how to change color of content of combo box in vb.net

Question

_{Thursday, February 21, 2013 5:40 AM}

hi, guys,

i have a text box and a combo box, and what i want to do is when User selects the item from combo box it should be sent to the text box to display as string, and if that item is sent to the text box then the item's text or item's background color in the combo box should be changed. so that it can be notified that the item which has different color in combo box is Already selected.

and i also want that when selects the colored item from combo box, the item already selected should be deleted from the text box please help me how to do this in vb.net..

All replies (1)

_{Thursday, February 21, 2013 7:27 AM ✅Answered}

Create a variable to store the index of the currently selected item in the combobox.  Then use the example here

http://msdn.microsoft.com/en-us/library/system.windows.forms.combobox.drawmode(v=vs.100).aspx

which shows how to change the color, font and size of a combobox item based on its index.  You can use the same code, but adjust the color only based on the index number that indicates which item has been copied to the text box.

If the user selcts an item you first check if it's the selected item.  Adjust the saved variable and the text box accordingly, and continue to draw the combobox items.

Public Class Form1

    Private animals() As String
    Dim SelectedItemIndex As Integer = -1

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        ComboBox1.DrawMode = System.Windows.Forms.DrawMode.OwnerDrawFixed
        ComboBox1.DropDownWidth = 250
        ComboBox1.DropDownStyle = ComboBoxStyle.DropDown
        animals = New String() {"Elephant", "Crocodile", "lion"}
        ComboBox1.DataSource = animals
    End Sub

    Private Sub ComboBox1_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles ComboBox1.SelectedIndexChanged
        If SelectedItemIndex = ComboBox1.SelectedIndex Then
            SelectedItemIndex = -1
            tbxSelectedItem.Text = ""
        Else
            SelectedItemIndex = ComboBox1.SelectedIndex
            tbxSelectedItem.Text = ComboBox1.Items(SelectedItemIndex)
        End If
    End Sub

    Private Sub ComboBox1_DrawItem(ByVal sender As Object, ByVal e As System.Windows.Forms.DrawItemEventArgs) Handles ComboBox1.DrawItem
        Dim myFont As System.Drawing.Font = ComboBox1.Font
        Dim TextColor As New System.Drawing.Color
        If e.Index = selecteditemindex Then
            TextColor = System.Drawing.Color.Red
        Else
            TextColor = System.Drawing.Color.Black
        End If
        Dim myBrush As SolidBrush = New SolidBrush(TextColor)
        ' Draw the background of the item.
        e.DrawBackground()

        e.Graphics.DrawString(animals(e.Index), myFont, myBrush, New RectangleF(e.Bounds.X, e.Bounds.Y, e.Bounds.Width, e.Bounds.Height))

        ' Draw the focus rectangle if the mouse hovers over an item.
        e.DrawFocusRectangle()
    End Sub

End Class