Question

我想将一个xml文档从VBA模板传递给C ++ dll。我在这个dll中编写了函数：

extern "C" __declspec(dllexport) int __stdcall  ProcessRequest(IXMLDOMDocument* request, IXMLDOMDocument* response);

int __stdcall ProcessRequest(IXMLDOMDocument* request, IXMLDOMDocument* response)
{
    IXMLDOMElement* root = NULL;
    request->get_documentElement(&root);

    BSTR bstrVal = NULL;
    root->get_text(&bstrVal);

    ::MessageBox(NULL, bstrVal, L"lol", MB_OK);

    return 0;
}

我从VBA这样称呼它：

Public Declare Function ProcessRequest Lib "DllName" Alias "_ProcessRequest@8" (ByRef xml1 As DOMDocument, ByRef xml2 As DOMDocument) As Long

Public Sub ProcessRequestTest()
    Dim xml1 As New DOMDocument
    Dim xml2 As New DOMDocument
    Dim x As Long

    xml1.loadXML "<xml>lol</xml>"

    x = ProcessRequest(xml1, xml2)
End Sub

然而，我收到了违规错误：request-＆gt; get_documentElement（＆amp; root）; 那为什么会这样？这不是传递DOMDocument的正确方法吗？有没有办法，或者我应该只是传递字符串，来自巫婆dll会创建xml？

Answer 1

你已经在C ++中将该函数声明为ByVal，而在VB声明语句中声明了ByRef。

要传递接口ByRef，您需要将其声明为IXMLDOMDocument**

E.g。你需要在C ++中使用它：

extern "C" __declspec(dllexport) int __stdcall  ProcessRequest(IXMLDOMDocument** pprequest, IXMLDOMDocument** response);

int __stdcall ProcessRequest(IXMLDOMDocument** request, IXMLDOMDocument** ppresponse)

如何将DOMDocument从VBA传递到C ++ DLL

1 个答案: