Windows Forms Overview

The following overview discusses the advantages of smart client applications, the main features of Windows Forms programming, and how you can use Windows Forms to build smart clients that meet the needs of today's enterprises and end users.

Windows Forms and Smart Client Applications

With Windows Forms you develop smart clients. Smart clients are graphically rich applications that are easy to deploy and update, can work when they are connected to or disconnected from the Internet, and can access resources on the local computer in a more secure manner than traditional Windows-based applications.

Building Rich, Interactive User Interfaces

Windows Forms is a smart client technology for the .NET Framework, a set of managed libraries that simplify common application tasks such as reading and writing to the file system. When you use a development environment like Visual Studio, you can create Windows Forms smart-client applications that display information, request input from users, and communicate with remote computers over a network.

In Windows Forms, a form is a visual surface on which you display information to the user. You ordinarily build Windows Forms applications by adding controls to forms and developing responses to user actions, such as mouse clicks or key presses. A control is a discrete user interface (UI) element that displays data or accepts data input.

When a user does something to your form or one of its controls, the action generates an event. Your application reacts to these events by using code, and processes the events when they occur. For more information, see Creating Event Handlers in Windows Forms.

Windows Forms contains a variety of controls that you can add to forms: controls that display text boxes, buttons, drop-down boxes, radio buttons, and even Web pages. For a list of all the controls you can use on a form, see Controls to Use on Windows Forms. If an existing control does not meet your needs, Windows Forms also supports creating your own custom controls using the UserControl class.

Windows Forms has rich UI controls that emulate features in high-end applications like Microsoft Office. When you use the ToolStrip and MenuStrip control, you can create toolbars and menus that contain text and images, display submenus, and host other controls such as text boxes and combo boxes.

With the Visual Studio drag-and-drop Windows Forms Designer, you can easily create Windows Forms applications. Just select the controls with your cursor and add them where you want on the form. The designer provides tools such as gridlines and snap lines to take the hassle out of aligning controls. And whether you use Visual Studio or compile at the command line, you can use the FlowLayoutPanel, TableLayoutPanel and SplitContainer controls to create advanced form layouts in less time.

Finally, if you must create your own custom UI elements, the System.Drawing namespace contains a large selection of classes to render lines, circles, and other shapes directly on a form.


Windows Forms controls are not designed to be marshaled across application domains. For this reason, Microsoft does not support passing a Windows Forms control across an AppDomain boundary, even though the Control base type of MarshalByRefObject would seem to indicate that this is possible. Windows Forms applications that have multiple application domains are supported as long as no Windows Forms controls are passed across application domain boundaries.

Help Creating Forms and Controls

For step-by-step information about how to use these features, see the following Help topics.


Help topic

Creating a new Windows Forms application with Visual Studio

Walkthrough: Creating a Simple Windows Form

Using controls on forms

How to: Add Controls to Windows Forms

Handling events from a form and the forms' controls

How to: Create Event Handlers Using the Designer

Using the ToolStrip Control

How to: Create a Basic Windows Forms ToolStrip with Standard Items Using the Designer

Creating graphics with System.Drawing

Getting Started with Graphics Programming

Creating custom controls

How to: Inherit from the UserControl Class

Displaying and Manipulating Data

Many applications must display data from a database, XML file, XML Web service, or other data source. Windows Forms provides a flexible control that is named the DataGridView control for displaying such tabular data in a traditional row and column format, so that every piece of data occupies its own cell. When you use DataGridView, you can customize the appearance of individual cells, lock arbitrary rows and columns in place, and display complex controls inside cells, among other features.

Connecting to data sources over a network is a simple task with Windows Forms smart clients. The BindingSource component, new with Windows Forms in Visual Studio 2005 and the .NET Framework 2.0, represents a connection to a data source, and exposes methods for binding data to controls, navigating to the previous and next records, editing records, and saving changes back to the original source. The BindingNavigator control provides a simple interface over the BindingSource component for users to navigate between records.

You can create data-bound controls easily by using the Data Sources window. The window displays data sources such as databases, Web services, and objects in your project. You can create data-bound controls by dragging items from this window onto forms in your project. You can also data-bind existing controls to data by dragging objects from the Data Sources window onto existing controls.

Another type of data binding you can manage in Windows Forms is settings. Most smart client applications must retain some information about their run-time state, such as the last-known size of forms, and retain user preference data, such as default locations for saved files. The Application Settings feature addresses these requirements by providing an easy way to store both types of settings on the client computer. After you define these settings by using either Visual Studio or a code editor, the settings are persisted as XML and automatically read back into memory at run time.

Help Displaying and Manipulating Data

For step-by-step information about how to use these features, see the following Help topics.


Help topic

Using the BindingSource component

How to: Bind Windows Forms Controls with the BindingSource Component Using the Designer

Working with ADO.NET data sources

How to: Sort and Filter ADO.NET Data with the Windows Forms BindingSource Component

Using the Data Sources window

Walkthrough: Displaying Data on a Form in a Windows Application

Using application settings

How to: Create Application Settings Using the Designer

How to: Create Application Settings

Deploying Applications to Client Computers

After you have written your application, you must send the application to your users so that they can install and run it on their own client computers. When you use the ClickOnce technology, you can deploy your applications from within Visual Studio by using just a few clicks, and provide your users with a URL pointing to your application on the Web. ClickOnce manages all the elements and dependencies in your application, and ensures that the application is correctly installed on the client computer.

ClickOnce applications can be configured to run only when the user is connected to the network, or to run both online and offline. When you specify that an application should support offline operation, ClickOnce adds a link to your application in the user's Start menu. The user can then open the application without using the URL.

When you update your application, you publish a new deployment manifest and a new copy of your application to your Web server. ClickOnce will detect that there is an update available and upgrade the user's installation; no custom programming is required to update old assemblies.

Help Deploying ClickOnce Applications

For a full introduction to ClickOnce, see ClickOnce Deployment Overview. For step-by-step information about how to use these features, see the following Help topics,


Help topic

Deploying an application by using ClickOnce

How to: Publish a ClickOnce Application

Walkthrough: Manually Deploying a ClickOnce Application

Updating a ClickOnce deployment

How to: Manage Updates for a ClickOnce Application

Managing security with ClickOnce

How to: Enable ClickOnce Security Settings

Other Controls and Features

There are many other features in Windows Forms that make implementing common tasks fast and easy, such as support for creating dialog boxes, printing, adding Help and documentation, and localizing your application to multiple languages. Additionally, Windows Forms relies on the robust security system of the .NET Framework. With this system, you can release more secure applications to your customers.

Help Implementing Other Controls and Features

For step-by-step information about how to use these features, see the following Help topics.


Help topic

Printing the contents of a form

How to: Print Graphics in Windows Forms

How to: Print a Multi-Page Text File in Windows Forms

Globalizing a Windows Forms application

Walkthrough: Localizing Windows Forms

Learn more about Windows Forms security

Security in Windows Forms Overview

See Also


Walkthrough: Creating a Simple Windows Form


Additions to Windows Forms for the .NET Framework 2.0

Application Settings Overview

ClickOnce Deployment Overview


ToolStrip Control Overview (Windows Forms)

DataGridView Control Overview (Windows Forms)

BindingSource Component Overview

Other Resources

Getting Started with Windows Forms

Creating a New Windows Form