錯誤「800a005e」無效使用Null：「CDATE」使用ASP經典，VBScript中的函數

Question

我做了一個名爲FormatDT功能時，我把它放在\include\basic_function.asp

這裏是函數的代碼：

function FormatDT(ddate,format) 
     ddate = cdate(ddate) 
     Set re = New RegExp 
     re.Pattern = "%." 
     re.Global = True 
     re.IgnoreCase = False 
     're.MultiLine = True 
     set matches = re.execute(format) 
     hasil = "" 
     tmp = format 
     for each match in matches 
      fmt = match.value 
      select case fmt 
       case "%d" hasil = day(ddate) 
       case "%D" hasil = right("00" & day(ddate),2) 
       case "%m" hasil = month(ddate) 
       case "%M" hasil = right("00" & month(ddate),2) 
       case "%b" hasil = left(MonthName(month(ddate)),3) 
       case "%B" hasil = MonthName(month(ddate)) 
       case "%y" hasil = right(year(ddate),2) 
       case "%Y" hasil = year(ddate) 
       case "%h" hasil = hour(ddate) 
       case "%H" hasil = right("00" & hour(ddate),2) 
       case "%n" hasil = minute(ddate) 
       case "%N" hasil = right("00" & minute(ddate),2) 
       case "%s" hasil = second(ddate) 
       case "%S" hasil = right("00" & second(ddate),2) 
       case else hasil = replace(fmt,"%","") 
      end select 
      tmp = replace(tmp,fmt,hasil) 
     next 
     FormatDT = tmp 
    end function 

我在這裏使用此功能：

<input style="text-align:center" class="label" style="width:6em;" type="text" id="txtDate" name="txtDate" size="12" value="<%=FormatDt(dtglvalid,"%M/%D/%Y")%>" > 

，當網頁加載完畢後，我得到了這樣的錯誤消息：

Microsoft VBScript運行時錯誤 '800a005e' 無效使用Null： 'CDATE'
/include/basic_function.asp，線234

線234位於ddate = cdate(ddate)

如何解決這個錯誤？

Answer 1

ASP抱怨變量ddate爲NULL。看着你的代碼，它看起來像變量dtglvalid是NULL傳遞給函數並導致錯誤。你可以這樣做：

<input ... value="<% if not IsNull(dtglvalid) then Response.Write FormatDt(dtglvalid,"%M/%D/%Y") %>">