用VisualC#.NET编写服务器日期控件（源碼）

using  System;
using  System.Web.UI;
using  System.Web.UI.WebControls;
using  System.ComponentModel;
using  System.Drawing;

namespace  CreateTech.Retail.ServerControl
{
     public   enum  CalendarEnum
    {
        ShortDateTime,
        LongDateTime
    }

    [DefaultProperty( " Text " )]
    [ToolboxData( " <{0}:DatePicker runat=server></{0}:DatePicker> " )]
     public   class  DatePicker : WebControl, IPostBackEventHandler
    {
         // 选择日期按钮的默认样式
         private   const   string  _BUTTONDEFAULTSTYLE  =   " BORDER-RIGHT: gray 1px solid; BORDER-TOP: gray 1px solid; BORDER-LEFT: gray 1px solid; CURSOR: hand; BORDER-BOTTOM: gray 1px solid; " ;

         // 按钮默认文本
         private   const   string  _BUTTONDEFAULTTEXT  =   " ... " ;
         private  System.Web.UI.WebControls.Calendar _Calendar;

         public   override  ControlCollection Controls
        {
             get
            {
                EnsureChildControls();  // 确认子控件集都已被创建
                 return   base .Controls;
            }
        }

         // 创建子控件（服务器日历控件）
         protected   override   void  CreateChildControls()
        {
            Controls.Clear();
            _Calendar  =   new  Calendar();
            _Calendar.ID  =  MyCalendarID;
            _Calendar.SelectedDate  =  DateTime.Parse(Text);
            _Calendar.TitleFormat  =  TitleFormat.MonthYear;
            _Calendar.NextPrevFormat  =  NextPrevFormat.ShortMonth;
            _Calendar.CellSpacing  =   0 ;
            _Calendar.Font.Size  =  FontUnit.Parse( " 12px " );
            _Calendar.Font.Name  =   " Verdana " ;
            _Calendar.SelectedDayStyle.BackColor  =  ColorTranslator.FromHtml( " #333399 " );
            _Calendar.SelectedDayStyle.ForeColor  =  ColorTranslator.FromHtml( " White " );
            _Calendar.DayStyle.BackColor  =  ColorTranslator.FromHtml( " #CCCCCC " );
            _Calendar.TodayDayStyle.BackColor  =  ColorTranslator.FromHtml( " #999999 " );
            _Calendar.TodayDayStyle.ForeColor  =  ColorTranslator.FromHtml( " Aqua " );
            _Calendar.DayHeaderStyle.Font.Size  =  FontUnit.Parse( " 12px " );
            _Calendar.DayHeaderStyle.Font.Bold  =   true ;
            _Calendar.DayHeaderStyle.Height  =  Unit.Parse( " 12px " );
            _Calendar.DayHeaderStyle.ForeColor  =  ColorTranslator.FromHtml( " #333333 " );
            _Calendar.NextPrevStyle.Font.Size  =  FontUnit.Parse( " 12px " );
            _Calendar.NextPrevStyle.Font.Bold  =   true ;
            _Calendar.NextPrevStyle.ForeColor  =  ColorTranslator.FromHtml( " White " );
            _Calendar.TitleStyle.Font.Size  =  FontUnit.Parse( " 12px " );
            _Calendar.TitleStyle.Font.Bold  =   true ;
            _Calendar.TitleStyle.Height  =  Unit.Parse( " 12px " );
            _Calendar.TitleStyle.ForeColor  =  ColorTranslator.FromHtml( " White " );
            _Calendar.TitleStyle.BackColor  =  ColorTranslator.FromHtml( " #333399 " );
            _Calendar.OtherMonthDayStyle.ForeColor  =  ColorTranslator.FromHtml( " #999999 " );
            _Calendar.NextPrevFormat  =  NextPrevFormat.CustomText;
            _Calendar.NextMonthText  =   " 下月 " ;
            _Calendar.PrevMonthText  =   " 上月 " ;
            _Calendar.Style.Add( " display " ,  " none " );  // 默认不显示下拉日历控件
            _Calendar.SelectionChanged  +=   new  EventHandler(_Calendar_SelectionChanged);
             this .Controls.Add(_Calendar);
        }

        [
         Category( " Appearance " ),  // 该属性所属类别，参见图
         DefaultValue( "" ),  // 属性默认值
         Description( " 设置该日期控件的值。 " )  // 属性的描述
        ]
         public   string  Text
        {
             get
            {
                EnsureChildControls();
                 return  (ViewState[ " Text " ]  ==   null )  ?  System.DateTime.Today.ToString( " yyyy-MM-dd " ) : ViewState[ " Text " ].ToString();
            }
             set
            {
                EnsureChildControls();
                DateTime dt  =  System.DateTime.Today;
                 try
                {
                    dt  =  DateTime.Parse(value);
                }
                 catch
                {
                     throw   new  ArgumentOutOfRangeException( " 请输入日期型字符串（例如：1981-04-29）！ " );
                }

                ViewState[ " Text " ]  =  DateFormat  ==  CalendarEnum.LongDateTime  ?  dt.ToString( " yyyy-MM-dd " ) : dt.ToString( " yyyy-M-d " );
            }
        }

         // 重载服务器控件的Enabled属性，将选择日期按钮变灰（禁用）
         public   override   bool  Enabled
        {
             get
            {
                EnsureChildControls();
                 return  ViewState[ " Enabled " ]  ==   null   ?   true  : ( bool )ViewState[ " Enabled " ];
            }
             set
            {
                EnsureChildControls();
                ViewState[ " Enabled " ]  =  value;
            }
        }

         public   string  ButtonStyle
        {
             get
            {
                EnsureChildControls();
                 object  o  =  ViewState[ " ButtonSytle " ];
                 return  (o  ==   null )  ?  _BUTTONDEFAULTSTYLE : o.ToString();
            }
             set
            {
                EnsureChildControls();
                ViewState[ " ButtonSytle " ]  =  value;
            }
        }

        [
         DefaultValue(CalendarEnum.LongDateTime),
        ]
         public  CalendarEnum DateFormat
        {
             get
            {
                EnsureChildControls();
                 object  format  =  ViewState[ " DateFormat " ];
                 return  format  ==   null   ?  CalendarEnum.LongDateTime : (CalendarEnum)format;
            }
             set
            {
                EnsureChildControls();
                ViewState[ " DateFormat " ]  =  value;
                DateTime dt  =  DateTime.Parse(Text);
                Text  =  DateFormat  ==  CalendarEnum.LongDateTime  ?  dt.ToString( " yyyy-MM-dd " ) : dt.ToString( " yyyy-M-d " );
            }
        }

        [
         Browsable( false ),
         DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
        ]
         public   string  MyCalendarID  // 复合控件ID
        {
             get
            {
                EnsureChildControls();
                 return   this .ClientID  +   " _MyCalendar " ;
            }
        }

        [
         Browsable( false ),
         DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
        ]
         public   string  MyCalendarName  // 复合控件名称
        {
             get
            {
                EnsureChildControls();
                 return   this .UniqueID  +   " :MyCalendar " ;
            }
        }

        [
         Browsable( false ),
         DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
        ]
         public   string  DatePickerInputID  // 复合控件中输入框的ID
        {
             get
            {
                EnsureChildControls();
                 return   this .ClientID  +   " _DateInput " ;
            }
        }

        [
         Browsable( false ),
         DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
        ]
         public   string  DatePickerInputName  // 复合控件中输入框的名称
        {
             get
            {
                EnsureChildControls();
                 return   this .UniqueID  +   " :DateInput " ;
            }
        }

        [
         Browsable( false ),
         DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
        ]
         public   string  DatePickerButtonID  // 复合控件中按钮的ID
        {
             get
            {
                EnsureChildControls();
                 return   this .ClientID  +   " _DateButton " ;
            }
        }

        [
         Browsable( false ),
         DesignerSerializationVisibility(DesignerSerializationVisibility.Hidden)
        ]
         public   string  DatePickerButtonName  // 复合控件中按钮的名称
        {
             get
            {
                EnsureChildControls();
                 return   this .UniqueID  +   " :DateButton " ;
            }
        }

         public   string  ButtonText
        {
             get
            {
                EnsureChildControls();
                 return  ViewState[ " ButtonText " ]  ==   null   ?  _BUTTONDEFAULTTEXT : ( string )ViewState[ " ButtonText " ];
            }
             set
            {
                EnsureChildControls();
                ViewState[ " ButtonText " ]  =  value;
            }
        }

         ///
         ///  将此控件呈现给指定的输出参数。
         ///
         ///  要写出到的 HTML 编写器
         protected   override   void  Render(HtmlTextWriter output)
        {
             // 在页面中输出控件时，产生一个表格（二行二列），以下是表格的样式
            output.AddAttribute(HtmlTextWriterAttribute.Cellspacing,  " 0 " );
            output.AddAttribute(HtmlTextWriterAttribute.Border,  " 0 " );
            output.AddAttribute(HtmlTextWriterAttribute.Cellpadding,  " 0 " );

             // output.AddStyleAttribute("LEFT", this.Style["LEFT"]);
             // output.AddStyleAttribute("TOP", this.Style["TOP"]);
             // output.AddStyleAttribute("POSITION", "absolute");

             if  (Width  !=  Unit.Empty)
            {
                output.AddStyleAttribute(HtmlTextWriterStyle.Width, Width.ToString());
            }
             else
            {
                output.AddStyleAttribute(HtmlTextWriterStyle.Width,  " 200px " );
            }

            output.RenderBeginTag(HtmlTextWriterTag.Table);  // 输出表格
            output.RenderBeginTag(HtmlTextWriterTag.Tr);  // 表格第一行
            output.AddAttribute(HtmlTextWriterAttribute.Width,  " 90% " );
            output.RenderBeginTag(HtmlTextWriterTag.Td);

             // 以下是第一行第一列中文本框的属性及其样式设置

             if  ( ! Enabled)
            {
                output.AddAttribute(HtmlTextWriterAttribute.ReadOnly,  " true " );
            }

            output.AddAttribute(HtmlTextWriterAttribute.Type,  " Text " );
            output.AddAttribute(HtmlTextWriterAttribute.Id, DatePickerInputID);
            output.AddAttribute(HtmlTextWriterAttribute.Name, DatePickerInputName);
            output.AddAttribute(HtmlTextWriterAttribute.Value, Text);
            output.AddStyleAttribute(HtmlTextWriterStyle.Width,  " 100% " );
            output.AddStyleAttribute(HtmlTextWriterStyle.Height,  " 100% " );
            output.AddStyleAttribute(HtmlTextWriterStyle.FontFamily, Font.Name);
            output.AddStyleAttribute(HtmlTextWriterStyle.FontSize, Font.Size.ToString());
            output.AddStyleAttribute(HtmlTextWriterStyle.FontWeight, Font.Bold  ?   " bold "  :  "" );
            output.AddStyleAttribute(HtmlTextWriterStyle.BackgroundColor, ColorTranslator.ToHtml(BackColor));
            output.AddStyleAttribute(HtmlTextWriterStyle.Color, ColorTranslator.ToHtml(ForeColor));
            output.RenderBeginTag(HtmlTextWriterTag.Input);  // 输出文本框
            output.RenderEndTag();
            output.RenderEndTag();
            output.AddAttribute(HtmlTextWriterAttribute.Width,  " * " );
            output.RenderBeginTag(HtmlTextWriterTag.Td);

             // 以下是第一行第二列中按钮的属性及其样式设置

             if  ( ! Enabled)
            {
                output.AddAttribute(HtmlTextWriterAttribute.Disabled,  " true " );
            }

            output.AddAttribute(HtmlTextWriterAttribute.Type,  " Submit " );
            output.AddAttribute(HtmlTextWriterAttribute.Id, DatePickerButtonID);
            output.AddAttribute(HtmlTextWriterAttribute.Name, DatePickerButtonName);
            output.AddAttribute(HtmlTextWriterAttribute.Value, ButtonText);
            output.AddStyleAttribute(HtmlTextWriterStyle.Width,  " 100% " );
            output.AddAttribute(HtmlTextWriterAttribute.Onclick, Page.GetPostBackEventReference( this ));  // 点击按钮时需要回传服务器来触发后面的onClick事件

            output.AddAttribute(HtmlTextWriterAttribute.Style, ButtonStyle);
            output.RenderBeginTag(HtmlTextWriterTag.Input);  // 输出按钮
            output.RenderEndTag();
            output.RenderEndTag();

            output.RenderEndTag();
            output.RenderBeginTag(HtmlTextWriterTag.Tr);
            output.AddAttribute(HtmlTextWriterAttribute.Colspan,  " 2 " );
            output.RenderBeginTag(HtmlTextWriterTag.Td);
            _Calendar.RenderControl(output);  // 将日历子控件输出
            output.RenderEndTag();
            output.RenderEndTag();
            output.RenderEndTag();
        }

         // 复合控件必须继承IpostBackEventHandler接口，才能继承RaisePostBackEvent事件
         public   void  RaisePostBackEvent( string  eventArgument)
        {
            onClick(EventArgs.Empty);
        }

         protected   virtual   void  onClick(EventArgs e)
        {
             // 点击选择日期按钮时，如果日历子控件没有显示则显示出来并将文本框的值赋值给日历子控件
             if  (_Calendar.Attributes[ " display " ]  !=   "" )
            {
                _Calendar.SelectedDate  =  DateTime.Parse(Text);
                _Calendar.Style.Add( " display " ,  "" );
            }
        }

         // 复合控件中的日历控件日期变化事件

         private   void  _Calendar_SelectionChanged( object  sender, EventArgs e)
        {
             // 当选择的日期变化时，将所选日期赋值给文本框并将日历子控件隐藏
            Text  =  _Calendar.SelectedDate.ToString();
            _Calendar.Style.Add( " display " ,  " none " );
        }

         protected   override   void  RenderContents(HtmlTextWriter output)
        {
            output.Write(Text);
        }
    }
}