Create a WinUI 3 app

In Visual Studio, select File -> New -> Project.

In the project drop-down filters, select C#, Windows, and WinUI, respectively.

Select one of the following project types and click Next.

• Blank App, Packaged (WinUI 3 in Desktop): Creates a desktop C# .NET app with a WinUI-based user interface. The generated project is configured with the package manifest and other support needed to build the app into an MSIX package without the use of a separate packaging project. For more information about this project type, see Package your app using single-project MSIX.

  Note

  If you installed the Windows App SDK 1.0 Preview 2 with Visual Studio 2019, this project template has a known issue that results in a build error. To resolve this issue, install the Single-project MSIX Packaging Tools for Visual Studio 2019 VSIX extension after you install the Windows App SDK 1.0 Preview 2.

• Blank App, Packaged with Windows Application Packaging Project (WinUI 3 in Desktop): Creates a desktop C# .NET app with a WinUI-based user interface. The generated solution includes a separate Windows Application Packaging Project that is configured to build the app into an MSIX package.

Enter a project name, choose any other options as desired, and click Create.

In the following dialog box, set the Target version to Windows 10, version 2004 (build 19041) and Minimum version to Windows 10, version 1809 (build 17763) and then click OK.

At this point, Visual Studio generates one or more projects:

• Project name (Desktop): This project contains your app's code. The App.xaml file and App.xaml.cs code-behind file define an Application class that represents your app instance. The MainWindow.xaml file and MainWindow.xaml.cs code-behind file define a MainWindow class that represents the main window displayed by your app. These classes derive from types in the Microsoft.UI.Xaml namespace provided by WinUI.

  If you used the Blank App, Packaged (WinUI 3 in Desktop) project template, this project also includes the package manifest for building the app into an MSIX package.

  

• Project name (Package): This project is generated only if you use the Blank App, Packaged with Windows Application Packaging Project (WinUI 3 in Desktop) project template. This project is a Windows Application Packaging Project that is configured to build the app into an MSIX package. This project contains the package manifest for your app, and it is the startup project for your solution by default.

  

To add a new item to your app project, right-click the Project name (Desktop) project node in Solution Explorer and select Add -> New Item. In the Add New Item dialog box, select the WinUI tab, choose the item you want to add, and then click Add. For more details about the available items, see Item templates for WinUI 3.

Build and run your solution on your development computer to confirm that the app runs without errors.

Install the Windows App SDK runtime and MSIX packages. These are required to run and deploy your unpackaged app.

Create a new app using the "Blank App, Packaged (WinUI 3 in Desktop)" project template. Starting with a packaged app is required to use XAML diagnostics.

Add this property to the project file:

<WindowsPackageType>None</WindowsPackageType>

To debug in Visual Studio, select the 'Unpackaged' launch profile in the Start drop down. Otherwise, you'll see an error: "The project doesn't know how to run the profile …"

If you haven't already done so, install the Windows App SDK runtime and MSIX packages, which are required to run and deploy your app.

Build and run. See the Windows App SDK tutorial for deploying unpackaged C# apps.

for additional deployment information. This tutorial will guide you through using the bootstrapper API to initialize the Bootstrapper component so your app can use Windows App SDK and WinUI 3 APIs.

In Visual Studio, select File -> New -> Project.

In the project drop-down filters, select C++, Windows, and WinUI.

Select one of the following project types and click Next.

• Blank App, Packaged (WinUI 3 in Desktop): Creates a desktop C++ app with a WinUI-based user interface. The generated project is configured with the package manifest and other support needed to build the app into an MSIX package without the use of a separate packaging project. For more information about this project type, see Package your app using single-project MSIX.

  Note

  This project type only supports a single executable in the generated MSIX package. If you need to combine multiple executables into a single MSIX package, you must use the Blank App, Packaged with Windows Application Packaging Project (WinUI 3 in Desktop) project template or add a Windows Application Packaging Project to your solution.

• Blank App, Packaged with Windows Application Packaging Project (WinUI 3 in Desktop): Creates a desktop C++ app with a WinUI-based user interface. The generated solution includes a separate Windows Application Packaging Project that is configured to build the app into an MSIX package.

Enter a project name, choose any other options as desired, and click Create.

In the following dialog box, set the Target version to Windows 10, version 2004 (build 19041) and Minimum version to Windows 10, version 1809 (build 17763) and then click OK.

At this point, Visual Studio generates one or more projects:

• Project name (Desktop): This project contains your app's code. The App.xaml and various App code files define an Application class that represents your app instance, and the MainWindow.xaml and various MainWindow code files define a MainWindow class that represents the main window displayed by your app. These classes derive from types in the Microsoft.UI.Xaml namespace provided by WinUI.

  If you used the Blank App, Packaged (WinUI 3 in Desktop) project template, this project also includes the package manifest for building the app into an MSIX package.

  

• Project name (Package): This project is generated only if you use the Blank App, Packaged with Windows Application Packaging Project (WinUI 3 in Desktop) project template. This project is a Windows Application Packaging Project that is configured to build the app into an MSIX package. This project contains the package manifest for your app, and it is the startup project for your solution by default.

  

To add a new item to your app project, right-click the Project name (Desktop) project node in Solution Explorer and select Add -> New Item. In the Add New Item dialog box, select the WinUI tab, choose the item you want to add, and then click Add. For more details about the available items, see Item templates for WinUI 3.

Build and run your solution on your development computer to confirm that the app runs without errors.

Install the Single-project MSIX Packaging Tools.

Install the Windows App SDK runtime and MSIX packages. These are required to run and deploy your unpackaged app.

Install the Microsoft Visual C++ Redistributable (VCRedist) for the appropriate architecture

• The latest version of the redistributable is compatible with the latest Visual Studio GA release, as well as all versions of Visual Studio used to build Windows App SDK binaries.
• Insider builds of Visual Studio may have installed a later version of VCRedist, and running the public version will then fail with this error, which can be ignored: Error 0x80070666: Cannot install a product when a newer version is installed.

Create a new app using the "Blank App, Packaged (WinUI 3 in Desktop)" project template. Starting with a packaged app is required to use XAML diagnostics.

Add this property to the project file:

<WindowsPackageType>None</WindowsPackageType>

Change 'AppxPackage' property to false:

 <AppxPackage>false</AppxPackage>

If you haven't already done so, install the Windows App SDK runtime and MSIX packages, which are required to run and deploy your app.

Build and run. See the Windows App SDK tutorial for deploying unpackaged C++ apps for additional deployment information. This tutorial will guide you through using the bootstrapper API to initialize the Bootstrapper component so your app can use Windows App SDK and WinUI 3 APIs. -->