vb2012 调用refprop.dll 的疑问

Question

我用你在另一个回答里贴的代码
<DllImport("refprop.dll", CharSet:=CharSet.Auto)> _
Private Shared Sub SETUPdll( _
ByRef i As Long, _
ByVal hfld As String, _
ByVal hfmix As String, _
ByVal hrf As String, _
ByRef ierr As Long, _
ByVal herr As String, _
ByRef ln1 As Long, _
ByRef ln2 As Long, _
ByRef ln3 As Long, _
ByRef ln4 As Long)
End Sub
复制到程序里之后，得到“未定义类型“DllImport”的错误

请问怎么回事？
望能解答！

Answer 1

Excel一样：=Density("argon","TP","SI",300,10)追问

得先调用，才能查物性吧