GhostText with VB.Net

Question

Hi guys, I tried to create ghost text using shortcuts above text boxes. I am using VB.Net2005. I accomplished this with this code:

Public Class frmDataEntry

    Private Sub PhantomTextLastName()
        If txtLastName.Text = "" Then
            lblLastName.Visible = True
        Else
            lblLastName.Visible = False
        End If
    End Sub

    Private Sub PhantomTextFirstName()
        If txtFirstName.Text = "" Then
            lblFirstName.Visible = True
        Else
            lblFirstName.Visible = False
        End If
    End Sub

    Private Sub PhantomTextMiddleInitial()
        If txtMiddleInitial.Text = "" Then
            lblMiddleInitial.Visible = True
        Else
            lblMiddleInitial.Visible = False
        End If
    End Sub

    Private Sub txtLastName_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtLastName.Click
        lblLastName.Text = "Last Name"
    End Sub

    Private Sub txtLastName_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles txtLastName.KeyDown
        PhantomTextLastName()
    End Sub

    Private Sub txtLastName_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtLastName.TextChanged
        PhantomTextLastName()
    End Sub

    Private Sub lblLastName_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lblLastName.Click
        txtLastName.Focus()
    End Sub

    Private Sub txtFirstName_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtFirstName.Click
        lblFirstName.Text = "First Name"
    End Sub

    Private Sub txtFirstName_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles txtFirstName.KeyDown
        PhantomTextFirstName()
    End Sub

    Private Sub txtFirstName_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtFirstName.TextChanged
        PhantomTextFirstName()
    End Sub

    Private Sub lblFirstName_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lblFirstName.Click
        txtFirstName.Focus()
    End Sub

    Private Sub lblMiddleInitial_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles lblMiddleInitial.Click
        txtMiddleInitial.Focus()
    End Sub

    Private Sub txtMiddleInitial_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles txtMiddleInitial.Click
        lblMiddleInitial.Text = "Middle I."
    End Sub

    Private Sub txtMiddleInitial_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles txtMiddleInitial.KeyDown
        PhantomTextMiddleInitial()
    End Sub

    Private Sub txtMiddleInitial_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtMiddleInitial.TextChanged
        PhantomTextMiddleInitial()
    End Sub
End Class

Is there a way to reduce this code, so when I try to add other text fields, I no longer have to retype a bunch of codes. I have basic knowledge using a module and class, but I really don't know how to apply this with this project. I am a newbie and if you have a tutorial that could help me solve this problem, kindly give me a link d. Thanks in advance, and God bless.

Answer 1

usercontrol. :

 Public Class GhostTextbox

    Private _ghostText As String
    Public Property GhostText As String
        Get
            Return _ghostText
        End Get
        Set(ByVal Value As String)
            _ghostText = Value
        End Set
    End Property

    Public Property ActualText As String
        Get
            Return Me.TextBox1.Text
        End Get
        Set(ByVal Value As String)
            Me.TextBox1.Text = Value
        End Set
    End Property

    Private Sub PhantomText()
        If TextBox1.Text = "" Then
            Label1.Visible = True
        Else
            Label1.Visible = False
        End If
    End Sub

    Private Sub TextBox1_Click(sender As Object, e As System.EventArgs) Handles TextBox1.Click
        Label1.Text = GhostText
    End Sub

    Private Sub TextBox1_KeyDown(sender As Object, e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyDown
        PhantomText()
    End Sub

    Private Sub TextBox1_TextChanged(sender As System.Object, e As System.EventArgs) Handles TextBox1.TextChanged
        PhantomText()
    End Sub

    Private Sub GhostTextbox_Load(sender As Object, e As System.EventArgs) Handles Me.Load
        Label1.Text = GhostText
    End Sub
End Class

, TextBox. , , GhostText , , .

Answer 2

1 Sub, ,

:

Private Sub txtMiddleInitial_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtMiddleInitial.TextChanged
    PhantomTextMiddleInitial()
End Sub

Private Sub txtFirstName_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtFirstName.TextChanged
    PhantomTextFirstName()
End Sub

Private Sub txtLastName_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtLastName.TextChanged
    PhantomTextLastName()
End Sub

To:

Private Sub txtControl_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles txtLastName.TextChanged, txtFirstName.TextChanged, txtMiddleInitial.TextChanged
    PhantomTextLastName()
End Sub

..

MSDN: Windows

Answer 3

NativeWindow :

Public Class WaterMark
  Inherits NativeWindow

  <DllImport("User32.dll")> _
  Public Shared Function GetWindowDC(ByVal hWnd As IntPtr) As IntPtr
  End Function

  <DllImport("user32.dll")> _
  Private Shared Function ReleaseDC(ByVal hWnd As IntPtr, ByVal hDC As IntPtr) As Boolean
  End Function

  Private _TextBox As TextBox
  Private _EmptyMessage As String

  Private Const WM_PAINT As Integer = &HF

  Public Sub New(ByVal textBox As TextBox, ByVal emptyMessage As String)
    _TextBox = TextBox
    AddHandler _TextBox.TextChanged, AddressOf OnTextChanged
    _EmptyMessage = emptyMessage
    MyBase.AssignHandle(textBox.Handle)
  End Sub

  Private Sub OnTextChanged(ByVal sender As Object, ByVal e As EventArgs)
    If _TextBox.Text = String.Empty Then
      _TextBox.Invalidate()
    End If
  End Sub

  Public Overrides Sub ReleaseHandle()
    RemoveHandler _TextBox.TextChanged, AddressOf OnTextChanged
    MyBase.ReleaseHandle()
  End Sub

  Protected Overrides Sub WndProc(ByRef m As Message)
    MyBase.WndProc(m)
    If m.Msg = WM_PAINT AndAlso _TextBox.Text = String.Empty Then
      Dim dc As IntPtr = GetWindowDC(m.HWnd)
      Using g As Graphics = Graphics.FromHdc(dc)
        TextRenderer.DrawText(g, _EmptyMessage, _TextBox.Font, _TextBox.ClientRectangle, Color.Gray, Color.Empty, TextFormatFlags.Left Or TextFormatFlags.VerticalCenter)
      End Using
      ReleaseDC(m.HWnd, dc)
    End If
  End Sub
End Class

TextBox :

Private _WaterMark As WaterMark

Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
  _WaterMark = New WaterMark(TextBox1, "Enter Something:")
End Sub