[DesignerGeneratedAttribute]
[EditorBrowsableAttribute(EditorBrowsableState.Advanced)]
public class MessageBoxForm : Form

<DesignerGeneratedAttribute> _
<EditorBrowsableAttribute(EditorBrowsableState.Advanced)> _
Public Class MessageBoxForm _
	Inherits Form

[DesignerGeneratedAttribute]
[EditorBrowsableAttribute(EditorBrowsableState::Advanced)]
public ref class MessageBoxForm : public Form

[<DesignerGeneratedAttribute>]
[<EditorBrowsableAttribute(EditorBrowsableState.Advanced)>]
type MessageBoxForm =  
    class
        inherit Form
    end

public class MessageBoxForm extends Form

This class implements MessageBox in fully dynamic way. You can change all it's properties and all properties of its controls and those change are immediatelly displayed to user.

If you are passing some very custom implementation of MessageBox to this form, you must ensure that : Argument e of the ComboBox.Items.CollectionChanged event has always Action which is member of CollectionChangeAction.Argument e of the ButtonsChanged and RadiosChanged events has always Action which is member of CollectionChangeAction and is not Other. Violating these rules can lead to uncatchable InvalidOperationException being thrown when event occurs.

System..::..Object
  System..::..MarshalByRefObject
    System.ComponentModel..::..Component
      System.Windows.Forms..::..Control
        System.Windows.Forms..::..ScrollableControl
          System.Windows.Forms..::..ContainerControl
            System.Windows.Forms..::..Form
              Tools.WindowsT.FormsT..::..MessageBoxForm