Toolbox, Components tab
Applies to: 
Visual Studio 
Visual Studio for Mac
Note
This article applies to Visual Studio 2017. If you're looking for the latest Visual Studio documentation, see Visual Studio documentation. We recommend upgrading to the latest version of Visual Studio. Download it here
Displays components you can add to Visual Basic and C# designers for Windows Forms. In addition to the .NET components that are included with Visual Studio, such as the MessageQueue and EventLog components, you can add your own or third-party components to this tab.
To display this tab, open a Windows Forms designer. Select View > Toolbox. In Toolbox, select the Components tab.
Components
BackgroundWorker
Creates a BackgroundWorker component instance that can run an operation on a separate, dedicated thread. For more information, see BackgroundWorker component.
DirectoryEntry
Creates a DirectoryEntry component instance that encapsulates a node or object in the Active Directory hierarchy and can be used to interact with Active Directory service providers.
DirectorySearcher
Creates a DirectorySearcher component instance that you can use to perform queries against the Active Directory.
ErrorProvider
Creates a ErrorProvider component instance, which indicates to the end user that a control on a form has an error associated with it. For more information, see ErrorProvider component.
EventLog
Creates an EventLog component instance you can use to interact with system and custom event logs, including writing events to a log and reading log data.
FileSystemWatcher
Creates a FileSystemWatcher component instance that you can use to monitor for changes to any directory or file to which you have access.
HelpProvider
Creates a HelpProvider component instance that provides pop-up or online help for controls. For more information, see HelpProvider component.
ImageList
Creates a ImageList component instance that provides methods to manage a collection of Image objects. For more information, see ImageList component.
MessageQueue
Creates a MessageQueue component instance that you can use to interact with message queues, including reading messages from and writing messages to queues, processing transactions, and performing queue administration tasks.
PerformanceCounter
Creates a PerformanceCounter component instance that you can use to interact with Windows performance counters, including creating new categories and instances, reading values from counters, and performing calculations on counter data.
Process
Creates a Process component instance you can use to stop, start, and manipulate the data associated with processes on your system.
SerialPort
Creates a SerialPort component instance that provides synchronous and event-driven I/O, access to pin and break states, and access to serial driver properties.
ServiceController
Creates a ServiceController component instance you can use to manipulate existing services, including starting and stopping services and sending commands to them.
Timer
Creates a Timer component instance you can use to add time-based functionality to your Windows-based applications. For more information, see Timer component.
Note
There is also a system-based Timer that you can add to the Toolbox This Timer is optimized for server applications, and the Windows Forms Timer is best suited for use on Windows Forms.