MaskedTextBox.HidePromptOnLeave Property     
Definition
Important
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Gets or sets a value indicating whether the prompt characters in the input mask are hidden when the masked text box loses focus.
public:
 property bool HidePromptOnLeave { bool get(); void set(bool value); };
	public bool HidePromptOnLeave { get; set; }
	member this.HidePromptOnLeave : bool with get, set
	Public Property HidePromptOnLeave As Boolean
	Property Value
true if PromptChar is hidden when MaskedTextBox does not have focus; otherwise, false. The default is false.