DISPATCH_PROPERTYGET
The member is retrieved as a property or data member.
这是本文最关键的地址，如果你返回的值是一个COM对象，调用者会增加AddRef吗?不会，所以你需要自己添加计数，否则程序将很快崩溃
补充一条，js脚本在从C++本地语言获取对象时，IE js引擎的做法是，不会记住改对象地址，而是下次要用时重新取，这也就更需要注意引用计数这个问题了
Provides access to properties and methods exposed by an object. The dispatch functionDispInvokeprovides a standard implementation ofInvoke.
Syntax
C++
HRESULT Invoke( [in]DISPID dispIdMember, [in]REFIID riid, [in]LCID lcid, [in]WORD wFlags, [in, out]DISPPARAMS *pDispParams, [out]VARIANT *pVarResult, [out]EXCEPINFO *pExcepInfo, [out]UINT *puArgErr);
ParametersdispIdMember[in]
Identifies the member. UseGetIDsOfNamesor the object’s documentation to obtain the dispatch identifier.
riid[in]
Reserved for future use. Must be IID_NULL.
lcid[in]
The locale context in which to interpret arguments. Thelcidis used by theGetIDsOfNamesfunction, and is also passed toInvoketo allow the object to interpret its arguments specific to a locale.
Applications that do not support multiple national languages can ignore this parameter. For more information, refer toSupporting Multiple National LanguagesandExposing ActiveX Objects.
wFlags[in]
Flags describing the context of theInvokecall.
ValueMeaning
DISPATCH_METHOD
The member is invoked as a method. If a property has the same name, both this and the DISPATCH_PROPERTYGET flag can be set.
DISPATCH_PROPERTYGET
The member is retrieved as a property or data member.
这是本文最关键的地址，如果你返回的值是一个COM对象，，调用者会增加AddRef吗?不会，所以你需要自己添加计数，否则程序将很快崩溃
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.
pDispParams[in, out]
Pointer to a DISPPARAMS structure containing an array of arguments, an array of argument DISPIDs for named arguments, and counts for the number of elements in the arrays.
pVarResult[out]
Pointer to the location where the result is to be stored, or NULL if the caller expects no result. This argument is ignored if DISPATCH_PROPERTYPUT or DISPATCH_PROPERTYPUTREF is specified.
pExcepInfo[out]
Pointer to a structure that contains exception information. This structure should be filled in if DISP_E_EXCEPTION is returned. Can be NULL.
puArgErr[out]
The index within rgvarg of the first argument that has an error. Arguments are stored in pDispParams->rgvarg in reverse order, so the first argument is the one with the highest index in the array. This parameter is returned only when the resulting return value is DISP_E_TYPEMISMATCH or DISP_E_PARAMNOTFOUND. This argument can be set to null. For details, seeReturning Errors.
Return value
This method can return one of these values.
Return codeDescription
S_OK
Success.
DISP_E_BADPARAMCOUNT
The number of elements provided to DISPPARAMS is different from the number of arguments accepted by the method or property.
DISP_E_BADVARTYPE
One of the arguments in DISPPARAMS is not a valid variant type.
DISP_E_EXCEPTION
The application needs to raise an exception. In this case, the structure passed inpexcepinfoshould be filled in.
DISP_E_MEMBERNOTFOUND
The requested member does not exist.
DISP_E_NONAMEDARGS
This implementation ofIDispatchdoes not support named arguments.
DISP_E_OVERFLOW
One of the arguments in DISPPARAMS could not be coerced to the specified type.
DISP_E_PARAMNOTFOUND
One of the parameter IDs does not correspond to a parameter on the method. In this case,puArgErris set to the first argument that contains the error.
DISP_E_TYPEMISMATCH
One or more of the arguments could not be coerced. The index of the first parameter with the incorrect type within rgvarg is returned inpuArgErr.
DISP_E_UNKNOWNINTERFACE
The interface identifier passed in riid is not IID_NULL.
DISP_E_UNKNOWNLCID对于旅行，从来都记忆模糊。记不得都去了哪些地方，
