Windows Forms (WinForms) is a free and open-source graphical (GUI)

class library In computer science, a library is a collection of non-volatile resources used by computer programs, often for software development. These may include configuration data, documentation, help data, message templates, pre-written code and subro ...

included as a part of

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washin ...

.NET,

.NET Framework The .NET Framework (pronounced as "''dot net"'') is a proprietary software framework developed by Microsoft that runs primarily on Microsoft Windows. It was the predominant implementation of the Common Language Infrastructure (CLI) until bein ...

Mono Framework Mono is a free and open-source .NET Framework-compatible software framework. Originally by Ximian, it was later acquired by Novell, and is now being led by Xamarin, a subsidiary of Microsoft and the .NET Foundation. Mono can be run on many softwa ...

, providing a platform to write client applications for desktop, laptop, and tablet PCs. While it is seen as a replacement for the earlier and more complex

C++ C++ (pronounced "C plus plus") is a high-level general-purpose programming language created by Danish computer scientist Bjarne Stroustrup as an extension of the C programming language, or "C with Classes". The language has expanded significan ...

based

Microsoft Foundation Class Library Microsoft Foundation Class Library (MFC) is a C++ object-oriented library for developing desktop applications for Windows. MFC was introduced by Microsoft in 1992 and quickly gained widespread use. While Microsoft has introduced alternative app ...

, it does not offer a comparable paradigm and only acts as a platform for the user interface tier in a multi-tier solution. At the Microsoft Connect event on December 4, 2018,

announced releasing Windows Forms as an open source project on

GitHub GitHub, Inc. () is an Internet hosting service for software development and version control using Git. It provides the distributed version control of Git plus access control, bug tracking, software feature requests, task management, continu ...

. It is released under the

MIT License The MIT License is a permissive free software license originating at the Massachusetts Institute of Technology (MIT) in the late 1980s. As a permissive license, it puts only very limited restriction on reuse and has, therefore, high license comp ...

. With this release, Windows Forms has become available for projects targeting the

.NET Core The domain name net is a generic top-level domain (gTLD) used in the Domain Name System of the Internet. The name is derived from the word ''network'', indicating it was originally intended for organizations involved in networking technologies ...

framework. However, the framework is still available only on the Windows platform, and Mono's incomplete implementation of Windows Forms remains the only cross-platform implementation.

Architecture

A ''Windows Forms application'' is an event-driven application supported by Microsoft's

. Unlike a batch program, it spends most of its time simply waiting for the user to do something, such as fill in a text box or click a

button A button is a fastener that joins two pieces of fabric together by slipping through a loop or by sliding through a buttonhole. In modern clothing and fashion design, buttons are commonly made of plastic but also may be made of metal, wood, o ...

. The code for the application can be written in a .NET programming language such as C# or

Visual Basic Visual Basic is a name for a family of programming languages from Microsoft. It may refer to: * Visual Basic .NET (now simply referred to as "Visual Basic"), the current version of Visual Basic launched in 2002 which runs on .NET * Visual Basic ( ...

. Windows Forms provides access to native Windows User Interface Common Controls by wrapping the existent

Windows API The Windows API, informally WinAPI, is Microsoft's core set of application programming interfaces (APIs) available in the Microsoft Windows operating systems. The name Windows API collectively refers to several different platform implementations th ...

in managed code. With the help of Windows Forms, the .NET Framework provides a more comprehensive abstraction above the Win32 API than Visual Basic or MFC did. Windows Forms is similar to Microsoft Foundation Class (MFC) library in developing client applications. It provides a wrapper consisting of a set of C++ classes for development of Windows applications. However, it does not provide a default application framework like the MFC. Every control in a Windows Forms application is a concrete instance of a class.

Features

All visual elements in the Windows Forms class library derive from the Control class. This provides the minimal functionality of a user interface element such as location, size, color, font, text, as well as common events like click and drag/drop. The Control class also has docking support to let a control rearrange its position under its parent. The

Microsoft Active Accessibility Microsoft Active Accessibility (MSAA) is an application programming interface (API) for user interface accessibility. MSAA was introduced as a platform add-on to Microsoft Windows 95 in 1997. MSAA is designed to help Assistive Technology (AT) produ ...

support in the Control class also helps impaired users to use Windows Forms better. Besides providing access to native Windows controls like button, textbox, checkbox and listview, Windows Forms added its own controls for

ActiveX ActiveX is a deprecated software framework created by Microsoft that adapts its earlier Component Object Model (COM) and Object Linking and Embedding (OLE) technologies for content downloaded from a network, particularly from the World Wide We ...

hosting, layout arrangement, validation and rich data binding. Those controls are rendered using

GDI GDI may refer to: Science and technology * Gasoline direct injection, a type of fuel injection * Graphics Device Interface, a component of Microsoft Windows * Guanosine nucleotide dissociation inhibitor, a protein Organisations * Gabriel Dumont I ...

History and future

Just like

Abstract Window Toolkit The Abstract Window Toolkit (AWT) is Java's original platform-dependent windowing, graphics, and user-interface widget toolkit, preceding Swing. The AWT is part of the Java Foundation Classes (JFC) — the standard API for providing a graphi ...

(AWT), the equivalent

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's mos ...

API, Windows Forms was an early and easy way to provide

graphical user interface The GUI ( "UI" by itself is still usually pronounced . or ), graphical user interface, is a form of user interface that allows users to interact with electronic devices through graphical icons and audio indicator such as primary notation, inst ...

components to the

. Windows Forms is built on the existing Windows API and some controls merely wrap underlying Windows components. Some of the methods allow direct access to Win32 callbacks, which are not available in non-Windows platforms. In .NET Framework 2.0, Windows Forms gained richer layout controls, Office 2003 style toolstrip controls, multithreading component, richer design-time and data binding support as well as

ClickOnce ClickOnce is a component of Microsoft .NET Framework 2.0 and later, and supports deploying applications made with Windows Forms or Windows Presentation Foundation. It is similar to Java Web Start for the Java Platform or Zero Install for Linux. ...

for web-based deployment. With the release of .NET 3.0, Microsoft released a second, parallel API for rendering GUIs:

Windows Presentation Foundation Windows Presentation Foundation (WPF) is a free and open-source graphical subsystem (similar to WinForms) originally developed by Microsoft for rendering user interfaces in Windows-based applications. WPF, previously known as "Avalon", was initia ...

(WPF) based on DirectX, together with a GUI declarative language called

XAML Extensible Application Markup Language (XAML ) is a declarative XML-based language that Microsoft developed for initializing structured values and objects. It is available under Microsoft's Open Specification Promise. XAML is used extensively ...

. During a question-and-answer session at the Build 2014 Conference, Microsoft explained that Windows Forms was under maintenance mode, with no new features being added, but bugs found would still be fixed. Most recently, improved high-DPI support for various Windows Forms controls was introduced in updates to .NET Framework version 4.5. Microsoft unexplainedly and unexpectedly removed Windows Forms for Visual C++ from the template options and New Item menus in Visual Studio. Windows Forms continue to be available as templates and New Items for the other .NET languages C# and Visual Basic. There is no explanation in Microsoft Documentation for the decision to remove Windows Forms for Visual C++ from templates and New Item menus in Visual Studio. The Visual Studio Designer still supports Visual C++ Windows Forms for manually created Windows Forms classes. It is unclear why Microsoft made this decision.

XAML backwards compatibility with Windows Forms

For future development, Microsoft has succeeded Windows Forms with an

-based GUI entry using frameworks such as WPF and UWP. However, drag and drop placement of GUI components in a manner similar to Windows Forms is still provided in XAML by replacing the root XAML element of the Page/Window with a "Canvas" UI-Control. When making this change, the user can build a window in a similar fashion as in Windows Forms by directly dragging and dropping components using the Visual Studio GUI. While XAML provides drag and drop placement backwards compatibility through the Canvas Control, XAML Controls are only similar to Windows Forms Controls and are not one-to-one backwards compatible. They perform similar functions and have a similar appearance, but the properties and methods are different enough to require remapping from one API to another.

Alternative implementation

Mono is a project led by Xamarin (formerly by

Ximian Ximian, Inc. (previously called Helix Code and originally named International Gnome Support) was an American company that developed, sold and supported application software for Linux and Unix based on the GNOME platform. It was founded by Migu ...

, then Novell) to create an Ecma standard compliant

compatible set of tools. In 2011, Mono's support for System.Windows.Forms as of .NET 2.0 was announced as complete; System.Windows.Forms 2.0 works natively on Mac OS X. However, System.Windows.Forms has not been actively developed on Mono. Full compatibility with .NET was not possible, because Microsoft's System.Windows Forms is mainly a wrapper around the

, and some of the methods allow direct access to Win32 callbacks, which are not available in platforms other than Windows. A more significant problem is that, since version 5.2, Mono has been upgraded so that its default is to assume a 64 bit platform. However, System.Windows.Forms on Mono for the Macintosh OS X platform has been built using a 32 bit subsystem,

Carbon Carbon () is a chemical element with the symbol C and atomic number 6. It is nonmetallic and tetravalent—its atom making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. Carbon mak ...

. As of this date, a 64-bit version of System.Windows.Forms for use on Mac OS X remains unavailable and only .NET applications built for the 32 bit platform can be expected to execute.

References

External links

MSDN: Building Windows Forms applications

MSDN : Windows.Forms reference documentation

MSDN : Windows Forms Technical Articles - Automating Windows Form with Visual Test
{{Widget toolkits .NET terminology Formerly proprietary software Free and open-source software

Forms Form is the shape, visual appearance, or configuration of an object. In a wider sense, the form is the way something happens. Form also refers to: *Form (document), a document (printed or electronic) with spaces in which to write or enter data * ...

Microsoft free software Mono (software) Software using the MIT license Widget toolkits 2002 software Windows-only free software