IsEmpty 检查类型 Variant 的变量是否包含特殊值 Empty .

IsEmpty checks whether a variable of type Variant contains a special value Empty.

您可能的意思是检查字符串是否为空字符串:

What you probably meant is checking if a string is an empty string:

If Len(cbo_moduleName.Value) = 0 Then
    ...
End If