Visual Studio provides several different types of windows, for example tool windows, document windows, and dialog windows. Other windows such as the Properties window, the Output window, and the Task List window, are types of tool windows.
Tool windows
Visual Studio tool windows are usually read-only windows that are not file-based. In this they differ from document windows, which display files in read-write mode. The Toolbox, Solution Explorer, Properties window, and Web Browser are examples of tool windows.
To find out how to create a simple tool window, see Add a tool window.
Tool windows are single-instance by default, meaning that only one instance of the tool window can be open at a time. After a single-instance tool window is opened, it remains open until the IDE is closed. When you close a single-instance tool window, only its visibility changes. You can also create multi-instance tool windows, such that multiple instances of the window can be open simultaneously. See Create a multi-instance tool window for more information.
Tool windows can be dynamic, meaning that they are visible whenever their related UI context applies. The use of auto-visibility can reduce the clutter of windows in the IDE. For more information, see Open a dynamic tool window.
Tool windows can be docked, floating, or tabbed in the document frame. The tool window frame is provided by the IDE and is used to control the size, location, docking state, and other persistent properties. The tool window pane displays the contents. The default size and location apply only when the tool window is first opened; after that the tool window state is persisted.
Tool window panes can host WPF user controls and support toolbars. You can override the Window property to return the handle of the hosted control.
Finance and operations apps are customized by using extensions, which let you add functionality to model elements and source code in the Application Object Tree (AOT) by using Visual Studio.