为什么“如果没有值”会抛出“需要对象（错误 424）”

Question

下面的代码Object Required (Error 424)在 if 语句中抛出与Nothing给定值无关的比较。为什么？

Public Function SqlizeCellValue(ByVal Value As Variant) As Variant
    If Value Is Nothing Then
        SqlizeCellValue = Nothing
    ElseIf Value = Null Then
        SqlizeCellValue = Null
    ElseIf Value = "" Then
        SqlizeCellValue = Null
    ElseIf Value = "0" Then
        SqlizeCellValue = Null
    ElseIf Value = "---" Then
        SqlizeCellValue = Null
    ElseIf LCase(Value) = "n.c." Then
        SqlizeCellValue = Null
    Else
        SqlizeCellValue = Value
    End If
End Function
Public Sub TestSqlizeCellValue()
    Debug.Assert SqlizeCellValue("") Is Null
    Debug.Assert SqlizeCellValue("0") Is Null
    Debug.Assert SqlizeCellValue("---") Is Null
    Debug.Assert SqlizeCellValue(Nothing) Is Nothing
    Debug.Assert SqlizeCellValue(Null) Is Null
End Sub

Answer 1

因为Value在你的函数定义中设置为 typeVariant并且只有 anObject可以Set是Nothing