从本机表单显示 ViewController

Question

我需要从 Xamarin.forms 显示本机控制器 IOS 我已经尝试过了

 UIWindow window = UIApplication.SharedApplication.KeyWindow;
 UIViewController vc = window.RootViewController;

RGLDocReader.Shared.ShowScanner(vc, HandleRGLDocumentReaderCompletion);

这个 How to create navigation in a Xamarin.iOS app?

关注了这个 https://docs.microsoft.com/en-us/xamarin/ios/app-fundamentals/ios-code-only?tabs=macos

本教程工作正常，但是我需要在指定的方法中使用视图控制器，一旦通过视图控制器，我就会得到 null

Answer 1

实际上，导航到 Forms 中的本机控制器并不是一个好的设计。但如果你确实想实现它，你可以使用 DependencyService 。

在表单中

创建界面

public  interface IOpenNativeView
{
   void OpenNativeView();
}

在 iOS 项目中

using xxx.iOS;
using Foundation;
using UIKit;
using Xamarin.Forms;

[assembly: Dependency(typeof(OpenNativeView))]
namespace xxx.iOS
{
    public class OpenNativeView : IOpenNativeView
    {
        void IOpenNativeView.OpenNativeView()
        {
            var CurrentViewController = topViewControllerWithRootViewController(UIApplication.SharedApplication.Delegate.GetWindow().RootViewController);
            CurrentViewController.NavigationController.PushViewController(YourViewController,true);
        }

        UIViewController topViewControllerWithRootViewController(UIViewController rootViewController)
        {
            if (rootViewController is UITabBarController)
            {
                UITabBarController tabBarController = (UITabBarController)rootViewController;
                return topViewControllerWithRootViewController(tabBarController.SelectedViewController);
            }
            else if (rootViewController is UINavigationController)
            {
                UINavigationController navigationController = (UINavigationController)rootViewController;
                return topViewControllerWithRootViewController(navigationController.VisibleViewController);
            }
            else if (rootViewController.PresentedViewController != null)
            {
                UIViewController presentedViewController = rootViewController.PresentedViewController;
                return topViewControllerWithRootViewController(presentedViewController);
            }
            else
            {
                return rootViewController;
            }
        }
    }
}

现在在 ContentPage 中，您可以在想要打开 ViewController 时调用以下行

DependencyService.Get<IOpenNativeView>().OpenNativeView();