Add share sheet support

src/WinUIEx/Share.cs

@@ -0,0 +1,73 @@
+using System;
+
+using Windows.ApplicationModel.DataTransfer;
+
+namespace WinUIEx
+{
+    // https://learn.microsoft.com/en-us/windows/apps/develop/windows-integration/integrate-sharesheet-send#implement-share-for-desktop-apps-winui-3-wpf-winforms
+
+    [System.Runtime.InteropServices.ComImport]
+    [System.Runtime.InteropServices.Guid("3A3DCD6C-3EAB-43DC-BCDE-45671CE800C8")]
+    [System.Runtime.InteropServices.InterfaceType(
+        System.Runtime.InteropServices.ComInterfaceType.InterfaceIsIUnknown)]
+    interface IDataTransferManagerInterop
+    {
+        IntPtr GetForWindow([System.Runtime.InteropServices.In] IntPtr appWindow,
+            [System.Runtime.InteropServices.In] ref Guid riid);
+        void ShowShareUIForWindow(IntPtr appWindow);
+    }
+
+    public partial class WindowEx
+    {
+        private DataTransferManager? _dtm;
+
+        // Call this from your window or form constructor (or load handler):
+        private void InitializeShare()
+        {
+            // Retrieve the window handle (HWND) for the current window:
+            //   WinUI 3:  IntPtr hWnd = WinRT.Interop.WindowNative.GetWindowHandle(this);
+            //   WPF:      IntPtr hWnd = new System.Windows.Interop.WindowInteropHelper(this).Handle;
+            //   WinForms: IntPtr hWnd = this.Handle;
+            IntPtr hWnd = WinRT.Interop.WindowNative.GetWindowHandle(this);
+
+            IDataTransferManagerInterop interop =
+                DataTransferManager.As<IDataTransferManagerInterop>();
+
+            // IID of DataTransferManager, passed as the riid to GetForWindow:
+            Guid dtmIid = new(0xa5caee9b, 0x8708, 0x49d1, 0x8d, 0x36, 0x67, 0xd2, 0x5a, 0x8d, 0xa0, 0x0c);
+            _dtm = WinRT.MarshalInterface<DataTransferManager>.FromAbi(interop.GetForWindow(hWnd, dtmIid));
+        }
+
+        /// <summary>
+        /// Displays the Windows Share UI for this window and supplies the specified
+        /// <see cref="DataPackage"/> when the user completes the share operation.
+        /// </summary>
+        /// <param name="data">
+        /// The data package to share. This is provided to the Share UI when the
+        /// <c>DataRequested</c> event is raised.
+        /// </param>
+        /// <exception cref="InvalidOperationException">
+        /// Thrown if <see cref="InitializeShare"/> has not been called before invoking this method.
+        /// </exception>
+        public void Share(DataPackage data)
+        {
+            if (_dtm is null) 
+            {
+                throw new InvalidOperationException("Share has not been initialized. Call InitializeShare() first.");
+            }
+
+            void handler(DataTransferManager sender, DataRequestedEventArgs args)
+            {
+                args.Request.Data = data;
+                if (_dtm is not null) {
+                    _dtm.DataRequested -= handler;
+                }
+            }
+
+            _dtm.DataRequested += handler;
+            var hWnd = WinRT.Interop.WindowNative.GetWindowHandle(this);
+            var interop = DataTransferManager.As<IDataTransferManagerInterop>();
+            interop.ShowShareUIForWindow(hWnd);
+        }
+    }
+}

src/WinUIEx/WindowEx.cs

@@ -61,6 +61,8 @@ public WindowEx()
             Grid.SetRow(windowArea, 1);
             rootContent.Children.Add(windowArea);
 
+            InitializeShare();
+
             this.Content = rootContent;
         }
 

src/WinUIExSample/Pages/Dialogs.xaml

@@ -20,6 +20,7 @@
             <Button Content="Show dialog" Click="ShowDialog_Click" />
             <Button Content="Show OK/Cancel" Click="ShowDialog2_Click" />
             <Button Content="Show 3-option dialog" Click="ShowDialog3_Click" />
+            <Button Content="Show share sheet" Click="ShowShareSheet_Click" />
             <TextBlock x:Name="resultText" />
         </StackPanel>
     </Grid>

src/WinUIExSample/Pages/Dialogs.xaml.cs

@@ -60,10 +60,20 @@ private async void ShowDialog3_Click(object sender, RoutedEventArgs e)
                 new Windows.UI.Popups.UICommand("Blue Pill"),
                 new Windows.UI.Popups.UICommand("Cancel")
             };
-            string message = "This is your last chance. After this, there is no turning back. You take the blue pill – the story ends, you wake up in your bed and believe whatever you want to believe. You take the red pill – you stay in Wonderland, and I show you how deep the rabbit hole goes. Remember, all I'm offering is the truth – nothing more.";
+            string message = "This is your last chance. After this, there is no turning back. You take the blue pill � the story ends, you wake up in your bed and believe whatever you want to believe. You take the red pill � you stay in Wonderland, and I show you how deep the rabbit hole goes. Remember, all I'm offering is the truth � nothing more.";
             var result = await MainWindow.ShowMessageDialogAsync(message, commands, cancelCommandIndex: 2, title: "Morpheus Asks");
             resultText.Text = "You chose: " + result.Label;
         }
 
+        private async void ShowShareSheet_Click(object sender, RoutedEventArgs e)
+        {
+            resultText.Text = "";
+            var data = new Windows.ApplicationModel.DataTransfer.DataPackage();
+            data.Properties.Title = "WinUIEx Sample Share";
+            data.SetUri(new Uri("https://github.com/dotMorten/WinUIEx"));
+            data.SetText("Hello from WinUIEx!");
+            MainWindow.Share(data);
+        }
+
     }
 }