winforms

# Windows Forms

[![License: MIT](https://img.shields.io/badge/License-MIT-green.svg)](https://github.com/dotnet/winforms/blob/main/LICENSE.TXT)

Windows Forms (WinForms) is a UI framework for building Windows desktop applications. It is a .NET wrapper over Windows user interface libraries, such as User32 and GDI+. It also offers controls and other functionality that is unique to Windows Forms.

Windows Forms also provides one of the most productive ways to create desktop applications based on the visual designer provided in Visual Studio. It enables drag-and-drop of visual controls and other similar functionality that make it easy to build desktop applications.

## Windows Forms Out-Of-Process Designer

For information about the WinForms Designer supporting the .NET runtime and the changes between the .NET Framework Designer (supporting .NET Framework up to version 4.8.1) vs. the .NET Designer (supporting .NET 6, 7, 8, 9+), please see [Windows Forms Designer Documentation](https://learn.microsoft.com/dotnet/desktop/winforms/controls-design/designer-differences-framework?view=netdesktop-8.0).

**Important:** As a Third Party Control Vendor, when you migrate controls from .NET Framework to .NET, your control libraries _at runtime_ are expected to work as before in the context of the respective new TFM (special modernization or security changes in the TFM kept aside, but those are rare breaking changes). Depending on the richness of your control's design-time support, the migration of control designers from .NET Framework to .NET might need to take a series of areas with breaking changes into account. The provided link points out additional resources which help in that migration process.

## Relationship to .NET Framework

This codebase is a fork of the Windows Forms code in the .NET Framework 4.8. 
We started the migration process by targeting .NET Core 3.0, when we've strived to bring the two runtimes to a parity. Since then, we've done a number of changes, including [breaking changes](https://docs.microsoft.com/dotnet/core/compatibility/winforms), which diverged the two. For more information about breaking changes, see the [Porting guide][porting-guidelines].

## The bar for innovation and new features

WinForms is a technology which was originally introduced as a part of .NET Framework 1.0 on February 13th, 2002. It's primary focus was and is to be a Rapid Application Tool for Windows based Apps, and that principal sentiment has not changed over the years. WinForms at the time addressed developer's requests for

* A framework for stable, monolithic Line of Business Apps, even with extremely complicated and complex domain-specific workflows
* The ability to easily provide rich user interfaces
* A safe and - over the first 3 versions of .NET Framework - increasingly performant way to communicate across process boundaries via various Windows Communication Services, or access on-site databases via ADO.NET providers.
* A very easy to use, visual wha