Hi Notre,

I have spent several hours researching on this problem, but unfortunately,
I haven't found a workaround to change the back color of the selected item
in a ComboBox control.

In my opinion, I suggest that you change the back color of a specified item
(or draw a colored border around the text of the item), which is a more
common usage.

To change the back color of a specified item or draw a colored border for
the specified item in a ComboBox control, set the DrawMode property of the
ComboBox to OwnerDrawFixed and then handle the DrawItem event or override
the OnDrawItem method.

The following is a sample of deriving a new control from ComboBox and
drawing colored borders around the specified items.

using System.Collections.Generic;
using System.Text;
using System.Windows.Forms;
using System.Drawing;

class MyComboBox:ComboBox
   {
       public MyComboBox()
       {
          this.DrawMode = DrawMode.OwnerDrawFixed;
       }

       private List<int> specialItems = new List<int>();
       public List<int> SpecialItems
       {
           get { return specialItems; }
       }

       protected override void OnDrawItem(DrawItemEventArgs e)
       {
          DrawItemEventArgs newe = null;
           Rectangle rect = new Rectangle();
           rect.X = e.Bounds.X;
           rect.Y = e.Bounds.Y;
           rect.Width = e.Bounds.Width - 1;
           rect.Height = e.Bounds.Height - 1;

           if (this.specialItems.Contains(e.Index))
           {
               newe = new DrawItemEventArgs(e.Graphics, e.Font, rect,
e.Index, e.State);
           }
           else
           {
               newe = e;
           }
           
           newe.DrawBackground();
           newe.Graphics.DrawString(this.Items[newe.Index].ToString(),
newe.Font, new SolidBrush(newe.ForeColor), newe.Bounds);
           if (this.specialItems.Contains(e.Index))
           {
               newe.Graphics.DrawRectangle(Pens.Blue, newe.Bounds);
           }          
           
           base.OnDrawItem(e);
       }
   }

Then in the DropDown event handler of the derived ComboBox control, add the
indexes of the specified items into the SpecialItems property of the
derived ComboBox.

Hope this helps.
If you have any concerns, please feel free to let me know.

Sincerely,
Linda Liu
Microsoft Online Community Support

==================================================
Get notification to my posts through email? Please refer to
http://msdn.microsoft.com/subscriptions/managednewsgroups/default.aspx#notif
ications.

Note: The MSDN Managed Newsgroup support offering is for non-urgent issues
where an initial response from the community or a Microsoft Support
Engineer within 1 business day is acceptable. Please note that each follow
up response may take approximately 2 business days as the support
professional working with you may need further investigation to reach the
most efficient resolution. The offering is not appropriate for situations
that require urgent, real-time or phone-based interactions or complex
project analysis and dump analysis issues. Issues of this nature are best
handled working with a dedicated Microsoft Support Engineer by contacting
Microsoft Customer Support Services (CSS) at
http://msdn.microsoft.com/subscriptions/support/default.aspx.
==================================================

This posting is provided "AS IS" with no warranties, and confers no rights.