检测参数是否的为空的Function

因为所输入的参数类型不同，所以判断的方法也不一样。如何正确的判断参数是否为空？

具体的请看下文所示：

<%

'Check a variable isn't "empty"

Function IsBlank(ByRef TempVar)

'by default, assume it's not blank

IsBlank = False

'now check by variable type

Select Case VarType(TempVar)

'Empty & Null

Case 0, 1

IsBlank = True

'String

Case 8

If Len(TempVar) = 0 Then

IsBlank = True

End If

'Object

Case 9

tmpType = TypeName(TempVar)

If (tmpType = "Nothing") Or (tmpType = "Empty") Then

IsBlank = True

End If

'Array

Case 8192, 8204, 8209

'does it have at least one element?

If UBound(TempVar) = -1 Then

IsBlank = True

End If

End Select

End Function

%>

Example Usage

<%

If IsBlank(Session("username"))Then

response.redirect("LoginFail.htm")

End If

%>