从C＃.Net 2010开始推出VB6功能 [英] Pinvoke a VB6 function from C#.Net 2010

问题描述

我想从C＃PInvoke用VB6编写的函数。调用DLL的VB6代码声明如下：

I want to PInvoke a function written in VB6 from C#. The VB6 code that calls the DLL is declared like this:

Declare Function ApplyNNet Lib " location of the DLL file" (MyNNetType As String, MyAddress As String, MyInput() As Double) As Variant

My C＃版本如下所示： *

My C# version looks like this:*

[DllImport("NNetApply.dll")] 
public static extern object ApplyNNet(string type, string add, double[] data);

我这样称呼函数：

I call the function like this:

object P_ = ApplyNNet("Back Prop", address,data);

使用此声明我收到PInvoke错误：

With this declaration I receive a PInvoke error:

PInvoke restriction: cannot return variants.

推荐答案

首先，如果你有VB6代码调用这个.DLL，你为什么要调用C＃的VB6代码？绕过VB6代码直接进入.DLL！



其次，你不能调用返回Variant的VB6函数。 .NET中没有等效类型。您必须声明要返回的实际类型。

First, if you''ve got the VB6 code calling this .DLL, why are you calling the VB6 code from C#?? Just bypass the VB6 code and go straight to the .DLL!

Second, You can''t call a VB6 function that returns Variant. There is no equivilent type in .NET. You have to declare the actual type being returned.

这篇关于从C＃.Net 2010开始推出VB6功能的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！