日期选择下拉列表小控件

using  System; using  System.ComponentModel; using  System.Text; using  System.Web; using  System.Web.UI; using  System.Web.UI.WebControls;[assembly: TagPrefix( " EFPlatform.WebControls " ,  " efp " )] namespace  EFPlatform.WebControls{    [DefaultProperty( " Date " )]    [ToolboxData( " <{0}:DateDropDownList runat=server></{0}:DateDropDownList> " )]     public   class  DateDropDownList : WebControl, INamingContainer    {         #region  Properties          #region  Data(数据)          #region  Date         [Bindable( true )]        [Category( " Data " )]        [DefaultValue( " 1900-1-1 " )]         public  DateTime Date        {             get             {                 this .GetDate();                 return  (ViewState[ " Date " ]  ==   null )  ?  ( new  DateTime( 1900 ,  1 ,  1 )) : (DateTime)ViewState[ " Date " ];            }             set             {                ViewState[ " Date " ]  =  value;            }        }         #endregion          #region  FirstYear         [Category( " Data " )]        [DefaultValue( 1900 )]         public   int  FirstYear        {             get             {                 return  (ViewState[ " FirstYear " ]  ==   null )  ?   1900  : ( int )ViewState[ " FirstYear " ];            }             set             {                ViewState[ " FirstYear " ]  =  value;            }        }         #endregion          #region  LastYear         [Category( " Data " )]         public   int  LastYear        {             get             {                 return  (ViewState[ " LastYear " ]  ==   null )  ?  DateTime.Now.Year : ( int )ViewState[ " LastYear " ];            }             set             {                ViewState[ " LastYear " ]  =  value;            }        }         #endregion          #endregion          #region  Appearance(外观)          #region  SelectCssClass         [Category( " Appearance " )]         public   string  SelectCssClass        {             get             {                 return  (ViewState[ " SelectCssClass " ]  ==   null )  ?   string .Empty : ( string )ViewState[ " SelectCssClass " ];            }             set             {                ViewState[ " SelectCssClass " ]  =  value;            }        }         #endregion          #region  YearTitle         [Category( " Appearance " )]        [DefaultValue( " 年 " )]         public   string  YearTitle        {             get             {                 return  (ViewState[ " YearTitle " ]  ==   null )  ?   " 年 "  : ( string )ViewState[ " YearTitle " ];            }             set             {                ViewState[ " YearTitle " ]  =  value;            }        }         #endregion          #region  MonthTitle         [Category( " Appearance " )]        [DefaultValue( " 月 " )]         public   string  MonthTitle        {             get             {                 return  (ViewState[ " MonthTitle " ]  ==   null )  ?   " 月 "  : ( string )ViewState[ " MonthTitle " ];            }             set             {                ViewState[ " MonthTitle " ]  =  value;            }        }         #endregion          #region  DayTitle         [Category( " Appearance " )]        [DefaultValue( " 日 " )]         public   string  DayTitle        {             get             {                 return  (ViewState[ " DayTitle " ]  ==   null )  ?   " 日 "  : ( string )ViewState[ " DayTitle " ];            }             set             {                ViewState[ " DayTitle " ]  =  value;            }        }         #endregion          #endregion          #endregion          #region  GetDate          private   void  GetDate()        {             if (Page.IsPostBack)            {                 string  strYear  =  Page.Request.Form[ this .ClientID  +   " _Year " ];                 string  strMonth  =  Page.Request.Form[ this .ClientID  +   " _Month " ];                 string  strDay  =  Page.Request.Form[ this .ClientID  +   " _Day " ];                ViewState[ " Date " ]  =  DateTime.Parse( string .Format( " {0}-{1}-{2} " , strYear, strMonth, strDay));            }        }         #endregion          #region  BuildJScript          private   string  BuildJScript()        {            StringBuilder sb  =   new  StringBuilder();            sb.Append( " <script language="jscript"> <!-- " );            sb.Append( " function {0}_Day_Check() {{ " );            sb.Append( " var {0}_obj_Year = document.getElementById("{0}_Year"); " );            sb.Append( " var {0}_obj_Month = document.getElementById("{0}_Month"); " );            sb.Append( " if(parseInt({0}_obj_Month.value) == 2) {{ " );            sb.Append( " if(parseInt({0}_obj_Year.value) % 4 == 0) {{ " );            sb.Append( " {0}_Day_SetOptions(29); }} " );            sb.Append( " else {{ " );            sb.Append( " {0}_Day_SetOptions(28); }} }} " );            sb.Append( " else {{ " );            sb.Append( " switch(parseInt({0}_obj_Month.value)) {{ " );            sb.Append( " case 1: {0}_Day_SetOptions(31); break; " );            sb.Append( " case 3: {0}_Day_SetOptions(31); break; " );            sb.Append( " case 5: {0}_Day_SetOptions(31); break; " );            sb.Append( " case 7: {0}_Day_SetOptions(31); break; " );            sb.Append( " case 8: {0}_Day_SetOptions(31); break; " );            sb.Append( " case 10: {0}_Day_SetOptions(31); break; " );            sb.Append( " case 12: {0}_Day_SetOptions(31); break; " );            sb.Append( " case 4: {0}_Day_SetOptions(30); break; " );            sb.Append( " case 6: {0}_Day_SetOptions(30); break; " );            sb.Append( " case 9: {0}_Day_SetOptions(30); break; " );            sb.Append( " case 11: {0}_Day_SetOptions(30); break; " );            sb.Append( " default: break; }} }} }} " );            sb.Append( " " );            sb.Append( " function {0}_Day_SetOptions({0}_Day_Count) {{ " );            sb.Append( " var {0}_obj_Day = document.getElementById("{0}_Day"); " );            sb.Append( " var {0}_Day_SelectedDay; " );            sb.Append( " if({0}_obj_Day.value == "") {{ " );            sb.Append( " {0}_Day_SelectedDay = 1; }} " );            sb.Append( " else {{ " );            sb.Append( " {0}_Day_SelectedDay = parseInt({0}_obj_Day.value); }} " );            sb.Append( " if({0}_Day_SelectedDay > {0}_Day_Count) {{ " );            sb.Append( " {0}_Day_SelectedDay = {0}_Day_Count; }} " );            sb.Append( " {0}_obj_Day.length = 0; " );            sb.Append( " for(var i = 1; i <= {0}_Day_Count; i++) {{ " );            sb.Append( " {0}_obj_Day.options.add(new Option(i, i)); }} " );            sb.Append( " {0}_obj_Day.value = {0}_Day_SelectedDay; }} " );            sb.Append( " --> </script> " );             return   string .Format(sb.ToString(),  this .ClientID);        }         #endregion          #region  BuildHtmlElement          private   string  BuildHtmlElement()        {            StringBuilder sb  =   new  StringBuilder();            sb.AppendFormat( " <select id="{0}_Year" name="{0}_Year" οnchange="{0}_Day_Check();" class="{1}"> " ,  this .ClientID,  this .SelectCssClass);             for ( int  i  =   this .FirstYear; i  <=   this .LastYear; i ++ )            {                 if (i  ==   this .Date.Year)                {                    sb.AppendFormat( " <option value="{0}" selected>{0}</option> " , i);                }                 else                 {                    sb.AppendFormat( " <option value="{0}">{0}</option> " , i);                }            }            sb.AppendFormat( " </select> {1}<select id="{0}_Month" name="{0}_Month" οnchange="{0}_Day_Check();" class="{2}"> " ,  this .ClientID,  this .YearTitle,  this .SelectCssClass);             for ( int  i  =   1 ; i  <=   12 ; i ++ )            {                 if (i  ==   this .Date.Month)                {                    sb.AppendFormat( " <option value="{0}" selected>{0}</option> " , i);                }                 else                 {                    sb.AppendFormat( " <option value="{0}">{0}</option> " , i);                }            }            sb.AppendFormat( " </select>{1}<select id="{0}_Day" name="{0}_Day" οnmοuseοver="{0}_Day_Check();" class="{2}"> " ,  this .ClientID,  this .MonthTitle,  this .SelectCssClass);             for ( int  i  =   1 ; i  <=  DateTime.DaysInMonth( this .Date.Year,  this .Date.Month); i ++ )            {                 if (i  ==   this .Date.Day)                {                    sb.AppendFormat( " <option value="{0}" selected>{0}</option> " , i);                }                 else                 {                    sb.AppendFormat( " <option value="{0}">{0}</option> " , i);                }            }            sb.AppendFormat( " </select>{0} " ,  this .DayTitle);             return  sb.ToString();        }         #endregion          #region  override RenderChildren          protected   override   void  RenderChildren(HtmlTextWriter writer)        {            writer.Write( this .BuildJScript());            writer.Write( this .BuildHtmlElement());             base .RenderChildren(writer);        }         #endregion     }}