我需要访问ROT对象的帮助. -非常接近，现在只是链接器错误-帮助！ [英] I need help accessing ROT object please. - So close, now just a linker error -Help!

问题描述

一小段代码，注释讲述了这个故事.
遇到任何帮助，我们将不胜感激.

Hi,

Small bit of code, Comments tell the story.
Any help would be appreciated as I''m stuck.

void Cbcr_18_PCEQ_SS_control::SlaveCheckin(GUID SlaveGUID)
{
     IUnknown *pUnk;
     void** ppv;

HRESULT hr = GetActiveObject(SlaveGUID, NULL, (IUnknown**)&pUnk); // SlaveGUID is correct,
                                                                  // hr = 0;
hr = pUnk->QueryInterface( IID_IUnknown, (void**)&ppv );          // hr = 0, ppv gets
                                                                  // assigned value
 ppv ->  // IDE does not populate with choices as if it's invalid,
         // or I don't understand what I'm doing.
         // What to do here? The object has a static function I need to call.

推荐答案

好吧，它是一个void**，当然它不会填充. IDE不会解释返回值.如果要让IDE填充一个指针，则必须告诉它它是哪种类型的指针.

例如，如果您具有:

Well, its a void**, of course its not going to get populated. IDEs will not interpret return values. If you want the IDE to populate a pointer, you have to tell it what type of pointer it is.

For example, if you have:

void *myClass;

...然后您实际上得到了一个有效的指针:

...and later on you actually get a valid pointer:

((CValidClass *)myClass)->Method();

或...

or...

CValidClass *ptrClass = (CValidClass *) myClass;
ptrClass->Method();

您已请求一个IUnknown接口(确定要执行的操作?)，以便可以安全地将ppv强制转换为(IUnknown *)并调用可用的接口方法(QueryInterface, AddRef, Release).

You have requested a IUnknown interface (are you sure is what you intended to do?) so you may safely cast ppv to (IUnknown *) and call the available interface methods (QueryInterface, AddRef, Release).

在Albert的帮助下，我现在有了:

With the help of Albert, I now have:

HRESULT hr = GetActiveObject(SlaveGUID, NULL, (IUnknown**)&pUnk); // SlaveGUID is correct,
									  // hr = 0;

hr = pUnk->QueryInterface( IID_IClassFactory, (void**)&ppv );       // hr = 0, ppv gets
Cbcrshimcontrol *ptrClass = (Cbcrshimcontrol *) ppv;		          // address
ptrClass->MidiOutFromMaster((DWORD) 0x27);                            // IDE populating -> with methods including 
   									   //MidiOutFromMaster. Home free? Not so much.
									  // Now some unresolved externals. :-(

Creating library .\Debug/bcr_18_PCEQ_SS_control.lib and object .\Debug/bcr_18_PCEQ_SS_control.exp

bcr_18_PCEQ_SS_control.obj : error LNK2028: unresolved token (0A000316) "public: static void __cdecl Cbcrshimcontrol::MidiOutFromMaster(unsigned long)" (?MidiOutFromMaster@Cbcrshimcontrol@@

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