ToolStripControlHost is the abstract base class for ToolStripComboBox, ToolStripTextBox, and ToolStripProgressBar. ToolStripControlHost can host other controls, including custom controls, in two ways:
Construct a ToolStripControlHost with a class that derives from Control. To fully access the hosted control and properties, you must cast the Control property back to the actual class it represents.
Extend ToolStripControlHost, and in the inherited class's default constructor, call the base class constructor passing a class that derives from Control. This option lets you wrap common control methods and properties for easy access in a ToolStrip.
Use the ToolStripControlHost class to host your customized controls or any other Windows Forms control.
To customize a ToolStripItem, derive from ToolStripControlHost and create a custom implementation. You can override methods such as OnSubscribeControlEvents to handle events raised by the hosted controls, and you can put custom functionality into properties to enhance the hosted control.