Gets or sets whether the check editor supports three check states. This is a dependency property.
true if the check editor supports three check states; otherwise, false.
If the IsThreeState property is set to false, only two states - Unchecked and Checked are available.
If the IsThreeState property is true, a check editor can take one of the three check states: Unchecked, Checked and Indeterminate. In the indeterminate (also called "grayed") state, the editor's check box is displayed with a dimmed appearance to indicate that the option is unavailable. You can handle the CheckEdit.Indeterminate event to respond to setting the check editor to the Indeterminate state.