Question

VARIANT的每个vt值所对应的数据类型是什么？

Answer 1

根据定义类型能看出来各个变量代表什么。
/* VARIANT STRUCTURE
*
* VARTYPE vt;
* WORD wReserved1;
* WORD wReserved2;
* WORD wReserved3;
* union {
* LONG VT_I4
* BYTE VT_UI1
* SHORT VT_I2
* FLOAT VT_R4
* DOUBLE VT_R8
* VARIANT_BOOL VT_BOOL
* SCODE VT_ERROR
* CY VT_CY
* DATE VT_DATE
* BSTR VT_BSTR
* IUnknown * VT_UNKNOWN
* IDispatch * VT_DISPATCH
* SAFEARRAY * VT_ARRAY
* BYTE * VT_BYREF|VT_UI1
* SHORT * VT_BYREF|VT_I2
* LONG * VT_BYREF|VT_I4
* FLOAT * VT_BYREF|VT_R4
* DOUBLE * VT_BYREF|VT_R8
* VARIANT_BOOL * VT_BYREF|VT_BOOL
* SCODE * VT_BYREF|VT_ERROR
* CY * VT_BYREF|VT_CY
* DATE * VT_BYREF|VT_DATE
* BSTR * VT_BYREF|VT_BSTR
* IUnknown ** VT_BYREF|VT_UNKNOWN
* IDispatch ** VT_BYREF|VT_DISPATCH
* SAFEARRAY ** VT_BYREF|VT_ARRAY
* VARIANT * VT_BYREF|VT_VARIANT
* PVOID VT_BYREF (Generic ByRef)
* CHAR VT_I1
* USHORT VT_UI2
* ULONG VT_UI4
* INT VT_INT
* UINT VT_UINT
* DECIMAL * VT_BYREF|VT_DECIMAL
* CHAR * VT_BYREF|VT_I1
* USHORT * VT_BYREF|VT_UI2
* ULONG * VT_BYREF|VT_UI4
* INT * VT_BYREF|VT_INT
* UINT * VT_BYREF|VT_UINT
* }

自己查一下MSDN，或者看一下oaidl.h。写的都挺详细的。