Using Forms as Child Controls

Any object that inherits from the Control class may be used as a child control of a ToolWindow or DocumentWindow.

This code shows how to add a control to a ToolWindow and make it the available area within the ToolWindow:

// Assume that toolWindow is already referencing a tool window
TextBox tb = new TextBox();
tb.Dock = DockStyle.Fill;
toolWindow.Controls.Add(tb);

When the child control is a Form, several extra steps need to be taken. By default, normal Control-based objects are visible while Form-based objects are not. Form-based objects cannot be parented to other Controls until the Form.TopLevel property has been set to false. Also, Form objects will continue to show their border unless you turn it off.

Keeping these issues in mind, the above code must be changed to the following to support a Form as a child control:

// Assume that toolWindow is already referencing a tool window
Form f = new Form();
f.Visible = true;
f.TopLevel = false;
f.FormBorderStyle = FormBorderStyle.None;
f.Dock = DockStyle.Fill;
toolWindow.Controls.Add(f);