.NET Framework 4.6 and 4.5
Gets a value indicating whether the user can undo the previous operation. This property is not supported by MaskedTextBox.
Public ReadOnly Property CanUndo As Boolean
The CanUndo property is inherited from the base TextBoxBase class. However, because MaskedTextBox does not support undo functionality, this property always has a value of false.
Supported in: 4.6, 4.5, 4, 3.5, 3.0, 2.0
.NET Framework Client Profile
Supported in: 4, 3.5 SP1