Add new OpenFolderDialog API article

dotnet-desktop-guide/net/wpf/windows/dialog-boxes-overview.md

@@ -43,7 +43,7 @@ Windows implements different kinds of reusable dialog boxes that are common to a
 
 Since these dialog boxes are provided by the operating system, they're shared among all the applications that run on the operating system. These dialog boxes provide a consistent user experience, and are known as _common dialog boxes_. As a user uses a common dialog box in one application, they don't need to learn how to use that dialog box in other applications.
 
-WPF encapsulates the open file, save file, and print common dialog boxes and exposes them as managed classes for you to use in standalone applications.
+WPF encapsulates the open file, save file, open folder, and print common dialog boxes and exposes them as managed classes for you to use.
 
 :::image type="content" source="media/dialog-boxes-overview/open-file-dialog-box.png" alt-text="Open file dialog box called from WPF.":::
 
@@ -52,6 +52,7 @@ To learn more about common dialog boxes, see the following articles:
 - [How to display a common dialog box](how-to-open-common-system-dialog-box.md)
 - [Show the Open File dialog box](how-to-open-common-system-dialog-box.md#open-file-dialog-box)
 - [Show the Save File dialog box](how-to-open-common-system-dialog-box.md#save-file-dialog-box)
+- [Open Folder dialog box](how-to-open-common-system-dialog-box.md#open-folder-dialog-box)
 - [Show the Print dialog box](how-to-open-common-system-dialog-box.md#print-dialog-box)
 
 ## Custom dialog boxes

dotnet-desktop-guide/net/wpf/windows/how-to-open-common-system-dialog-box.md

@@ -25,7 +25,7 @@ The open file dialog box is used by file opening functionality to retrieve the n
 
 :::image type="content" source="media/how-to-open-common-system-dialog-box/open-file-dialog-box.png" alt-text="An Open dialog box showing the location to retrieve the file shown from a WPF application.":::
 
-The common open file dialog box is implemented as the <xref:Microsoft.Win32.OpenFileDialog> class and is located in the <xref:Microsoft.Win32> namespace. The following code shows how to create, configure, and show one, and how to process the result.
+The common open file dialog box is implemented as the <xref:Microsoft.Win32.OpenFileDialog> class and is located in the <xref:Microsoft.Win32> namespace. The following code shows how to create, configure, and show the dialog.
 
 :::code language="csharp" source="snippets/how-to-open-common-system-dialog-box/csharp/Window1.xaml.cs" id="OpenFile":::
 :::code language="vb" source="snippets/how-to-open-common-system-dialog-box/vb/Window1.xaml.vb" id="OpenFile":::
@@ -38,18 +38,34 @@ The save file dialog box is used by file saving functionality to retrieve the na
 
 :::image type="content" source="media/how-to-open-common-system-dialog-box/save-file-dialog-box.png" alt-text="A Save As dialog box showing the location to save the file shown from a WPF application.":::
 
-The common save file dialog box is implemented as the <xref:Microsoft.Win32.SaveFileDialog> class, and is located in the <xref:Microsoft.Win32> namespace. The following code shows how to create, configure, and show one, and how to process the result.
+The common save file dialog box is implemented as the <xref:Microsoft.Win32.SaveFileDialog> class, and is located in the <xref:Microsoft.Win32> namespace. The following code shows how to create, configure, and show the dialog.
 
 :::code language="csharp" source="snippets/how-to-open-common-system-dialog-box/csharp/Window1.xaml.cs" id="SaveFile":::
 :::code language="vb" source="snippets/how-to-open-common-system-dialog-box/vb/Window1.xaml.vb" id="SaveFile":::
 
 For more information on the save file dialog box, see <xref:Microsoft.Win32.SaveFileDialog?displayProperty=nameWithType>.
 
+## Open Folder dialog box
+
+> [!IMPORTANT]
+> The Open Folder dialog box is available in .NET 8.0 and later.
+
+The Open Folder dialog box is used by the user to select one or more folders, and return them to the program. For example, if your program displayed information about a folder, such as the amount of files and the file names in the folder, you can use the Open Folder dialog to let the user choose the folder.
+
+:::image type="content" source="media/how-to-open-common-system-dialog-box/open-folder-dialog-box.png" alt-text="An Open Folder dialog box showing the Pictures folder with the Camera Roll folder selected, shown from a WPF application.":::
+
+The common open folder dialog box is implemented as the <xref:Microsoft.Win32.OpenFolderDialog> class, and is located in the <xref:Microsoft.Win32> namespace. The following code shows how to create, configure, and show the dialog.
+
+:::code language="csharp" source="snippets/how-to-open-common-system-dialog-box/csharp/Window1.xaml.cs" id="OpenFolder":::
+:::code language="vb" source="snippets/how-to-open-common-system-dialog-box/vb/Window1.xaml.vb" id="OpenFolder":::
+
+For more information on the open folder dialog box, see <xref:Microsoft.Win32.OpenFolderDialog?displayProperty=nameWithType>.
+
 ## Print dialog box
 
 The print dialog box is used by printing functionality to choose and configure the printer that a user wants to print data to.
 
-:::image type="content" source="media/how-to-open-common-system-dialog-box/print-data-dialog-box.png" alt-text="A print dialog box shown from a WPF application.":::
+:::image type="content" source="media/how-to-open-common-system-dialog-box/print-data-dialog-box-win11.png" alt-text="A print dialog box shown from a WPF application.":::
 
 The common print dialog box is implemented as the <xref:System.Windows.Controls.PrintDialog> class, and is located in the <xref:System.Windows.Controls> namespace. The following code shows how to create, configure, and show one.
 

dotnet-desktop-guide/net/wpf/windows/snippets/how-to-open-common-system-dialog-box/csharp/Dialogs.csproj

@@ -2,10 +2,9 @@
 
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
-    <TargetFramework>net7.0-windows</TargetFramework>
+    <TargetFramework>net8.0-windows</TargetFramework>
     <UseWPF>true</UseWPF>
     <ApplicationManifest>app.manifest</ApplicationManifest>
-
   </PropertyGroup>
 
 </Project>

dotnet-desktop-guide/net/wpf/windows/snippets/how-to-open-common-system-dialog-box/csharp/Window1.xaml

@@ -10,6 +10,7 @@
         <Button Click="Button_Click">Message Box</Button>
         <Button Click="Save_Click">Save file</Button>
         <Button Click="Open_Click">Open file</Button>
+        <Button Click="OpenFolder_Click">Open folder</Button>
         <Button Click="Print_Click">Print</Button>
     </StackPanel>
 

dotnet-desktop-guide/net/wpf/windows/snippets/how-to-open-common-system-dialog-box/csharp/Window1.xaml.cs

@@ -79,6 +79,54 @@ private void Open_Click(object sender, RoutedEventArgs e)
             //</OpenFile>
         }
 
+        private void OpenFolder_Click(object sender, RoutedEventArgs e)
+        {
+            //<OpenFolder>
+            // Configure open folder dialog box
+            Microsoft.Win32.OpenFolderDialog dialog = new();
+
+            dialog.Multiselect = false;
+            dialog.Title = "Select a folder";
+
+            // Show open folder dialog box
+            bool? result = dialog.ShowDialog();
+
+            // Process open folder dialog box results
+            if (result == true)
+            {
+                // Get the selected folder
+                string fullPathToFolder = dialog.FolderName;
+                string folderNameOnly = dialog.SafeFolderName;
+            }
+            //</OpenFolder>
+        }
+
+        private void OpenFolderMultiple_Click(object sender, RoutedEventArgs e)
+        {
+            //<OpenFolderMultiselect>
+            // Configure open folder dialog box
+            Microsoft.Win32.OpenFolderDialog dialog = new();
+
+            dialog.Multiselect = true;
+            dialog.Title = "Select one or more folders";
+
+            // Show open folder dialog box
+            bool? result = dialog.ShowDialog();
+
+            // Process open folder dialog box results
+            if (result == true)
+            {
+                // Get multiple folder names
+                for (int index = 0; index < dialog.FolderNames.Length; index++)
+                {
+                    // Get the selected folder
+                    string fullPathToFolder = dialog.FolderNames[index];
+                    string folderNameOnly = dialog.SafeFolderNames[index];
+                }
+            }
+            //</OpenFolderMultiselect>
+        }
+
         private void Print_Click(object sender, RoutedEventArgs e)
         {
             //<Print>

dotnet-desktop-guide/net/wpf/windows/snippets/how-to-open-common-system-dialog-box/vb/DialogsVB.vbproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>WinExe</OutputType>
-    <TargetFramework>net7.0-windows</TargetFramework>
+    <TargetFramework>net8.0-windows</TargetFramework>
     <RootNamespace>WindowsOverview</RootNamespace>
     <UseWPF>true</UseWPF>
   </PropertyGroup>

dotnet-desktop-guide/net/wpf/windows/snippets/how-to-open-common-system-dialog-box/vb/Window1.xaml

@@ -10,6 +10,7 @@
         <Button Click="Button_Click">Message Box</Button>
         <Button Click="Save_Click">Save file</Button>
         <Button Click="Open_Click">Open file</Button>
+        <Button Click="OpenFolder_Click">Open folder</Button>
         <Button Click="Print_Click">Print</Button>
     </StackPanel>
 </Window>

dotnet-desktop-guide/net/wpf/windows/snippets/how-to-open-common-system-dialog-box/vb/Window1.xaml.vb

@@ -60,6 +60,51 @@
         '</OpenFile>
     End Sub
 
+    Private Sub OpenFolder_Click(sender As Object, e As RoutedEventArgs)
+        '<OpenFolder>
+        ' Configure open folder dialog box
+        Dim dialog As New Microsoft.Win32.OpenFolderDialog()
+
+        dialog.Multiselect = False
+        dialog.Title = "Select a folder"
+
+        ' Show open folder dialog box
+        Dim result As Boolean? = dialog.ShowDialog()
+
+        ' Process open folder dialog box results
+        If result = True Then
+            ' Get the selected folder
+            Dim fullPathToFolder As String = dialog.FolderName
+            Dim folderNameOnly As String = dialog.SafeFolderName
+        End If
+        '</OpenFolder>
+    End Sub
+
+    Private Sub OpenFolderMultiple_Click(sender As Object, e As RoutedEventArgs)
+        '<OpenFolder>
+        ' Configure open folder dialog box
+        Dim dialog As New Microsoft.Win32.OpenFolderDialog()
+
+        dialog.Multiselect = True
+        dialog.Title = "Select a folder"
+
+        ' Show open folder dialog box
+        Dim result As Boolean? = dialog.ShowDialog()
+
+        ' Process open folder dialog box results
+        If result = True Then
+
+            ' Get multiple folder names
+            For index = 0 To dialog.FolderNames.Length
+                ' Get the selected folder
+                Dim fullPathToFolder As String = dialog.FolderNames(index)
+                Dim folderNameOnly As String = dialog.SafeFolderNames(index)
+            Next
+
+        End If
+        '</OpenFolder>
+    End Sub
+
     Private Sub Print_Click(sender As Object, e As RoutedEventArgs)
         '<Print>
         ' Configure printer dialog box