Changing the background color of a DateTimePicker in .NET

Question

In .NET (at least in the 2008 version, and maybe in 2005 as well), changing the BackColor property of a DateTimePicker has absolutely no affect on the appearance. How do I change the background color of the text area, not of the drop-down calendar?

Edit: I was talking about Windows forms, not ASP.

Answer 1

According to MSDN :

Setting the BackColor has no effect on the appearance of the DateTimePicker.

You need to write a custom control that extends DateTimePicker. Override the BackColor property and the WndProc method.

Whenever you change the BackColor, don't forget to call the myDTPicker.Invalidate() method. This will force the control to redrawn using the new color specified.

const int WM_ERASEBKGND = 0x14;
protected override void WndProc(ref System.Windows.Forms.Message m)
{
    if(m.Msg == WM_ERASEBKGND)
    {
        using(var g = Graphics.FromHdc(m.WParam))
        {
            using(var b = new SolidBrush(_backColor))
            {
                g.FillRectangle(b, ClientRectangle);
            }
        }
        return;
    }

    base.WndProc(ref m);
}