Windows Runtime components

A Windows Runtime component is a self-contained software module that you can author, reference, and use with any Windows Runtime language (including C#, C++/WinRT, Visual Basic, JavaScript, and C++/CX). You can use Visual Studio to create a Windows Runtime component that can be consumed by either an app that uses the Windows App SDK or by a Universal Windows Platform (UWP) app.

Note

For C++ developers, we recommend that you use C++/WinRT for new applications. C++/WinRT is an entirely standard modern C++17 language projection for Windows Runtime (WinRT) APIs, implemented as a header-file-based library, and designed to provide you with first-class access to the modern Windows API. To learn how to create a Windows Runtime component using C++/WinRT, see Windows Runtime components with C++/WinRT.

Note

For C# developers writing desktop apps in .NET 6 or later, use C#/WinRT to author a Windows Runtime component. See Author Windows Runtime components with C#/WinRT.

Topic	Description
Windows Runtime components with C++/WinRT	This topic shows how to use C++/WinRT to create and consume a Windows Runtime component—a component that's callable from a Universal Windows app built using any Windows Runtime language.
Windows Runtime components with C++/CX	This topic shows how to use C++/CX to create a Windows Runtime component—a component that's callable from a Universal Windows app built using any Windows Runtime language.
Walkthrough of creating a C++/CX Windows Runtime component, and calling it from JavaScript or C#	This walkthrough shows how to create a basic Windows Runtime component DLL that's callable from JavaScript, C#, or Visual Basic. Before you begin this walkthrough, make sure that you understand concepts such as the Abstract Binary Interface (ABI), ref classes, and the Visual C++ Component Extensions that make working with ref classes easier. For more information, see Creating Windows Runtime components in C++ and Visual C++ Language Reference (C++/CX).
Windows Runtime components with C# and Visual Basic	You can use managed code to create your own Windows Runtime types, packaged in a Windows Runtime component. You can use your component in Universal Windows Platform (UWP) apps with C++, JavaScript, Visual Basic, or C#. This topic outlines the rules for creating a component, and discusses some aspects of .NET support for the Windows Runtime. In general, that support is designed to be transparent to the .NET programmer. However, when you create a component to use with JavaScript or C++, you need to be aware of differences in the way those languages support the Windows Runtime.
Walkthrough of creating a C# or Visual Basic Windows Runtime component, and calling it from JavaScript	This walkthrough shows how you can use .NET with Visual Basic or C# to create your own Windows Runtime types, packaged in a Windows Runtime component, and how to call the component from your Universal Windows app built for Windows using JavaScript.
Raising Events in Windows Runtime components	If your Windows Runtime component raises an event of a user-defined delegate type on a background thread (worker thread) and you want JavaScript to be able to receive the event, you can implement and/or raise it in one of these ways: