Use dropdownlist in. Net to select a date (vb code)

After reading the C # written by others, I switched it and then changed it to this

 

In addition, there is a code that I wrote to check whether the verification date is legal. It will be followed by VB C # It will only show that it will not be written.

 

 'Determine the leap year ================================< br/> private function checkleap (byval year as integer) as Boolean <br/> If (Year mod 4 = 0) andalso (Year mod 100 <> 0) orelse (Year mod 400 = 0) then <br/> return true <br/> else <br/> return false <br/> end if <br/> end function <br/> 'indicates the end of a leap year = ====================================</P> <p> 'Day of month for binding ========== ================< br/> private sub binddays (byval year as integer, byval month as integer) <br/> dim I as integer <br/> dim Alday as new arraylist () </P> <p> select case month <br/> case 1, 3, 5, 7, 8, 10, 12 <br/> for I = 1 to 31 <br/> Alday. add (I) <br/> next <br/> 'exit select <br/> case 2 <br/> If checkleap (year) then <br/> for I = 1 to 29 <br/> Alday. add (I) <br/> next <br/> else <br/> for I = 1 to 28 <br/> Alday. add (I) <br/> next <br/> end if <br/> 'exit select <br/> case 4, 6, 9, 11 <br/> for I = 1 to 30 <br/> Alday. add (I) <br/> next <br/> 'exit select <br/> end select <br/> dropdownlist_day.datasource = Alday <br/> dropdownlist_day.databind () <br/> end sub <br/> 'end of the number of days of the month for binding ===========================</P> <p> 'drag three dropdownlist dropdownlist_year dropdownlist_month dropdownlist_day to autopostback </P> <p> protected sub page_load (byval sender as object, byval e as system. eventargs) handles me. load </P> <p> dim alyear as new arraylist () <br/> dim I as integer <br/> for I = 1940 to 1992 <br/> alyear. add (I) <br/> next <br/> dim almonth as new arraylist <br/> for I = 1 to 12 <br/> almonth. add (I) <br/> next <br/> if not me. ispostback then <br/> dropdownlist_year.datasource = alyear <br/> dropdownlist_year.databind () <br/> dropdownlist_year.selectedvalue = 1985 <br/> 'binding year <br/> dropdownlist_month.datasource = almonth <br/> dropdownlist_month.databind () <br/> dropdownlist_month.selectedvalue = 6 <br/> 'monthly binding <br/> dim year as integer, month as integer <br/> year = int32.parse (dropdownlist_year.selectedvalue) <br/> month = int32.parse (dropdownlist_month.selectedvalue) <br/> binddays (year, month) <br/> 'binding day <br/> dropdownlist_day.selectedvalue = 15 <br/> end if <br/> end sub </P> <p> protected sub dropdownlist_year_selectedindexchanged (byval sender object, byval e as system. eventargs) handles dropdownlist_year.selectedindexchanged <br/> dim year as integer, month as integer <br/> year = int32.parse (cost) <br/> month = int32.parse (dropdownlist_month.selectedvalue) <br/> binddays (year, month) <br/> end sub </P> <p> protected sub dropdownlist_month_selectedindexchanged (byval sender as object, byval e as system. eventargs) handles dropdownlist_month.selectedindexchanged <br/> dim year as integer, month as integer <br/> year = int32.parse (cost) <br/> month = int32.parse (dropdownlist_month.selectedvalue) <br/> binddays (year, month) <br/> end sub

 

'Date of verification is valid ===================================================< br/>' the 1992 1940 in the table is the year range set by me. <br/> the label_false error message is displayed on the 'page. <br/>' The checkleap function of the leap is used in the above Code. <br/> If (yy> 1992 or (yy <1940 )) or (mm <1) or (MM> 12) Then <br/> label_false.text = "date of birth is incorrect. Please try again! "<Br/> return <br/> end if <br/> select case mm <br/> case 1, 3, 5, 7, 8, 10, 12 <br/> If DD> 31 or DD <1 then <br/> label_false.text = "the birth date is incorrect. Please try again! "<Br/> return <br/> end if <br/> case 4, 6, 9, 11 <br/> If DD> 30 or DD <1 then <br/> label_false.text = "the birth date is incorrect. Please try again! "<Br/> return <br/> end if <br/> case 2 <br/> If checkleap (yy) = false then <br/> If DD> 28 or DD <1 then <br/> label_false.text = "the birth date is incorrect. Please try again! "<Br/> return <br/> end if <br/> else <br/> If DD> 29 or DD <1 then <br/> label_false.text =" Birth date Error, please try again! "<Br/> return <br/> end if <br/> end select <br/> 'after verification, the data is converted to a normal date type dateout <br/> dim yymmdd as string = YY & "-" & mm & "-" & DD <br/> dim dateout as date = datetime. parse (yymmdd)