COleDispatchDriver::InvokeHelper

Статья
10/16/2008

Calls the object method or property specified by dwDispID, in the context specified by wFlags.

void AFX_CDECL InvokeHelper(
   DISPID dwDispID,
   WORD wFlags,
   VARTYPE vtRet,
   void* pvRet,
   const BYTE* pbParamInfo,
      ... 
);

Параметры

dwDispID
Identifies the method or property to be invoked.
wFlags
Flags describing the context of the call to IDispatch::Invoke. . For a list of possible values, see the wFlags parameter in IDispatch::Invoke in the Windows SDK.
vtRet
Specifies the type of the return value. For possible values, see the Remarks section.
pvRet
Address of the variable that will receive the property value or return value. It must match the type specified by vtRet.
pbParamInfo
Pointer to a null-terminated string of bytes specifying the types of the parameters following pbParamInfo.
...
Variable list of parameters, of types specified in pbParamInfo.

Заметки

The pbParamInfo parameter specifies the types of the parameters passed to the method or property. The variable list of arguments is represented by ... in the syntax declaration.

Possible values for the vtRet argument are taken from the VARENUM enumeration. Possible values are as follows:

Symbol	Return Type
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

The pbParamInfo argument is a space-separated list of VTS_ constants. One or more of these values, separated by spaces (not commas), specifies the function's parameter list. Possible values are listed with the EVENT_CUSTOM macro.

This function converts the parameters to VARIANTARG values, then invokes the IDispatch::Invoke method. If the call to Invoke fails, this function will throw an exception. If the SCODE (status code) returned by IDispatch::Invoke is DISP_E_EXCEPTION, this function throws a COleException object; otherwise it throws a COleDispatchException.

For more information, see VARIANTARG, Implementing the IDispatch Interface, IDispatch::Invoke, and Structure of COM Error Codes in the Windows SDK.