Changing Colour of Listbox Items in VB.NET (.NET 2.0 Beta)

Its simple but finding the code for it on the Internet, and after getting the piece of code, cooking & making it work is bit difficult. So I thought let's put the steps on my blog to help others. This is windows application creating in Microsoft Visual Basic 2005 Express Edition Beta. Here in order to change the colour of items in our Listbox depending on our logic, we have to draw each item in the Listbox. That means, while rendering the Listbox items we have to select the brush, font, colors, etc and draw image inside the Listbox. The steps are:

1. For the "Listbox" change "DrwaMode" from 'Normal' to 'OwnerDrawFixed'.


2. Click on "Events" icon on "Properties" window, to create a method for "DrawItem" behaviour. Mine it is 'lstSitename_DrawItem ……… Handles lstSitename.DrawItem'. This method get invoke while rendering each item in the list box.


3. So while rendering each item, we have to check whether the item is selected or not. If selected then we have to highlight the item by changing the background colour. Otherwise we have to draw it in normal colors. Generally white background & black text for normal item and for selected item, light blue (CornflowerBlue) background & white text.


4. Now you want to render some items in the list box as per your logic. Suppose if an item is disabled you want to show that one with text strike off & highlight in brown colour.

You ask, 'I already binded/added the Listbox control somewhere else with DataSet or with some other source. How do I know now whether the item is disabled or not now!'
Yes, you don't have any database connection or DataSet to check the rendering item property in order to set text effect & color. But you have to have it. After binding/adding the list items to Listbox, you have to keep that datasource or DataSet in global variable or in persistent place. So that you can access the same in 'DrawItem' method. In this method while setting brush properties, you cross check current item property in datasource is enabled or disabled. According to that you set the text effects & colours. Please see the code below.

Global Variable

 Private SettingsDataSet As DataSet = Nothing

DrawItem Method

    Private Sub lstSitename_DrawItem
  (ByVal sender As Object, ByVal e As 
  System.Windows.Forms.DrawItemEventArgs) 
  Handles lstSitename.DrawItem
        e.DrawBackground()

        Dim myBrush As Brush
        Dim myBackColor As Color = Color.White
        Dim myForeColor As Color = Color.Black
        Dim myFont As Font = Me.Font

        If (e.State And DrawItemState.Selected) 
  = DrawItemState.Selected Then
            myBackColor = Color.CornflowerBlue
            myForeColor = Color.White
        End If

        'Checking the property of item in DataSet
        If isDisabled(lstSitename.Items(e.Index)) Then
            myFont = New Font(Me.Font, FontStyle.Strikeout)
            myForeColor = Color.Maroon
        End If

        myBrush = New SolidBrush(myBackColor)
        e.Graphics.FillRectangle(myBrush, e.Bounds)
        myBrush = New SolidBrush(myForeColor)
        e.Graphics.DrawString(lstSitename.Items(e.Index), 
  myFont, myBrush, New RectangleF(e.Bounds.X, 
  e.Bounds.Y, e.Bounds.Width, e.Bounds.Height))
        e.DrawFocusRectangle()

    End Sub

Property Checking

    Private Function isDisabled(ByVal s As String) 
  As Boolean
        Dim rtn As Boolean = False
        Dim rowData As DataRow
        Dim dvSettings As New DataView(
  SettingsDataSet.Tables("site"))
        Dim indx As Integer
        dvSettings.Sort = "name"
        If lstSitename.SelectedItems.Count > 0 Then
            indx = dvSettings.Find(s)
            rowData = dvSettings(indx).Row
            If rowData("disabled").ToString.Trim = "1" Then
                rtn = True
            End If
        End If
        dvSettings.Dispose()
        dvSettings = Nothing
        rowData = Nothing
        Return rtn
    End Function

If you need any help please post comment or mail me.