Extract WebView2 Program Files warning into reusable include snippet

Co-authored-by: jfversluis <[email protected]>

Author: Copilot

docs/user-interface/controls/blazorwebview.md

@@ -33,17 +33,7 @@ Browser developer tools can be used to inspect .NET MAUI Blazor apps. For more i
 > [!NOTE]
 > While Visual Studio installs all the required tooling to develop .NET MAUI Blazor apps, end users of .NET MAUI Blazor apps on Windows must install the [WebView2](https://developer.microsoft.com/microsoft-edge/webview2/) runtime.
 
-> [!WARNING]
-> On Windows, apps using <xref:Microsoft.AspNetCore.Components.WebView.Maui.BlazorWebView> that are installed to the `Program Files` directory may fail to render content properly. This occurs because WebView2 attempts to write its cache and user data files to the app's installation directory, which has restricted write permissions in `Program Files`. To resolve this issue, set the `WEBVIEW2_USER_DATA_FOLDER` environment variable before the <xref:Microsoft.AspNetCore.Components.WebView.Maui.BlazorWebView> is initialized:
-> 
-> ```csharp
-> #if WINDOWS
-> var userDataFolder = Path.Combine(FileSystem.AppDataDirectory, "WebView2");
-> Environment.SetEnvironmentVariable("WEBVIEW2_USER_DATA_FOLDER", userDataFolder);
-> #endif
-> ```
-> 
-> Place this code in your `App.xaml.cs` constructor or in `Platforms\Windows\App.xaml.cs` before any <xref:Microsoft.AspNetCore.Components.WebView.Maui.BlazorWebView> is created. This directs WebView2 to use a writable location in the user's AppData directory instead of the restricted Program Files location.
+[!INCLUDE [WebView2 Program Files warning](includes/webview2-program-files-warning.md)]
 
 For more information about Blazor Hybrid apps, see [ASP.NET Core Blazor Hybrid](/aspnet/core/blazor/hybrid).
 

docs/user-interface/controls/hybridwebview.md

@@ -34,17 +34,7 @@ The entire app, including the web content, is packaged and runs locally on a dev
 > [!IMPORTANT]
 > By default, the <xref:Microsoft.Maui.Controls.HybridWebView> control won't be available when full trimming or Native AOT is enabled. To change this behavior, see [Trimming feature switches](~/deployment/trimming.md#trimming-feature-switches).
 
-> [!WARNING]
-> On Windows, apps using <xref:Microsoft.Maui.Controls.HybridWebView> that are installed to the `Program Files` directory may fail to render content properly. This occurs because WebView2 attempts to write its cache and user data files to the app's installation directory, which has restricted write permissions in `Program Files`. To resolve this issue, set the `WEBVIEW2_USER_DATA_FOLDER` environment variable before the <xref:Microsoft.Maui.Controls.HybridWebView> is initialized:
-> 
-> ```csharp
-> #if WINDOWS
-> var userDataFolder = Path.Combine(FileSystem.AppDataDirectory, "WebView2");
-> Environment.SetEnvironmentVariable("WEBVIEW2_USER_DATA_FOLDER", userDataFolder);
-> #endif
-> ```
-> 
-> Place this code in your `App.xaml.cs` constructor or in `Platforms\Windows\App.xaml.cs` before any <xref:Microsoft.Maui.Controls.HybridWebView> is created. This directs WebView2 to use a writable location in the user's AppData directory instead of the restricted Program Files location.
+[!INCLUDE [WebView2 Program Files warning](includes/webview2-program-files-warning.md)]
 
 ## Create a .NET MAUI HybridWebView app
 

docs/user-interface/controls/includes/webview2-program-files-warning.md

@@ -0,0 +1,16 @@
+---
+ms.topic: include
+ms.date: 09/19/2025
+---
+
+> [!WARNING]
+> On Windows, apps using WebView2-based controls that are installed to the `Program Files` directory may fail to render content properly. This occurs because WebView2 attempts to write its cache and user data files to the app's installation directory, which has restricted write permissions in `Program Files`. To resolve this issue, set the `WEBVIEW2_USER_DATA_FOLDER` environment variable before any WebView control is initialized:
+> 
+> ```csharp
+> #if WINDOWS
+> var userDataFolder = Path.Combine(FileSystem.AppDataDirectory, "WebView2");
+> Environment.SetEnvironmentVariable("WEBVIEW2_USER_DATA_FOLDER", userDataFolder);
+> #endif
+> ```
+> 
+> Place this code in your `App.xaml.cs` constructor or in `Platforms\Windows\App.xaml.cs` before any WebView control is created. This directs WebView2 to use a writable location in the user's AppData directory instead of the restricted Program Files location.

docs/user-interface/controls/webview.md

@@ -40,17 +40,7 @@ The `Source` property can be set to an `UrlWebViewSource` object or a `HtmlWebVi
 > [!IMPORTANT]
 > A <xref:Microsoft.Maui.Controls.WebView> must specify its <xref:Microsoft.Maui.Controls.VisualElement.HeightRequest> and <xref:Microsoft.Maui.Controls.VisualElement.WidthRequest> properties when contained in a <xref:Microsoft.Maui.Controls.HorizontalStackLayout>, <xref:Microsoft.Maui.Controls.StackLayout>, or <xref:Microsoft.Maui.Controls.VerticalStackLayout>. If you fail to specify these properties, the <xref:Microsoft.Maui.Controls.WebView> will not render.
 
-> [!WARNING]
-> On Windows, apps using <xref:Microsoft.Maui.Controls.WebView> that are installed to the `Program Files` directory may fail to render content properly. This occurs because WebView2 attempts to write its cache and user data files to the app's installation directory, which has restricted write permissions in `Program Files`. To resolve this issue, set the `WEBVIEW2_USER_DATA_FOLDER` environment variable before the <xref:Microsoft.Maui.Controls.WebView> is initialized:
-> 
-> ```csharp
-> #if WINDOWS
-> var userDataFolder = Path.Combine(FileSystem.AppDataDirectory, "WebView2");
-> Environment.SetEnvironmentVariable("WEBVIEW2_USER_DATA_FOLDER", userDataFolder);
-> #endif
-> ```
-> 
-> Place this code in your `App.xaml.cs` constructor or in `Platforms\Windows\App.xaml.cs` before any <xref:Microsoft.Maui.Controls.WebView> is created. This directs WebView2 to use a writable location in the user's AppData directory instead of the restricted Program Files location.
+[!INCLUDE [WebView2 Program Files warning](includes/webview2-program-files-warning.md)]
 
 ## Display a web page