检查VBA中的variant是否为null

Question

我将变量作为参数传递给函数

为简单起见,我已经提出了这个示例函数来解释我的情况

Public Function test()
Dim arr() As String
testing (arr)
End Function

Public Function testing(ar As Variant)
If ar = Empty Then
    MsgBox ("Hello")
End If
End Function

有时FilesDetails会出现这种情况null,在此期间函数返回" For loop not initialized"错误

如何检查变量是否为空？

我试过UBound(FilesDetails), FilesDetails.Count,IsNull(FilesDetails)但没有运气

Answer 1

我用下面的方法解决了这个问题

Public Function test()
Dim Arr(1) As String
Arr(0) = "d"
Dim x As Boolean
x = IsArrayAllocated(Arr)
End Function


Function IsArrayAllocated(Arr As Variant) As Boolean
        On Error Resume Next
        IsArrayAllocated = IsArray(Arr) And _
                           Not IsError(LBound(Arr, 1)) And _
                           LBound(Arr, 1) <= UBound(Arr, 1)
End Function

如果isArrayAllocated函数不为null,则返回true

Answer 2

试试这个 :-)

Dim var As Variant

If var = Empty Then
    MsgBox "Variant data is Empty"
End If

要么

If IsEmpty(var) Then
   MsgBox "Variant data is Empty"
End If