[ToolboxBitmap(typeof(ComboBox))]
class ComboBoxEx : ComboBox
{
public ComboBoxEx()
{
this.DrawMode = DrawMode.OwnerDrawFixed;
this.DrawItem += ComboBoxEx_DrawItem;
this.DropDownBorderColor = Color.Red;
this.DropDownBackColor = Color.Yellow;
}
[Category("Appearance")]
[Description("The border color of the drop down list")]
[DefaultValue(typeof(Color), "Red")]
public Color DropDownBorderColor { get; set; }
[Category("Appearance")]
[Description("The background color of the drop down list")]
[DefaultValue(typeof(Color), "Yellow")]
public Color DropDownBackColor { get; set; }
void ComboBoxEx_DrawItem(object sender, DrawItemEventArgs e)
{
if (e.Index < )
return;
if ((e.State & DrawItemState.ComboBoxEdit) == DrawItemState.ComboBoxEdit)
return
// Draw the background of the item.
if (
((e.State & DrawItemState.Focus) == DrawItemState.Focus) ||
((e.State & DrawItemState.Selected) == DrawItemState.Selected) ||
((e.State & DrawItemState.HotLight) == DrawItemState.HotLight)
)
{
e.DrawBackground();
}
else
{
Brush backgroundBrush = new SolidBrush(DropDownBackColor);
e.Graphics.FillRectangle(backgroundBrush, e.Bounds);
}
//Draw item text
e.Graphics.DrawString(Items[e.Index].ToString(), this.Font, Brushes.Black,
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.
if ((e.State & DrawItemState.Focus) == DrawItemState.Focus)
e.DrawFocusRectangle();
//Draw the border around the whole DropDown area
Pen borderPen = new Pen(DropDownBorderColor, );
Point start;
Point end;
if (e.Index == )
{
//Draw top border
start = new Point(e.Bounds.Left, e.Bounds.Top);
end = new Point(e.Bounds.Left + e.Bounds.Width - , e.Bounds.Top);
e.Graphics.DrawLine(borderPen, start, end);
}
//Draw left border
start = new Point(e.Bounds.Left, e.Bounds.Top);
end = new Point(e.Bounds.Left, e.Bounds.Top + e.Bounds.Height - );
e.Graphics.DrawLine(borderPen, start, end);
//Draw Right border
start = new Point(e.Bounds.Left + e.Bounds.Width - , e.Bounds.Top);
end = new Point(e.Bounds.Left + e.Bounds.Width - , e.Bounds.Top + e.Bounds.Height - );
e.Graphics.DrawLine(borderPen, start, end);
if (e.Index == Items.Count - )
{
//Draw bottom border
start = new Point(e.Bounds.Left, e.Bounds.Top + e.Bounds.Height - );
end = new Point(e.Bounds.Left + e.Bounds.Width - , e.Bounds.Top + e.Bounds.Height - );
e.Graphics.DrawLine(borderPen, start, end);
}
}
}