title: how to delete or hide placeholder when there is no value
body: <p>i want to ask if input text in row cell that has mask it will show as <code>1234-5678-9123-456</code>. and when i try to delete the value why does it still showing the place holder ? <code>-    -    -    -</code> how do i delete/hide the place holder ? but when i try to delete it with <code>CTRL+DEL</code> it's totally empty the cell value.</p>
  
  <pre><code>    Dim x As New Repository.RepositoryItemTextEdit
  
      x.Mask.MaskType = Mask.MaskType.Simple
      x.Mask.EditMask = "9999-9999-9999-9999"
      x.Mask.PlaceHolder = " " 
      x.AllowNullInput = DevExpress.Utils.DefaultBoolean.True
      x.NullValuePrompt = ""
      x.NullValuePromptShowForEmptyValue = True
      GridControl3.RepositoryItems.Add(x)
  
  
      GridView3.Columns("cardNo").VisibleIndex = 1
      GridView3.Columns("cardNo").Width = 150
      GridView3.Columns("cardNo").ColumnEdit = x
  </code></pre>
  
  <p><a href="https://i.stack.imgur.com/SsptB.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/SsptB.png" alt="enter image description here"></a></p>