DateTimePicker背景色修改(默认是白色)

codeproject上下载的,感谢那位国际友.

代码如下

//  *****************************************
//  ** Author: Vincenzo Rossi              **
//  ** Year  : 2008                        **
//  ** Mail  : [email protected]        **
//  **                                     **
//  ** Released under                      **
//  **   The Code Project Open License     **
//  *****************************************

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

namespace  DateTimePickerWithBackColor
{
     ///   <summary>
     ///      A derivation of DateTimePicker allowing to change background color
     ///   </summary>
     class  BCDateTimePicker : System.Windows.Forms.DateTimePicker
    {
         private  Color _backDisabledColor;

         public  BCDateTimePicker() :  base ()
        {
             this .SetStyle(ControlStyles.UserPaint,  true );
            _backDisabledColor  =  Color.FromKnownColor(KnownColor.Control);
        }

         ///   <summary>
         ///      Gets or sets the background color of the control
         ///   </summary>
        [Browsable( true )]
         public   override  Color BackColor
        {
             get  {  return   base .BackColor; }
             set  {  base .BackColor  =  value; }
        }

         ///   <summary>
         ///      Gets or sets the background color of the control when disabled
         ///   </summary>
        [Category( " Appearance " ), Description( " The background color of the component when disabled " )]
        [Browsable( true )]
         public  Color BackDisabledColor
        {
             get  {  return  _backDisabledColor; }
             set  { _backDisabledColor  =  value; }
        }


         protected   override   void  OnPaint(System.Windows.Forms.PaintEventArgs e)
        {
            Graphics g  =   this .CreateGraphics();
             // Graphics g = e.Graphics;
            
             // The dropDownRectangle defines position and size of dropdownbutton block, 
             // the width is fixed to 17 and height to 16. The dropdownbutton is aligned to right
            Rectangle dropDownRectangle  =   new  Rectangle(ClientRectangle.Width  -   17 ,  0 ,  17 ,  16 );
            Brush bkgBrush;
            ComboBoxState visualState;

             // When the control is enabled the brush is set to Backcolor, 
             // otherwise to color stored in _backDisabledColor
             if  ( this .Enabled) {
                 bkgBrush  =   new  SolidBrush( this .BackColor);
                 visualState  =  ComboBoxState.Normal;
            }
             else  {
                bkgBrush  =   new  SolidBrush( this ._backDisabledColor);
                visualState  =  ComboBoxState.Disabled;
            }

             //  Painting...in action

             // Filling the background
            g.FillRectangle(bkgBrush,  0 ,  0 , ClientRectangle.Width, ClientRectangle.Height);
            
             // Drawing the datetime text
            g.DrawString( this .Text,  this .Font, Brushes.Black,  0 ,  2 );

             // Drawing the dropdownbutton using ComboBoxRenderer
            ComboBoxRenderer.DrawDropDownButton(g, dropDownRectangle, visualState);

            g.Dispose();
            bkgBrush.Dispose();
        }
    }
}