请问，怎样才能用c实现com？在很多书上都是用c++。

Question

  
能不能给个简单的例子，或有关文档。谢谢

Answer 1

应该说， C 是不可能实现com 的,C 不是OOL ，  要知道，vtable 是 com  的基石。

Answer 2

no，只要你搞到com binary的格式，那么恭喜你你可以用c完全实现那样的binary格式，vtable 嘛，拿指针狂写就是了。其实就是重新实现一把COM，太 太难了。

Answer 3

哦很无聊,试下:#include <objbase.h>// {1BED467F-0934-4c7c-B657-472FEB0ED7F9}
static const GUID IID_ITestComWithC = 
{ 0x1bed467f, 0x934, 0x4c7c, { 0xb6, 0x57, 0x47, 0x2f, 0xeb, 0xe, 0xd7, 0xf9 } };// {AA38E64D-7812-4ed1-B0CC-1BA4B117E12C}
static const GUID CLSID_TestComWithC = 
{ 0xaa38e64d, 0x7812, 0x4ed1, { 0xb0, 0xcc, 0x1b, 0xa4, 0xb1, 0x17, 0xe1, 0x2c } };
BOOL APIENTRY DllMain( HANDLE h, DWORD w, LPVOID p )
{
    return TRUE;
}typedef struct ITestComWithC_Vtbl
{
    BEGIN_INTERFACE
     
/* IUnknown */    HRESULT ( STDMETHODCALLTYPE __RPC_FAR *QueryInterface )();
    
    ULONG ( STDMETHODCALLTYPE __RPC_FAR *AddRef )();
    
    ULONG ( STDMETHODCALLTYPE __RPC_FAR *Release )(); STDMETHOD( set_TestProp )();
STDMETHOD( get_TestProp )();
STDMETHOD( TestMethod1  )();
    
    END_INTERFACE
} ITestComWithC_Vtbl;typedef struct ITestComWithC_Impl_Simple
{
CONST_VTBL struct ITestComWithC_Vtbl* lpVtbl;
ULONG m_refcount;
long m_prop;
} ITestComWithC_Impl_Simple;STDMETHODIMP ITestComWithC_Impl_Simple_QI( IUnknown* This , REFIID riid , void** ppv )
{
if( !memcmp( &IID_IUnknown , riid , sizeof( GUID ) ) ||
!memcmp( &IID_ITestComWithC , riid , sizeof( GUID ) ) )
{
This->lpVtbl->AddRef( This );
*ppv = (void*)This;
return S_OK;
}
*ppv = NULL; 
return E_NOINTERFACE;
}STDMETHODIMP_(ULONG) ITestComWithC_Impl_Simple_Addref( ITestComWithC_Impl_Simple* This )
{
InterlockedIncrement( &This->m_refcount );
return This->m_refcount;
}STDMETHODIMP_(ULONG) ITestComWithC_Impl_Simple_Release( ITestComWithC_Impl_Simple* This )
{
if( 0 == InterlockedDecrement( &This->m_refcount ) )
{
CoTaskMemFree( This );
return 0;
}
return This->m_refcount;
}STDMETHODIMP ITestComWithC_Impl_Simple_set_Prop( ITestComWithC_Impl_Simple* This , long a )
{
This->m_prop = a;
return S_OK;
}STDMETHODIMP ITestComWithC_Impl_Simple_get_Prop( ITestComWithC_Impl_Simple* This , long* a )
{
if( !a ) return E_INVALIDARG;
*a = This->m_prop; return S_OK;
}STDMETHODIMP ITestComWithC_Impl_Simple_TestMethod1( ITestComWithC_Impl_Simple* This , long a , long b , long* c )
{
if( !c ) return E_INVALIDARG;
*c = a + b + This->m_prop;
return S_OK;
}static CONST_VTBL ITestComWithC_Vtbl vtbl_TestComWithC = 
{
ITestComWithC_Impl_Simple_QI,
ITestComWithC_Impl_Simple_Addref,
ITestComWithC_Impl_Simple_Release,
ITestComWithC_Impl_Simple_set_Prop,
ITestComWithC_Impl_Simple_get_Prop,
ITestComWithC_Impl_Simple_TestMethod1
};HRESULT  STDMETHODCALLTYPE SFI_QueryInterface( 
            IClassFactory __RPC_FAR * This,
            /* [in] */ REFIID riid,
            /* [iid_is][out] */ void __RPC_FAR *__RPC_FAR *ppvObject)
{
if( !memcmp( &IID_IClassFactory , riid , sizeof( GUID ) ) ||
!memcmp( &IID_IUnknown , riid , sizeof( GUID ) ) )
{
*ppvObject = This;
return S_OK;
}
return E_FAIL;
}
        
ULONG STDMETHODCALLTYPE __RPC_FAR SFI_AddRef( 
            IClassFactory __RPC_FAR * This)
{
return 1;
}
        
ULONG STDMETHODCALLTYPE __RPC_FAR SFI_Release ( 
            IClassFactory __RPC_FAR * This)
{
return 1;
}
        
/* [local] */ HRESULT STDMETHODCALLTYPE __RPC_FAR SFI_CreateInstance( 
            IClassFactory __RPC_FAR * This,
            /* [unique][in] */ IUnknown __RPC_FAR *pUnkOuter,
            /* [in] */ REFIID riid,
            /* [iid_is][out] */ void __RPC_FAR *__RPC_FAR *ppvObject)
{
if( pUnkOuter )
return E_FAIL;
if( !memcmp( riid , &IID_IUnknown , sizeof( GUID ) ) ||
!memcmp( riid , &IID_ITestComWithC , sizeof( GUID ) ) )
{
ITestComWithC_Impl_Simple *pThis = CoTaskMemAlloc( sizeof( ITestComWithC_Impl_Simple ) );
if( !pThis ) return E_OUTOFMEMORY;
pThis->lpVtbl = &vtbl_TestComWithC;
pThis->m_prop = 0;
pThis->m_refcount = 1;
*ppvObject = pThis;
return S_OK;
}
return E_FAIL;
}        
/* [local] */ HRESULT STDMETHODCALLTYPE __RPC_FAR SFI_LockServer( 
            IClassFactory __RPC_FAR * This,
            /* [in] */ BOOL fLock)
{
return S_OK;
}static IClassFactoryVtbl vtbl_IFC = 
{
SFI_QueryInterface,
SFI_AddRef,
SFI_Release,
SFI_CreateInstance,
SFI_LockServer
};STDAPI DllGetClassObject(REFCLSID rclsid, REFIID riid, LPVOID* ppv)
{
static IClassFactory icf = { &vtbl_IFC }; if( !memcmp( rclsid , &CLSID_TestComWithC , sizeof( GUID ) ) &&
!memcmp( riid , &IID_IClassFactory , sizeof( GUID ) ) )
{
*ppv = &icf;
return S_OK;
} return CLASS_E_CLASSNOTAVAILABLE;
}STDAPI DllCanUnloadNow(void)
{
return S_FALSE;
}

Answer 4

idl 文件 :import "oaidl.idl";
import "ocidl.idl";[
uuid(03F1CF27-F63E-418f-8C64-F64FA20362DC),
version(1.0)
]
library libTestComWithC
{
importlib("stdole32.tlb");
importlib("stdole2.tlb"); [
object,
uuid(1BED467F-0934-4c7c-B657-472FEB0ED7F9),
pointer_default(unique)
]
interface ITestComWithC : IUnknown
{
HRESULT set_TestProp( long a );
HRESULT get_TestProp( [out,retval]long* valRet );
HRESULT TestMethod1 ( long a , long b , [out,retval]long* valRet );
}; [uuid(AA38E64D-7812-4ed1-B0CC-1BA4B117E12C)]
coclass TestComWithC
{
interface ITestComWithC;
};
};-----------------------------------------------------------------------不想写 RegSvr && UnRegSvr 两个函数, 用 reg 文件:
Windows Registry Editor Version 5.00[HKEY_CLASSES_ROOT\CLSID\{AA38E64D-7812-4ed1-B0CC-1BA4B117E12C}]
@="TestCOMWithC Object"[HKEY_CLASSES_ROOT\CLSID\{AA38E64D-7812-4ed1-B0CC-1BA4B117E12C}\InprocServer32]
@="D:\\MyWork\\Demo\\TestCOMWithC\\Debug\\TestCOMWithC.dll"
"ThreadingModel"="Both"[HKEY_CLASSES_ROOT\CLSID\{AA38E64D-7812-4ed1-B0CC-1BA4B117E12C}\TypeLib]
@="{03F1CF27-F63E-418f-8C64-F64FA20362DC}"-----------------------------------------------------------------
.rc 里加上 1 TYPELIB "TestCOMWithC.tlb"

Answer 5

你可以参考 ATL 的源码

Answer 6

ATL是C++地哟.用C写COM还是满简单地哟

Answer 7

不懂。帮你顶。
问个问题。
blog的密码和登录CSDN的密码一样吗？我怎么登录不了Blog.

Answer 8

晕 系统在编译idl文件时就会同时生成C和CPP两个版本的接口定义嘛 代理兄不过Copy了一下

Answer 9

可以用C写COM的。
这样定义接口：
typedef struct tag_IUnknownVtbl
{
    HRESULT (__stdcall * pQueryInterface) (ComObject * this, REFIID iid, void ** ppvObject);
    LONG (__stdcall * pAddRef) (ComObject * this);
    LONG (__stdcall * pRelease) (ComObject * this);
} IUnknownVtbl;COM对象
typedef struct tag_ComObject
{
    IUnknownVtbl * pVtbl;
    /* 后面是自己定义的东西 */
} ComObject;取得COM对象：
IUnknown * GetObject()
{
    ComObject * pObj = (ComObject *)malloc(sizeof(ComOBject));
    pObj->pVtbl = (IUnknownVtbl *)malloc(sizeof(IUnknownVtbl));
    pObj->pVtbl.pQueryInterface = xxx;
    pObj->pVtbl.pAddRef = xxx;
    pObj->pVtbl.pRelease = xxx;
    return (IUnknown *)pObj;
}以上代码没有测试，仅供参考。

Answer 10

有本 c实现 com的书,英文版, 自己找找吧.