Xamarin Android

Using Citrix micro VPN SDKs for Xamarin.Forms

July 31, 2023

Contributed by:

Citrix.Xamarin.Forms.MAMSDK exposes APIs that can be used for micro VPN tunneling for an app developed using Xamarin.Forms. These APIs are provided through a dependency service such as MicroVPNService. This class has a platform-specific implementation to invoke native platform functionality from shared code.

Sample code reference for the XAML Binding class to call MicroVPNService.cs dependency service is as follows:

    public partial class MainPage : ContentPage, IStartTunnelCallback
    {
        public MainPage()
        {
            InitializeComponent();
            urlEntry.Text = "http://mycompanyinternalwebsite.com";
            IMicroVPNService service = DependencyService.Get<IMicroVPNService>();
            service.Init();
        }
        void OnStartTunnel(object sender, EventArgs args)
        {
            activityIndicator.IsRunning = true;
            IMicroVPNService service = DependencyService.Get<IMicroVPNService>();
            service.StartTunnel(this);
        }
        public void OnSuccess()
        {
            activityIndicator.IsRunning = false;
        }
        public void OnError(StartTunnelError error)
        {
            activityIndicator.IsRunning = false;
            DisplayAlert("Error", error.ToString(), "OK");
        }
        void OnStopTunnel(object sender, EventArgs args)
        {
            IMicroVPNService service = DependencyService.Get<IMicroVPNService>();
            service.StopTunnel();
        }
        void OnCheckTunnel(object sender, EventArgs args)
        {
            IMicroVPNService service = DependencyService.Get<IMicroVPNService>();
            bool isRunning = service.IsNetworkTunnelRunning();
            DisplayAlert("Info", isRunning ? "Tunnel is started" : "Tunnel is stopped", "OK");
        }
        async void OnWebView(object sender, EventArgs args)
        {
            activityIndicator.IsRunning = false;
            await Navigation.PushAsync(new WebViewPage(urlEntry.Text));
        }
        async void OnHttpClient(object sender, EventArgs args)
        {
            activityIndicator.IsRunning = true;
            try
            {
                IMicroVPNService service = DependencyService.Get<IMicroVPNService>();
                HttpClient httpClient = service.CreateHttpClient();
                var result = await httpClient.GetStringAsync(urlEntry.Text);
                await DisplayAlert("HttpClient", result, "OK");
            }
            catch (Exception ex)
            {
                await DisplayAlert("Error", ex.Message, "OK");
            }
            finally
            {
                activityIndicator.IsRunning = false;
            }
        }
    }
<!--NeedCopy-->

Initialize the tunnel by calling the DependencyService.Init() method:

 IMicroVPNService service = DependencyService.Get<IMicroVPNService>();
 service.Init();
 <!--NeedCopy-->

Start the micro VPN tunnel asynchronously by calling the DependencyService.StartTunnel() method. The results are returned through an IStartTunnelCallback callback.

 IMicroVPNService service = DependencyService.Get<IMicroVPNService>();
 service.StartTunnel(new MyCallback());
 <!--NeedCopy-->

The callback has two methods OnSuccess() and OnError(). Depending on start tunnel success or failure, it calls the respective methods.

 public class MyCallback : IStartTunnelCallback
 {
     public void OnSuccess()
     {
         // Tunnel is running. You can send network request now.
     }
     public void OnError(StartTunnelError error)
     {
         // Tunnel failed to start. Check error for an appropriate error code.
     }
 }
 <!--NeedCopy-->

Stop the micro VPN tunnel by calling the DependencyService.StopTunnel() method.

 IMicroVPNService service = DependencyService.Get<IMicroVPNService>();
 service.StopTunnel();
 <!--NeedCopy-->

Verify the tunnel status by calling the DependencyService.IsNetworkTunnelRunning() method. If the tunnel is running, the method returns TRUE. Otherwise, it returns FALSE.
```
 IMicroVPNService service = DependencyService.Get<IMicroVPNService>();
 service.IsNetworkTunnelRunning();
 
```
Create an HttpClient by calling the DependencyService.CreateHttpClient() method. It returns an HttpClient object that is enabled for tunneling. Ensure that the app has started the tunnel before calling this method.
```
 IMicroVPNService service = DependencyService.Get<IMicroVPNService>();
 service.CreateHttpClient();
 
```

Enable WebView for tunneling by creating a custom WebView renderer class inside the **.Android** project by inheriting from the **MvpnWebViewRenderer** class. This will enable WebView tunneling for Xamarin.Forms on the Android platform.

 using Android.Content;
 using Android.Webkit;
 using Com.Citrix.Mvpn.Api;
 using MvpnTestFormsApp.Droid;
 using Xamarin.Forms;
 using Xamarin.Forms.Platform.Android;

 [assembly: ExportRenderer(typeof(Xamarin.Forms.WebView), typeof(XamarinWebViewRenderer))]
 namespace MvpnTestFormsApp.Droid
 {
     public class XamarinWebViewRenderer : MvpnWebViewRenderer
     {
         public XamarinWebViewRenderer(Context context) : base(context)
         {
         }
         public override WebViewClient CreateWebViewClient()
         {
             return new FormsWebViewClient(this);
         }
     }
 }
 <!--NeedCopy-->

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Using Citrix micro VPN SDKs for Xamarin.Forms

July 31, 2023

Contributed by:

July 31, 2023

Contributed by:

Using Citrix micro VPN SDKs for Xamarin.Forms

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