorAttributeName] = [UIColor whiteColor];
    [[UINavigationBar appearance] setTitleTextAttributes:attrs];
    
    // 导航条背景图
    [[UINavigationBar appearance] setBackgroundImage:[UIImage imageNamed:@"backImage"] forBarMetrics:UIBarMetricsDefault];