BUG: Setting Focus to a Masked Edit Control Causes Error

• Standard, Professional, and Enterprise Editions of Microsoft Visual Basic, 16-bit and 32-bit, for Windows, version 4.0

SYMPTOMS

Setting focus to a Masked Edit control, which previously did not have the focus, triggers the ValidationError event of the control. If the Masked Edit control loses the focus, the ValidationError event is fired again.

STATUS

Microsoft has confirmed this to be an issue in the Microsoft products listed at the beginning of this article. Microsoft is researching this issue and will post new information here in the Microsoft Knowledge Base as it becomes available.

WORKAROUND

The InValidText parameter received in the event represents the invalid characters that the user tried to type. When the event is fired erroneously because the control receives focus, the InValidText parameter is one character long, and becomes the same as the PromptChar. The example below avoids warning the user if a control is used to set focus to the control:

   Private Sub MaskEdBox1_ValidationError(InvalidText As String, _

   StartPosition As Integer)

   If InvalidText <> MaskEdBox1.PromptChar Then

        MsgBox "You are typing in the wrong stuff"

   End If

   End Sub

MORE INFORMATION

Steps to Reproduce Problem

1. Start a new project in Visual Basic. Form1 is created by default. Place a Masked Edit control and a Command button on to Form1.

2. Switch to the Properties window for the Masked Edit control, and change the Mask to #.

3. In the Click event for the Command button, place the following code:

      Private Sub Command1_Click()
   
      MaskEdBox1.SetFocus
   
      End Sub
   
   

4. In the ValidationError event for the Masked Edit control, enter the following code:

      Private Sub MaskEdBox1_ValidationError(InvalidText As String, _
   
      StartPosition As Integer)
   
          MsgBox "You are typing in the wrong stuff"
   
      End Sub
   
   

5. Run the project by pressing F5. Click on the Command button and the Msgbox indicates that the ValidationError event was incorrectly fired.

   Private Sub MaskEdBox1_ValidationError(InvalidText As String, _

   StartPosition As Integer)

   If InvalidText <> MaskEdBox1.PromptChar Then

        MsgBox "You are typing in the wrong stuff"

   End If

   End Sub