从Javascript访问NPAPI插件的属性

Question

Have a problem when try to get a value of a property via Javascript using a NPAPI plugin; During the debugging I see that all the chain of functions (HasProperty, HasMethod, and GetProperty) are called. More over I see that during calling GetProperty I set the new values into the result parameter. But after leaving GetProperty I get an exception and can't understand what the reason of it.

May FireFox call some additional functions which I forgot to initialize?

Thanks in advance

My code is:

// static function which calls Get_Property for the instance of CScriptableNPObject
bool CScriptableNPObject::NP_GetProperty(NPObject *npobj, NPIdentifier name, NPVariant *result)
{
    m_Logs.WriteLogs(10, _T("Enter the CScriptableNPObject::NP_GetProperty()"));

    return ((CScriptableNPObject *)npobj)->GetProperty(name, result);
}

// just converter name from NPIdentifier to char *
bool CScriptableNPObject::GetProperty(NPIdentifier name, NPVariant *result)
{
    NPUTF8 *pszProperty = m_pNPNFuncs->utf8fromidentifier(name);

    return GetProperty(pszProperty, result);
}

// checking the dictionary of properties, if property exists put its value into the result
bool CScriptableNPObject::GetProperty(NPUTF8 *pszProperty, NPVariant *result)
{
    VOID_TO_NPVARIANT(*result);

    JSPropertiesMap::iterator it = m_JSProperties.find(pszProperty);

    if (it == m_JSProperties.end())
        return false;

    NPUTF8 *pszNewPropertyValue = new NPUTF8[it->second->value.stringValue.UTF8Length + 1];
    sprintf(pszNewPropertyValue, it->second->value.stringValue.UTF8Characters);

    STRINGZ_TO_NPVARIANT(pszNewPropertyValue, *result);

    return true;
}

Answer 1

您需要使用NPN_MemAlloc() ：

NPUTF8* newValue = NPN_MemAlloc(length + 1);