从非托管C多次调用C＃COM对象 [英] Multiple calls to a C# COM object from unmanaged C

问题描述

所以我看了一下来电从非托管C ++代码管理.NET C＃COM对象 [ ]并且能够创建我的表单并毫无问题地调用它。现在我想多次调用表单，允许用户每次都提供输入。 C或C ++它并不重要，它的混合对我的解决方案来说很好。



有什么我想念的吗？我不能简单地将下面的行放入for循环吗？：

So I took a look at the article Calling Managed .NET C# COM Objects from Unmanaged C++ Code[] and was able to create my form and call it without issue. Now I would like to call the form multiple times allowing user to provide input each time. C or C++ it doesn't really matter and a mix of it is fine for my solution.

Is there something I'm missing? Shouldn't I be able to simply place the line below into a for loop?:

pDotNetCOMPtr->ShowCOMDialog ();

第一次迭代后，表单永远不会出现。我可能误解了事物的顺序，但我觉得我不应该再次调用CoInitialize或CreateInstance（）。下面是我正在使用的简单代码示例。

The form never appears after the first iteration. It's possible I'm misunderstanding the order of things, but I don't feel I should have to call CoInitialize or CreateInstance() again. Below is the simple code sample I'm using.

int _tmain(int argc, _TCHAR* argv[])
{
    //for(int i = 0; i < 4;i++)
    {
        CoInitializeEx(NULL, COINIT_MULTITHREADED);

        int theResult = -1;
        long result = 0;
        COMTesting::IProgramPtr pDotNetCOMPtr;
        HRESULT hRes = pDotNetCOMPtr.CreateInstance(COMTesting::CLSID_Program);

        for(int i = 0; i < 4;i++)
        {  

            if (hRes == S_OK)
            {
                BSTR MyBstr = SysAllocString(L"Proof I can Pass a String!");
                BSTR myReturnStr;
                result = pDotNetCOMPtr->LaunchDialog(MyBstr, &myReturnStr);
                printf("The Result was %i\r\n", result);
                char *p = _com_util::ConvertBSTRToString(myReturnStr);
                printf(p);
                printf("\r\n"); 
                printf("Press Any Key to Continue\r\n");
                getchar();
                delete [] p;
            }
        }

        CoUninitialize ();
    }
    return 0;
}

非常感谢能够提供帮助的任何人，或者如果我是正确的方向，请指出我误解COM调用是如何工作的。



编辑：我意识到我的COM调用的返回实际上导致了HRESULT。如果这在第一次返回S_OK时有帮助。进一步的迭代返回看似未初始化的值，例如-2146233079

Thank you so much for anyone that could provide assistance, or point me in the right direction if I'm misunderstanding how the COM calls are working.

I realize that the return of my COM call actually results in a HRESULT. If this helps at all the first time it returns S_OK. Further iterations return what appear to be uninitialized values such as -2146233079

推荐答案

更好地向您引用的文章的作者提出问题。加载文章页面，在最后找到评论和讨论，然后单击添加评论或问题。作者将收到通知并有机会回答您。



对我而言，本文的全部主题及其目的尚不清楚。当您通过某些非托管代码使用COM对象时，无论如何实现此COM对象，在.NET，C＃或任何其他方式中，它都应该正确实现。消耗COM对象的技术总是相同的，取决于您的用户代码及其语言。

-SA

Better ask your questions to the author of the article you referenced. Load the article page, locate "Comments and Discussions" at the end and click "Add a Comment or Question". The author will get a notification and a chance to answer you.

To me, the whole subject of this article and its purpose is not clear. When you consume a COM object by some unmanaged code, it does not matter how this COM object is implemented, in .NET, C#, or any other way, it only should be implemented correctly. The technique of consumption of COM object is always the same and depends on your user code and its language.

—SA

这篇关于从非托管C多次调用C＃COM对象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！