Error: WTclient - Failed to Execute OPCENUM

Question

我正在编写一个 OPC 客户端来获取标签并将标签发送到 OPC 服务器，但我遇到了这个错误： WTclient - 无法执行 OPCENUM 我的代码非常简单，我正在按照我在 Internet 上找到的完美运行的示例应用程序进行操作。我的程序可以完美编译并运行，但是当到达 Numbr = NumberOfOPCServers(TRUE, MachineName);弹出错误的行。

我的 .ccp 是：

#include "stdafx.h"
#include "opcda.h"
#include "opc_ae.h"
#include "wtclientapi.h"
#include "OPC2.h"

int _tmain(int argc, _TCHAR* argv[])
{
    int Numbr;
    MachineName = "";
    Numbr = NumberOfOPCServers(TRUE, MachineName);
    return 0;
}

深入调试另一个互联网例子，我发现错误来自这个函数：

int CWTclientApp::GetServerListFromOPCENUM(CString pathname)
{
    IOPCServerList *gpOPC;
    HRESULT hr, hr2;
    IEnumGUID *pEnumGUID;
    CLSID catid, clsid;
    unsigned long c;
    LPOLESTR pszProgID, pszUserType;
    int i;
    OPCSVRDESCR *pSvr;

    for (i=0; i<MyServerList.GetSize(); i++)
        {
        pSvr = (OPCSVRDESCR *)MyServerList.GetAt(i);
        delete (pSvr);
        }
    MyServerList.RemoveAll();

    // create the enumerator object
    gpOPC = CreateServerEnumerator(pathname);
    if (gpOPC == NULL)
        {
        DoErrorMsg ( 0, "Failed to Execute OPCENUM");
        // revert to search of Registry if OPCENUM fails to execute
        return (GetServerListFromRegistry());
        }
............................................

从函数 NumberOfOPCServers():

中调用

_declspec(dllexport) int  WINAPI NumberOfOPCServers (bool UseOPCENUM, LPCSTR MachineName)
{
    CWTclientApp    *pApp;
    CString path;

    path = MachineName;
    path.MakeUpper();
    if (path == "LOCAL")
        path = "";
    else
        path = MachineName;
    pApp = (CWTclientApp *)AfxGetApp();
    if (UseOPCENUM)
        return (pApp->GetServerListFromOPCENUM(path));
    else 
        return (pApp->GetServerListFromRegistry());
}

知道为什么会出现此错误吗？看起来 OPCenum.exe 没有在我的机器（本地服务器）上枚举我的 OPC 服务器运行，但为什么呢？（下载的应用程序有，我的没有）

谢谢!!!!

编辑---------------------------------------- ---------------------------- CreateServerEnumerator():

IOPCServerList *CWTclientApp::CreateServerEnumerator (CString   PathName)
{
    HRESULT r2;
    MULTI_QI mqi;
    COSERVERINFO    sin, *sinptr;
    DWORD clsctx;

    // set up server info
    //
    if (PathName.GetLength() > 0)
        {
        sinptr = &sin;
        sin.dwReserved1 = 0;
        sin.dwReserved2 = 0;
        sin.pwszName = WSTRFromCString (PathName, FALSE);
        sin.pAuthInfo = 0;
        clsctx = CLSCTX_REMOTE_SERVER;
        } 
    else
        {
        sinptr = 0;     // pointer should be NULL if local
        clsctx = CLSCTX_LOCAL_SERVER;
        }

    // set up mqi
    //
    mqi.pIID = &IID_IOPCServerList;
    mqi.hr = 0;
    mqi.pItf = 0;    

    r2 = CoCreateInstanceEx(CLSID_OPCServerList, NULL, 
        clsctx, sinptr, 1, &mqi);    
    if (PathName.GetLength() > 0)
        WSTRFree (sin.pwszName, FALSE);    
    if (FAILED(r2) || FAILED(mqi.hr))
        return (NULL);    
    return (IOPCServerList*)mqi.pItf;
}

Answer 1

在调用任何其他 COM 函数之前，只需在使用 COM (OPC Classic) 的每个线程中调用 CoInitialize (https://msdn.microsoft.com/en-us/library/windows/desktop/ms678543(v=vs.85).aspx) or CoInitializeEx (https://msdn.microsoft.com/en-us/library/windows/desktop/ms695279(v=vs.85).aspx)。

CoInitialize 已过时，因此您应该使用 CoInitializeEx。

Microsoft 在他们的文档中对此函数说："CoInitializeEx must be called at least once, and is usually called only once, for each thread that uses the COM library".

Error: WTclient - Failed to Execute OPCENUM

Error: WTclient - Failed to Execute OPCENUM

c++

opc