参数个数可变、而且类型不固定，这样的函数怎么调用？

[flamkuavos]

有一个微软提供的函数:

InvokeHelper(DWORD dwDisp, BYTE *pbParamInfo, ...);
// pbParamInfo是省略号所表示的变参的类型信息的字符数组指针，
// 后面的变参（省略号），数目（最多需要12个）和类型都不确定，可以是
// short、double和CString（LPCTSTR）。如果仅仅是数值，那就好办
// 了，关键是有字符串。我试过把这3种类型都转成char*，但传进去总
// 是有问题

变参的数目、类型和具体的值我都可以知道，当然，都是动态的从一个列表中取出来的，现在我要把这些个数、类型都不固定的变量传进InvokeHelper这个函数，就是在省略号的地方。

都强制转换成char*类型才能在代码中用12行调用InvokeHelper的语句来写，但都不对，传进去的short型可能变成负数，字符串也可能是乱码。所以，似乎只有原汁原味的类型传进去才对。
这个代码，我想不出来可以怎么写了，请帮我看看，谢谢！

[Eleven]

C/C++ 可变参数表的深层探索

[oyljerry]

void InvokeHelper( DISPID dwDispID, WORD wFlags, VARTYPE vtRet, void* pvRet, const BYTE* pbParamInfo, ... );
　　说明：
　　Call this member function to invoke the OLE control method or property specified by dwDispID, in the context specified by wFlags.
　　其中参数：
　　dwDispID：
　　//Identifies the method or property to be invoked. This value is usually supplied by Component Gallery.
　　wFlags：可以为下面些值，指明调用InvokeHelper的目的。
　　//[ DISPATCH_METHOD ] The member is invoked as a method. If a property has the same name, both this and the DISPATCH_PROPERTYGET flag may be set.
　　[ DISPATCH_PROPERTYGET ] The member is retrieved as a property or data member.
　　[ DISPATCH_PROPERTYPUT ] The member is changed as a property or data member.
　　[ DISPATCH_PROPERTYPUTREF ] The member is changed by a reference assignment, rather than a value assignment. This flag is valid only when the property accepts a reference to an object.
　　vtRet：
　　//Specifies the type of the return value.
　　VT_EMPTY void
　　VT_I2 short
　　VT_I4 long
　　VT_R4 float
　　VT_R8 double
　　VT_CY CY
　　VT_DATE DATE
　　VT_BSTR BSTR
　　VT_DISPATCH LPDISPATCH
　　VT_ERROR SCODE
　　VT_BOOL BOOL
　　VT_VARIANT VARIANT
　　VT_UNKNOWN LPUNKNOWN
　　pvRet：
　　//Address of the variable that will that will receive the property value or return value. It must match the type specified by vtRet.
　　pbParamInfo：一般都设置为NULL
　　//Pointer to a null-terminated string of bytes specifying the types of the parameters following pbParamInfo.
　　specifies the types of the parameters passed to the method or property.
　　...：
　　//Variable List of parameters, of types specified in pbParamInfo.

[oyljerry]

需要指定对应的类型告诉函数.

[jyh_baoding]

可变参数的处理

[flamkuavos]

l楼的兔子部长，你的解答很好，谢谢你，我看了，但是还不一定是我要的答案

你介绍的文章，看明白可以知道怎么写变参函数，以及它的取参方法，但我现在的难题发生在调用上，而且面对字符串参数时，这个变参的指针怎么移动的，还是个问题，我还得研究研究。不过你的文章很有帮助啦，基础嘛。

[珍惜生命远离CPP]

[flamkuavos]

http://topic.csdn.net/u/20110106/09/f6781818-bfba-4e1c-82cd-79e64050fc42.html
是ls的正确回答，所以给分

[ryfdizuo]

InvokeHelper的用法：

void CMSComm::SetCDHolding(BOOL bNewValue)
{
	static BYTE parms[] =
		VTS_BOOL;
	InvokeHelper(0x1, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 bNewValue);
}

BOOL CMSComm::GetCDHolding()
{
	BOOL result;
	InvokeHelper(0x1, DISPATCH_PROPERTYGET, VT_BOOL, (void*)&result, NULL);
	return result;
}

void CMSComm::SetCommID(long nNewValue)
{
	static BYTE parms[] =
		VTS_I4;
	InvokeHelper(0x3, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 nNewValue);
}

long CMSComm::GetCommID()
{
	long result;
	InvokeHelper(0x3, DISPATCH_PROPERTYGET, VT_I4, (void*)&result, NULL);
	return result;
}

void CMSComm::SetCommPort(short nNewValue)
{
	static BYTE parms[] =
		VTS_I2;
	InvokeHelper(0x4, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 nNewValue);
}

short CMSComm::GetCommPort()
{
	short result;
	InvokeHelper(0x4, DISPATCH_PROPERTYGET, VT_I2, (void*)&result, NULL);
	return result;
}

void CMSComm::SetCTSHolding(BOOL bNewValue)
{
	static BYTE parms[] =
		VTS_BOOL;
	InvokeHelper(0x5, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 bNewValue);
}

BOOL CMSComm::GetCTSHolding()
{
	BOOL result;
	InvokeHelper(0x5, DISPATCH_PROPERTYGET, VT_BOOL, (void*)&result, NULL);
	return result;
}

void CMSComm::SetDSRHolding(BOOL bNewValue)
{
	static BYTE parms[] =
		VTS_BOOL;
	InvokeHelper(0x7, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 bNewValue);
}

BOOL CMSComm::GetDSRHolding()
{
	BOOL result;
	InvokeHelper(0x7, DISPATCH_PROPERTYGET, VT_BOOL, (void*)&result, NULL);
	return result;
}

void CMSComm::SetDTREnable(BOOL bNewValue)
{
	static BYTE parms[] =
		VTS_BOOL;
	InvokeHelper(0x9, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 bNewValue);
}

BOOL CMSComm::GetDTREnable()
{
	BOOL result;
	InvokeHelper(0x9, DISPATCH_PROPERTYGET, VT_BOOL, (void*)&result, NULL);
	return result;
}

void CMSComm::SetHandshaking(long nNewValue)
{
	static BYTE parms[] =
		VTS_I4;
	InvokeHelper(0xa, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 nNewValue);
}

long CMSComm::GetHandshaking()
{
	long result;
	InvokeHelper(0xa, DISPATCH_PROPERTYGET, VT_I4, (void*)&result, NULL);
	return result;
}

void CMSComm::SetInBufferSize(short nNewValue)
{
	static BYTE parms[] =
		VTS_I2;
	InvokeHelper(0xb, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 nNewValue);
}

short CMSComm::GetInBufferSize()
{
	short result;
	InvokeHelper(0xb, DISPATCH_PROPERTYGET, VT_I2, (void*)&result, NULL);
	return result;
}

void CMSComm::SetInBufferCount(short nNewValue)
{
	static BYTE parms[] =
		VTS_I2;
	InvokeHelper(0xc, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 nNewValue);
}

short CMSComm::GetInBufferCount()
{
	short result;
	InvokeHelper(0xc, DISPATCH_PROPERTYGET, VT_I2, (void*)&result, NULL);
	return result;
}

void CMSComm::SetBreak(BOOL bNewValue)
{
	static BYTE parms[] =
		VTS_BOOL;
	InvokeHelper(0xd, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 bNewValue);
}

BOOL CMSComm::GetBreak()
{
	BOOL result;
	InvokeHelper(0xd, DISPATCH_PROPERTYGET, VT_BOOL, (void*)&result, NULL);
	return result;
}

void CMSComm::SetInputLen(short nNewValue)
{
	static BYTE parms[] =
		VTS_I2;
	InvokeHelper(0xe, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 nNewValue);
}

short CMSComm::GetInputLen()
{
	short result;
	InvokeHelper(0xe, DISPATCH_PROPERTYGET, VT_I2, (void*)&result, NULL);
	return result;
}

void CMSComm::SetNullDiscard(BOOL bNewValue)
{
	static BYTE parms[] =
		VTS_BOOL;
	InvokeHelper(0x10, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 bNewValue);
}

BOOL CMSComm::GetNullDiscard()
{
	BOOL result;
	InvokeHelper(0x10, DISPATCH_PROPERTYGET, VT_BOOL, (void*)&result, NULL);
	return result;
}

void CMSComm::SetOutBufferSize(short nNewValue)
{
	static BYTE parms[] =
		VTS_I2;
	InvokeHelper(0x11, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 nNewValue);
}

short CMSComm::GetOutBufferSize()
{
	short result;
	InvokeHelper(0x11, DISPATCH_PROPERTYGET, VT_I2, (void*)&result, NULL);
	return result;
}

void CMSComm::SetOutBufferCount(short nNewValue)
{
	static BYTE parms[] =
		VTS_I2;
	InvokeHelper(0x12, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 nNewValue);
}

short CMSComm::GetOutBufferCount()
{
	short result;
	InvokeHelper(0x12, DISPATCH_PROPERTYGET, VT_I2, (void*)&result, NULL);
	return result;
}

void CMSComm::SetParityReplace(LPCTSTR lpszNewValue)
{
	static BYTE parms[] =
		VTS_BSTR;
	InvokeHelper(0x13, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 lpszNewValue);
}

CString CMSComm::GetParityReplace()
{
	CString result;
	InvokeHelper(0x13, DISPATCH_PROPERTYGET, VT_BSTR, (void*)&result, NULL);
	return result;
}

void CMSComm::SetPortOpen(BOOL bNewValue)
{
	static BYTE parms[] =
		VTS_BOOL;
	InvokeHelper(0x14, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 bNewValue);
}

BOOL CMSComm::GetPortOpen()
{
	BOOL result;
	InvokeHelper(0x14, DISPATCH_PROPERTYGET, VT_BOOL, (void*)&result, NULL);
	return result;
}

void CMSComm::SetRThreshold(short nNewValue)
{
	static BYTE parms[] =
		VTS_I2;
	InvokeHelper(0x15, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 nNewValue);
}

short CMSComm::GetRThreshold()
{
	short result;
	InvokeHelper(0x15, DISPATCH_PROPERTYGET, VT_I2, (void*)&result, NULL);
	return result;
}

void CMSComm::SetRTSEnable(BOOL bNewValue)
{
	static BYTE parms[] =
		VTS_BOOL;
	InvokeHelper(0x16, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 bNewValue);
}

BOOL CMSComm::GetRTSEnable()
{
	BOOL result;
	InvokeHelper(0x16, DISPATCH_PROPERTYGET, VT_BOOL, (void*)&result, NULL);
	return result;
}

void CMSComm::SetSettings(LPCTSTR lpszNewValue)
{
	static BYTE parms[] =
		VTS_BSTR;
	InvokeHelper(0x17, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 lpszNewValue);
}

CString CMSComm::GetSettings()
{
	CString result;
	InvokeHelper(0x17, DISPATCH_PROPERTYGET, VT_BSTR, (void*)&result, NULL);
	return result;
}

void CMSComm::SetSThreshold(short nNewValue)
{
	static BYTE parms[] =
		VTS_I2;
	InvokeHelper(0x18, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 nNewValue);
}

short CMSComm::GetSThreshold()
{
	short result;
	InvokeHelper(0x18, DISPATCH_PROPERTYGET, VT_I2, (void*)&result, NULL);
	return result;
}

void CMSComm::SetOutput(const VARIANT& newValue)
{
	static BYTE parms[] =
		VTS_VARIANT;
	InvokeHelper(0x19, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 &newValue);
}

VARIANT CMSComm::GetOutput()
{
	VARIANT result;
	InvokeHelper(0x19, DISPATCH_PROPERTYGET, VT_VARIANT, (void*)&result, NULL);
	return result;
}

void CMSComm::SetInput(const VARIANT& newValue)
{
	static BYTE parms[] =
		VTS_VARIANT;
	InvokeHelper(0x1a, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 &newValue);
}

VARIANT CMSComm::GetInput()
{
	VARIANT result;
	InvokeHelper(0x1a, DISPATCH_PROPERTYGET, VT_VARIANT, (void*)&result, NULL);
	return result;
}

void CMSComm::SetCommEvent(short nNewValue)
{
	static BYTE parms[] =
		VTS_I2;
	InvokeHelper(0x1b, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 nNewValue);
}

short CMSComm::GetCommEvent()
{
	short result;
	InvokeHelper(0x1b, DISPATCH_PROPERTYGET, VT_I2, (void*)&result, NULL);
	return result;
}

void CMSComm::SetEOFEnable(BOOL bNewValue)
{
	static BYTE parms[] =
		VTS_BOOL;
	InvokeHelper(0x1c, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 bNewValue);
}

BOOL CMSComm::GetEOFEnable()
{
	BOOL result;
	InvokeHelper(0x1c, DISPATCH_PROPERTYGET, VT_BOOL, (void*)&result, NULL);
	return result;
}

void CMSComm::SetInputMode(long nNewValue)
{
	static BYTE parms[] =
		VTS_I4;
	InvokeHelper(0x1d, DISPATCH_PROPERTYPUT, VT_EMPTY, NULL, parms,
		 nNewValue);
}

long CMSComm::GetInputMode()
{
	long result;
	InvokeHelper(0x1d, DISPATCH_PROPERTYGET, VT_I4, (void*)&result, NULL);
	return result;
}