[Only3]

without api

Code

Class WMTextBox
    Inherits TextBox

    Private WaterMark As String = "Water Mark"
    Sub New()
      ForeColor = Color.LightGray
      Text = WaterMark
      AddHandler Me.Leave, AddressOf Me_Leave
      AddHandler Me.Enter, AddressOf Me_Enter
    End Sub

    Private Sub Me_Leave(sender As Object, e As EventArgs)
      If Text.Length = 0 Then
      Text = WaterMark
      ForeColor = Color.LightGray
      End If
    End Sub
    Private Sub Me_Enter(sender As Object, e As EventArgs)
      If Text = WaterMark Then
      Text = ""
      ForeColor = Color.Black
      End If
    End Sub
End Class

[Only3]

And what if I write the Watermark string itself in the textbox ? This code is buggy, sorry...

🤦‍♂ change it to Public

Code

Class WMTextBox
    Inherits TextBox

    Public WaterMark As String = "Water Mark"
    Sub New()
      ForeColor = Color.LightGray
      Text = WaterMark
      AddHandler Me.Leave, AddressOf Me_Leave
      AddHandler Me.Enter, AddressOf Me_Enter
    End Sub

    Private Sub Me_Leave(sender As Object, e As EventArgs)
      If Text.Length = 0 Then
      Text = WaterMark
      ForeColor = Color.LightGray
      End If
    End Sub
    Private Sub Me_Enter(sender As Object, e As EventArgs)
      If Text = WaterMark Then
      Text = ""
      ForeColor = Color.Black
      End If
    End Sub
End Class