Did you know that you can call Windows 10 WinRT APIs from your WPF and WinForms apps? In this blog post I’ll show you how to display toast messages from a WPF application by using the Windows 10 ToastNotificationManager.

In the previous blog post you learned that you can host UWP Controls in WPF, WinForms, and Win32 with a technology called XAML Islands.

But sometimes you don’t want to include a UWP Control in your WPF app. Instead, you want to call a Windows 10 API. Or maybe you want to do both: Include a UWP control and call a Windows 10 API. In any case, you need to reference the Windows 10 WinRT APIs in your WPF project. Let’s see how to do this.

Reference the Windows 10 WinRT APIs in your WPF project

If you’ve tried already in the past to use Windows 10 WinRT APIs in WPF, you might have come across documentation that said that you have to reference several files …

• … from .NET Framework – like System.Runtime.WindowsRuntime.dll
• and from the corresponding Windows SDK, like Windows.Foundation.UniversalApiContract.winmd

This is not necessary anymore. Microsoft made this whole process much simpler.

All you need to do to use Windows 10 WinRT APIs in your WPF project is to install the NuGet package Microsoft.Windows.SDK.Contracts.

That package is the the so-called Windows 10 WinRT API Pack . Let me quote the package description:

The Windows 10 WinRT API Pack enables you to add the latest Windows Runtime APIs support to your .NET Framework 4.5+ and .NET Core 3.0+ libraries and apps. This package includes all the supported Windows Runtime APIs up to Windows 10 version 1903

Wow, amazing. Just adding a single NuGet package and it works. Let’s try it.

Add the NuGet package

Let’s create a brand new WPF application and let’s install the NuGet package Microsoft.Windows.SDK.Contracts. It’s still in preview, so ensure to check the “Include prerelease” option like below:

When you look at the dependencies of the Microsoft.Windows.SDK.Contracts package, you can see that it brings in the other stuff that you had to add manually before this package existed, like the _System.Runtime.WindowsRuntime.dll _that I mentioned above:

Switch from packages.config to PackageReference

When you install the Microsoft.Windows.SDK.Contracts NuGet package in a .NET Core WPF app, you’re fine. But in a .NET Framework WPF app, you have to switch the NuGet package management format from packages.config to PackageReference, else it won’t work. The description of the Microsoft.Windows.SDK.Contracts package contains also this statement:

Requires default package management format set to PackageReference, and NuGet 4.0 or higher.

If you have a .NET Framework WPF app that still uses packages.config, just right-click on “References” in the Solution Explorer. In the context menu you find a menu item to_“Migrate packages.config to PackageReference”_, as you can see in the screenshot below.

After you clicked that menu item, the packages.config file will be deleted and the references to the NuGet packages are stored in the .csproj file. Great, now installing the NuGet package Microsoft.Windows.SDK.Contracts works fine, and you should see that package including its dependencies in the references like below:

Now, no matter if you’re using .NET Core 3 or .NET Framework, you’re ready to display a toast message from your WPF app. Let’s write the code.

#.net #uwp #windows #wpf #xaml #csharp