Windows 10: A deep-dive into WinUI 3 in desktop apps for Windows 10

Brink · Jul 7, 2020

XAML Islands was our first solution to enable developers to use UWP XAML inside their desktop (Win32) apps. Within a couple of months after the release of XAML Islands, behavioral insights and customer interviews raised some signals about how developers were using it. We discovered that a significant number of apps were using XAML for the entire UI; in fact, many apps were using WPFâs Window and Windows Formsâs Form classes for the sole purpose of hosting XAML. Additionally, interviews revealed that C++ Windows developers were interested in XAML as a replacement for MFC.

This made us think about whether we can help customers further. We listed a set of hypotheses about what Windows developers were expecting and created a prototype to validate/invalidate these hypotheses. The outcome of this validation process was very enlightening. Windows developers were hungry for creating beautiful, modern, and refreshing apps reusing the desktop code (in the form of .NET or C++ Win32) that they had already been using. In most cases, this code needed to run outside of the security sandbox (AppContainer) and work in all versions of Windows 10 in the market. So we extended WinUI 3 to support desktop apps in addition to UWP apps. WinUI 3.0 Preview 1 introduced project templates to create desktop C# .NET 5 apps and C++ 17 desktop apps where the entire user interface is implemented using windows, controls, and other UI elements provided by the WinUI framework.

But enough of so much chatter and letâs get to work! In this blog post Iâm going to focus on building a desktop app with WinUI 3 Preview 1 and .NET, leaving C++ for future posts.

The first step is to install WinUI3 Preview 1 (or Preview 2 when available) in your development machine. I recommend visiting this link and following the Prerequisites instructions to download and install the VSIX that contains the project templates. After that, follow the instructions to create a WinUI 3 desktop app for C# and .NET 5. Press F5 and you will see something like this:

There are a lot of things that you can learn from this project without writing a line of code. The first noticeable thing is that there are two projects in the solution. One is for the Desktop WinUI 3 app itself, and the other is for packaging the app into a MSIX. In Preview 1 itâs required to package your project to run your app. Although MSIX is our recommended packaging technology, weâre aiming to make a UI Framework thatâs independent of the deployment mechanism. This is a temporary limitation that we will address in subsequent previews , as you can see in the Preview 1 known issues documentation.

Embracing .NET 5

If you double click on the WinUI 3 app project, Visual Studio opens the project file with the XML text editor, and you can observe several things. First, C# Desktop WinUI 3 projects embrace the SDK-style project so itâs human readable/understandable. Second, the Target Framework is .NET 5. Desktop WinUI 3 can be used with the next big release in the .NET family. Third, you can see that this project has a reference to the Microsoft.WinUI NuGet package, which pulls in the WinUI 3 tools and runtime.

Code:

<Project Sdk="Microsoft.NET.Sdk">
<PropertyGroup>
<OutputType>WinExe</OutputType>
<TargetFramework>netcoreapp5.0</TargetFramework> <TargetPlatformVersion>10.0.18362.0</TargetPlatformVersion> <TargetPlatformMinVersion>10.0.17134.0</TargetPlatformMinVersion>

<Platforms>x86;x64</Platforms>
<SelfContained>true</SelfContained>
<RuntimeIdentifiers>win-x86;win-x64</RuntimeIdentifiers>
<RuntimeIdentifier>win-$(Platform)</RuntimeIdentifier>
</PropertyGroup>

<ItemGroup>
<PackageReference Include="Microsoft.VCRTForwarders.140" Version="1.0.6" />
<PackageReference Include="Microsoft.WinUI" Version="3.0.0-preview1.200515.3" />
</ItemGroup>

</Project>
Click to expand...

Speaking of tools, WinUI 3 uses the new C#/WinRT projections. The WinUI 3 framework is a set of WinRT components, and while WinRT has similar types and objects as those found in .NET, they are not inherently compatible. The C#/WinRT projections handle the interop between .NET and WinRT, allowing you to freely create and use WinUI objects in your .NET app today.

The WinUI 3 NuGet package has a dependency on the C#/WinRT NuGet package which brings the winrt.runtime.dll library and the cswinrt.exe tool. The cswinrt.exe tool consumes WinMD metadata files that define the WinRT libraries and generates interop .NET 5 and .NET Standard 2.0 C# code. This interop code uses the winrt.runtime.dll library. As you can guess, the cswinrt.exe gets all the WinUI WinMD files and generates C# interop code .NET 5 code for the WinUI library. Then you can compile these files into a .NET library (e.g. using the csc.exe compiler) and use it in every .NET 5 Desktop WinUI application. Fortunately, we already have created this library for you. Itâs the Microsoft.WinUI.dll library. This library is included in the WinUI 3 NuGet Package.

The WinUI NuGet package also has a dependency on the Microsoft.Windows.SDK.NET NuGet package. This package includes the Microsoft.Windows.SDK.NET.dll .NET 5 (and .NET Standard 2.0) interop library that allows use of the other non-WinUI WinRT APIs that are available as part of the Windows 10 OS. Like Microsoft.WinUI.dll, this DLL is generated by C#/WinRT.

Window class and Win32 APIs

With WinUI 3 Preview 1, you can create instances of the Window class in XAML markup. Double click on the MainWindow.xaml file and you will see an example of this:

Code:

<Window
x:Class="HelloWorldDesktopWinUI3CS.MainWindow"
xmlns="http://schemas.microsoft.com/winfx/2...l/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:local="using:HelloWorldDesktopWinUI3CS"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/ma...atibility/2006"
mc:Ignorable="d">

<StackPanel Orientation="Horizontal" HorizontalAlignment="Center" VerticalAlignment="Center">
<Button x:Name="myButton" Click="myButton_Click">Click Me</Button>
</StackPanel>
</Window>
Click to expand...

The XAML Window class was extended to support desktop windows, turning it into an abstraction of the low-level window implementation used by each app model. For instance, the UWP app model uses CoreWindow, while the Win32 app model uses Win32 window handles (HWND). So if youâre building a Desktop WinUI app, you can get the window handle and use Win32 APIs with it.

For example, letâs maximize the Window programmatically using the classic User32 ShowWindow API. To call Win32 APIs from User32.dll you can use the NuGet package PInvoke.User32. Once you have added it, open the code-behind of MainWindow.xaml.cs and add these lines to the button event handler:

Code:

private void myButton_Click(object sender, RoutedEventArgs e)
{
myButton.Content = "Clicked";
IntPtr hwnd = (App.Current as App).MainWindowWindowHandle;
PInvoke.User32.ShowWindow(hwnd, PInvoke.User32.WindowShowStyle.SW_MAXIMIZE);
}
Click to expand...

The ShowWindow method uses the window handle and maximizes it using the second parameter. To get the window handle you can use the GetActiveWindow method that returns the window handle of the current active Window. For example, you can call this method after activating the Window.

The MainWindow object is created, instantiated, and activated in the OnLaunched event that you can find in the App.xaml.cs.

Code:

IntPtr m_windowhandle;
public IntPtr MainWindowWindowHandle { get { return m_windowhandle; } }
protected override void OnLaunched(Microsoft.UI.Xaml.LaunchActivatedEventArgs args)
{
m_window = new MainWindow();
m_window.Activate();
m_windowhandle = PInvoke.User32.GetActiveWindow();
}
Click to expand...

To show the window and the focus you need to call Activate. Easy, right?

Like we did within the Window class, we also extended the Application class to support both UWP and Win32 app models. The Application object is aware of whether the runtime environment is Win32 or UWP, and fires the appropriate application life cycle events. For example, the Resuming event is never fired in Win32 but is in UWP.

Full trust desktop apps

I mentioned earlier that developers want their code to be able to run outside of the security sandbox without any AppContainer â this is called âfull trust permissionâ in the WinRT jargon â and Desktop WinUI 3 allows them to do so. You can call all the .NET 5 APIs without restrictions. For instance, you can query the current process and get a list of its loaded modules; this is something you canât do in the UWP app model. Letâs see how easy it is:

In the MainWindow.xaml create a ContentDialog:

Code:

<StackPanel Orientation="Horizontal" HorizontalAlignment="Center"
VerticalAlignment="Center">
<Button x:Name="myButton" Click="myButton_Click">Click Me</Button>
<ContentDialog x:Name="contentDialog"
Title="Loaded modules"
CloseButtonText="OK">
<ScrollViewer MaxHeight="800">
<TextBlock x:Name="cdTextBlock" TextWrapping="Wrap" />
</ScrollViewer>
</ContentDialog>
</StackPanel>
Click to expand...

And in the code-behind of MainWindow.xaml.cs call the .NET APIs from System.Diagnostics to get the modules loaded in a process:

Code:

private async void myButton_Click(object sender, RoutedEventArgs e)
{
myButton.Content = "Clicked";

var description = new System.Text.StringBuilder();
var process = System.Diagnostics.Process.GetCurrentProcess();
foreach (System.Diagnostics.ProcessModule module in process.Modules)
{
description.AppendLine(module.FileName);
}

cdTextBlock.Text = description.ToString();
contentDialog.XamlRoot = myButton.XamlRoot;
await contentDialog.ShowAsync();

}
Click to expand...

Press F5 to Run and you will get something like this picture when clicking the button:

I have shown you a lot of things with just a few lines of code. .NET with WinUI 3 in Desktop apps allows you to use the .NET APIs as you expect (no limitations) while using WinUI 3 as your UI Framework. Getting access to the underlying window implementation, in this case Win32 and HWNDs, enables you to use the vast set of Win32 APIs in your app in addition to the WinRT APIs of Windows 10. This will allow you to create new Desktop WinUI 3 apps reusing the majority of your current code.

You can get more samples of WinUI 3 in desktop here, and you leave feedback on our Github repo.

Happy WinUI coding devs!
Miguel Ramos â WinUI/XAML PM
Click to expand...

Source: https://blogs.windows.com/windowsdev...-desktop-apps/

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:)

Brink · Jul 7, 2020

Microsoft introduces WinUI 3 Preview 1

Today at Microsoft Build 2020 the WinUI team is excited to announce the latest version of WinUI 3 available for public preview: WinUI 3 Preview 1. This preview expands the world of WinUI to an even wider audience of developers – the previously-released WinUI 3 Alpha was only available to UWP app developers, but Preview 1 now enables WinUI usage in Desktop (Win32) apps as well!

What is WinUI?

WinUI is Microsoft’s most advanced user interface technology for building Windows apps. There are two versions of WinUI in active development: WinUI 2 and WinUI 3. WinUI 2 is a library of Fluent-based UI controls & styles for UWP XAML apps; it was first shipped in Oct 2018 and its latest release is v2.4 which came out recently on May 8th.

WinUI 3 is a currently-in-development, dramatic expansion of this library into a full-fledged, end-to-end, standalone UI framework. This UI framework continues the tradition of WinUI and UWP XAML, providing the very latest graphical capabilities and Fluent Design styling that embraces today’s modern devices, hardware, and inputs. Technically, WinUI 3 decouples the XAML, Composition, and Input layers of Windows 10, and ships them independently via NuGet for any app targeting Windows 10 1803 and above. It can be used in both C++ and .NET-based apps.

WinUI 3 Preview 1 is the first pre-release of WinUI 3 that can be used in both UWP and Desktop apps, allowing every developer a chance to tap into the very latest UI technologies from Microsoft for building Windows apps. You can learn more about WinUI here.

What’s new in WinUI 3 Preview 1?

In addition to the aforementioned ability to use WinUI from Desktop apps, Preview 1 will also support .NET 5 when run in this Desktop context. Preview 1 is also the first preview of WinUI 3 to include the SwapChainPanel control – this is key for developers working with DirectX for providing custom graphical rendering as a part of their user experience.

In February, the WinUI team released an Alpha of WinUI 3 with an all-new Chromium-based WebView2 control. This same control carries through to Preview 1 and has been updated with several improvements. Preview 1 also offers several other advancements compared to the February Alpha:

Support for the .NET versions of several interfaces when using .NET 5. In Preview1, .NET 5 is used with Desktop apps. The interfaces (and a class) are: INotifyPropertyChanged, INotifyCollectionChanged, ObervableCollection<T>, and ICommand.

New, recently released controls ported forward from WinUI v2.4.

Several important bug fixes & stability improvements.

A full articulation of the capabilities and limitations of Preview 1 can be found in the WinUI 3 Preview 1 Release Notes. Of special note: Preview 1 should not be used in production apps, as it does not guarantee forward compatibility and may break in future updates we make to Windows 10.

Who’s using WinUI?

At Build 2020 we’ll share stories of customers and ecosystem partners we’re working with to improve & develop WinUI 3. Examples of these partnerships that will be referenced during the conference include:

Magix, a developer of audio & video solutions for creators, who’s showcasing how they’ve harnessed the power of WinUI to modernize some of the UI components in their Win32-based VEGAS Pro app

Esri, market leader in geographic information system (GIS) software, using ArcGIS Runtime, .NET and SwapChainPanel with WinUI 3 Preview 1 to render gigabytes of geospatial data in rich, high performance mapping components

Telerik, a leading vendor of high quality .NET and JavaScript components for building modern, high performance, feature rich web, mobile and desktop apps

Uno platform, an open source platform for building apps that span across mobile endpoints, Windows, macOS, and the Web

These are just some of the great companies exploring and engaging with us as we develop WinUI 3, and in the coming months you’ll learn more about these and other engagements as we prepare for the eventual release of WinUI 3.0 for general availability.

How can I get started?

To start with WinUI 3.0 Preview 1, head over to our download and release notes page. You can also find more information and technical setup details in our documentation on creating a Desktop app with WinUI.
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Source: https://blogs.windows.com/windowsdev...i-3-preview-1/

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Brink · Jul 7, 2020

Announcing Open Source of WPF, Windows Forms, and WinUI

At Build 2018, I outlined our approach to helping you be more productive when developing apps, including the introduction of .NET Core 3.0. We also started decoupling many parts of the Windows development platform, so you can adopt technologies incrementally. Today at Microsoft Connect(); 2018 Conference we shared the next steps – specifically to support innovations in UI:

.NET Core 3.0 Preview 1 adds support for building client apps using Windows Presentation Foundation (WPF), Windows Forms, and XAML Islands.

WPF, Windows Forms, and Windows UI XAML Library (WinUI) are now open source, so you can create experiences with the freedom you want.

.NET Core 3.0 Preview 1 available

As Scott Guthrie announced today, the first preview of .NET Core 3.0 is available. This version of .NET adds support for building Windows desktop apps using WPF and Windows Forms. You will now be able to:

Run multiple instances of .NET Core 3.0 side-by-side on the same computer so you can update WPF and Windows Forms apps to a new version of .NET without updating the entire OS.

Use modern controls and Fluent styling from the WinUI XAML Library via XAML Islands from .NET Core 3.0 apps.

Read about .NET Core 3.0 Preview 1, try out the preview, and give us feedback. The next version of the .NET Framework, .NET Framework 4.8, will include new controls that use the latest browser and media players in Windows 10, support the latest standards, and WPF and Windows Forms apps will have access to WinUI via XAML Islands for modern look and touch support. The .NET Team blog details the differences and compatibility between .NET Core and .NET Framework moving forward.

WPF, Windows Forms, and WinUI ready for your contributions

This journey is our continued commitment to creating the development platform with you, through open source. Our three, popular Windows UX frameworks are ready for your contributions on GitHub: WPF, Windows Forms, and WinUI. Open sourcing these technologies provides transparency between the product team and the community, helps democratize Windows development, and enables the community to engage and contribute to these repos.

We look forward to your contributions. You can get started with Windows Forms and WinUI now. WPF is starting with System.Xaml, with more to come over the following months.
Click to expand...

Source: Announcing Open Source of WPF, Windows Forms, and WinUI at Microsoft Connect(); 2018 - Windows Developer Blog

See also: .NET Core 3 Preview 1 and Open Source Windows Desktop Frameworks - Windows 10 Forums

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Brink · Jul 7, 2020

Announcing Open Source of WPF, Windows Forms, and WinUI

At Build 2018, I outlined our approach to helping you be more productive when developing apps, including the introduction of .NET Core 3.0. We also started decoupling many parts of the Windows development platform, so you can adopt technologies incrementally. Today at Microsoft Connect(); 2018 Conference we shared the next steps – specifically to support innovations in UI:

.NET Core 3.0 Preview 1 adds support for building client apps using Windows Presentation Foundation (WPF), Windows Forms, and XAML Islands.

WPF, Windows Forms, and Windows UI XAML Library (WinUI) are now open source, so you can create experiences with the freedom you want.

.NET Core 3.0 Preview 1 available

As Scott Guthrie announced today, the first preview of .NET Core 3.0 is available. This version of .NET adds support for building Windows desktop apps using WPF and Windows Forms. You will now be able to:

Run multiple instances of .NET Core 3.0 side-by-side on the same computer so you can update WPF and Windows Forms apps to a new version of .NET without updating the entire OS.

Use modern controls and Fluent styling from the WinUI XAML Library via XAML Islands from .NET Core 3.0 apps.

Read about .NET Core 3.0 Preview 1, try out the preview, and give us feedback. The next version of the .NET Framework, .NET Framework 4.8, will include new controls that use the latest browser and media players in Windows 10, support the latest standards, and WPF and Windows Forms apps will have access to WinUI via XAML Islands for modern look and touch support. The .NET Team blog details the differences and compatibility between .NET Core and .NET Framework moving forward.

WPF, Windows Forms, and WinUI ready for your contributions

This journey is our continued commitment to creating the development platform with you, through open source. Our three, popular Windows UX frameworks are ready for your contributions on GitHub: WPF, Windows Forms, and WinUI. Open sourcing these technologies provides transparency between the product team and the community, helps democratize Windows development, and enables the community to engage and contribute to these repos.

We look forward to your contributions. You can get started with Windows Forms and WinUI now. WPF is starting with System.Xaml, with more to come over the following months.
Click to expand...

Source: Announcing Open Source of WPF, Windows Forms, and WinUI at Microsoft Connect(); 2018 - Windows Developer Blog

See also: .NET Core 3 Preview 1 and Open Source Windows Desktop Frameworks - Windows 10 Forums

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Windows 10: A deep-dive into WinUI 3 in desktop apps for Windows 10

A deep-dive into WinUI 3 in desktop apps for Windows 10

A deep-dive into WinUI 3 in desktop apps for Windows 10

A deep-dive into WinUI 3 in desktop apps for Windows 10

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