UIImagePickerController 状态栏颜色改变，自定义返回按钮

UIImagePickerController

在相册中选择图片时，推出图片选择的控制器时，状态会变为默认颜色。点取消返回后却没有变回去。

如果不想改变颜色，可以用下面的方法：

- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    [UIApplication sharedApplication].statusBarStyle = UIStatusBarStyleLightContent;
}

UIImagePickerController是继承至UINavigationController。如果其他地方的UINavigationController用的UINavigationController的子类，并且自定义了返回按钮。在UIImagePickerController中的返回按钮不会改变，可以用下面的方法：

- (void)navigationController:(UINavigationController *)navigationController willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    _imageNavigationController = navigationController;
    if (viewController.navigationItem.leftBarButtonItem == nil && [navigationController.viewControllers count] > 1) {
        viewController.navigationItem.leftBarButtonItem =[self createBackButton:navigationController];
    }
}

-(UIBarButtonItem*)createBackButton:(UINavigationController *)navigationController
{
    UIBarButtonItem *barButtonItem = [[UIBarButtonItem alloc]initWithImage:[UIImage imageNamed:@"back"] style:UIBarButtonItemStyleBordered target:self action:@selector(popViewController)];
    return barButtonItem;
}

-(void)popViewController
{
    [_imageNavigationController popViewControllerAnimated:YES];
}