Using the Toolbox
The Toolbox is a sliding tree control that behaves much like Windows Explorer, but without grid or connection lines. Multiple segments of the Toolbox (called "tabs") can be expanded simultaneously, and the entire tree scrolls inside the Toolbox window. To expand any tab of the Toolbox, click the plus (+) sign next to its name. To collapse an expanded tab, click the minus (-) sign next to its name.
The Toolbox displays icons for items that you can add to projects. Each time you return to an editor or designer, the Toolbox automatically scrolls to the tab and item most recently selected. As you shift focus to a different editor or designer or to a different project, the current selection in the Toolbox shifts with you.
The Toolbox only displays items appropriate to the type of file you are working in. In an HTML page, for example, only the HTML and General tabs are available. In a Windows Form, every category of Windows Forms controls is displayed. No Toolbox items are displayed while editing Console applications, because they are typically designed without a graphical user interface., and on the target .NET Framework version.
The collection of available controls also depends on the .NET Framework version your project targets. By default, Visual Studio 2010 projects target the .NET Framework 4 Client Profile. This reduces the size of deployment packages by not requiring the entire .NET Framework for installation. If your project requires a control that is not supported by the Client Profile, you can set your project to target .NET Framework 4 by editing the project properties.
You can customize the Toolbox by rearranging items within a tab or adding custom tabs and items. For more information, see How to: Manage the Toolbox Window and How to: Manipulate Toolbox Tabs. To add or remove Toolbox items, use the Choose Toolbox Items Dialog Box (Visual Studio). Items that can be made available as Toolbox icons include components from the .NET Framework class library, COM components, controls for Windows Forms and Web Forms, HTML elements, and XML namespaces.
The actual component files on your computer are not affected when you add or remove icons from the Toolbox.
When you choose a different settings combination, the current Toolbox state is cleared. Choosing a different settings combination can change which Toolbox tabs are now available, and what items are displayed on a tab. For more information, see Working with Settings.