iOS WKWebView 调用原生相册页面展示问题

H5 页面直接调起手机的相册和浏览功能，不通过App 开发人员，不使用JS交互。H5开发人员使用了这样一段代码，就可以直接调起相机、相册和浏览功能，相机受权限影响，而相册不受App权限的影响：

<input type=\"file\" accept=\"image/*;capture=camera\">

那么打开的页面是通过H5 打开的，页面样式与App的页面样式不统一，但是App开发者，找不到对应的控制器，也无法修改样式。

那么我们需要做的是找到对应的控制器
使用Swizzling
具体原理是给UIViewControlle创建分类UIViewController+Swizzling ，hook到-viewWillAppear: 方法，在交换的自己重写的方法中改变导航栏的样式，代码如下：

- (void)swizzlingViewWillAppear:(BOOL)animated {
    [self swizzlingViewWillAppear:animated];

    if ([self isMemberOfClass:NSClassFromString(@"PUPhotoPickerHostViewController")] || [self isMemberOfClass:NSClassFromString(@"UIDocumentPickerViewController")]) {
        [self configureRongCloudNavigation];
    }
}

+ (void)load {
    [super load];
    //原本的willAppear方法
    Method willAppearOriginal = class_getInstanceMethod([self class], @selector(viewWillAppear:));
    //用于交换的willAppear方法
    Method willAppearNew = class_getInstanceMethod([self class], @selector(swizzlingViewWillAppear:));
    //交换
    if (!class_addMethod([self class], @selector(viewWillAppear:), method_getImplementation(willAppearNew), method_getTypeEncoding(willAppearNew))) {
        method_exchangeImplementations(willAppearOriginal, willAppearNew);
    }
}

- (void)configureRongCloudNavigation {
    //点击系统相册弹出的控制器
    if ([self isMemberOfClass:NSClassFromString(@"PUPhotoPickerHostViewController")]) {
        UIBarButtonItem *barItem = [UIBarButtonItem appearance];
        barItem.tintColor = [UIColor whiteColor];
        UINavigationBar *navBar = [UINavigationBar appearance];
        [navBar setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor whiteColor]}];
        navBar.tintColor = [UIColor whiteColor];
    }
    
    //点击浏览弹出的控制器
    if ([self isMemberOfClass:NSClassFromString(@"UIDocumentPickerViewController")]) {
        UIBarButtonItem *barItem = [UIBarButtonItem appearance];
        barItem.tintColor = [UIColor blueColor];
        UINavigationBar *navBar = [UINavigationBar appearance];
        [navBar setTitleTextAttributes:@{NSForegroundColorAttributeName:[UIColor blueColor]}];
        navBar.tintColor = [UIColor blueColor];
    }
}

到此页面样式就修改完成了。