Option Explicit

Public Function Max(Optional ByVal Value) As Double
Dim x As Variant
Dim Temp As Double
Dim Temp1() As String

On Error Resume Next

If IsMissing(Value) = True Then
Exit Function

End If

If IsArray(Value) = True Then ''''''''(1)如果Value为数组'''''''
Temp = Value(LBound(Value))
For Each x In Value
If x > Temp Then
Temp = x

End If

Next

ElseIf VarType(Value) = vbString Then '''''(2)如果value为字符串''''''''
Temp1 = Split(Value, ",")
Temp = Temp1(LBound(Temp1))
For Each x In Temp1
If x > Temp Then
Temp = x

End If

Next

End If

Max = Temp

End Function

Private Sub Command1_Click()
Dim Value(4) As Double

Value(0) = -100.5
Value(1) = 9.56325
Value(2) = -20
Value(3) = 100.284
Value(4) = -30.5
Text2 = Max(Value)

End Sub

Private Sub Text1_Change()
Text2 = Max(Text1)

End Sub

Function Max(params() as integer) as integer

...
end function


--- 调用：
maxnumber=Max(Array(1,2,3,4,5,6))


不过这样的编程不是必要的，毕竟你写代码的时候用到多少参数就是多少参数，参数数量不应当随着运行状态而变化。但也不一定都是这样子，VS2005中就经常看到数组做为参数提供一套信息。