Network Enumeration(2)

This class introduces minor modifications to a Network enumeration article by Joerg Koenig.

Great! However, I wanted to use it locally within a function. The problem is that if you create a CNetSearch object within a function, you don't have access to it within a callback function called when a network resource is hit (the object itself is used to get properties of a network resource). Also, it is not possible to use one callback function in several situations (for example, search for network resources on application startup or updating network resources while application is running). Of course, these problems can always be solved using the original implementations.

To solve these problems, I introduced minor modifications (marked in bold):

Step 1:

This step contains all the modifications (done in netsearch.h include file).

template <class T>
class CNetSearch : public CNetwork {
    typedef BOOL (T::*NsFnc)(CNetSearch*, NETRESOURCE &, DWORD);
    T *m_pTheObject;
    NsFnc m_NsFnc;
    DWORD Data;
    public:
        CNetSearch() : m_pTheObject(0), m_NsFnc(0) {}
        void Create(T * pObj, NsFnc fnc, DWORD data) {
            ASSERT(pObj != 0);
            ASSERT(fnc != 0);
            m_pTheObject = pObj;
            m_NsFnc = fnc;
            Data = data;
        }
    protected: // overridables
        virtual BOOL OnHitResource(NETRESOURCE & rNetRC) {
            return (m_pTheObject->*m_NsFnc)(this,rNetRC,Data);
        }
    virtual BOOL NetError(DWORD dwErrorCode, LPCTSTR lpszFunction) {
        switch(dwErrorCode) {
            case ERROR_BAD_NETPATH:
            case ERROR_NO_NETWORK:
                // minor errors: continue enumeration
                return TRUE;
        }
        // serious error: break enumeration
        return CNetwork::NetError(dwErrorCode, lpszFunction);
    }
};
That's all.

Step 2:

To use this class now, all you have to do (let's assume that you are doing it locally from a function) is following:
 

// Update argument is FALSE on initial serch and TRUE when updating
void CMyDocument::scanNetworkMachines(BOOL update)
{
    CNetSearch<CMyDocument> netWalker;
    netWalker.Create(this,onNetResourceHit,(DWORD)update);
    netWalker.Enumerate();
}
BOOL CMyDocument::onNetResourceHit(CNetSearch<CMyDocument> *net, NETRESOURCE& res, DWORD data)
{
    int ndx;
    if (net->IsServer(res)) {
        CString str = net->GetRemoteName(res);
        for (int ndx = 0; str[ndx] == '\\' ; ++ndx) ;
        if (ndx)
            str = str.Mid(ndx);
        str.MakeUpper();
        if (data == 0) {
            // This is an initial scan !!!
            // For example, create TComputer object and add it to the list
        } else if (data == 1) {
            // This is an update !!!
            // For example, search for a TComputer object in a list and if not found,
            // create a new one and add it to the list.
        }
    }
    return TRUE;    // continue enumeration 
}
 

Last updated: 17 May 1998.



Comments

  • can this enumerate the network hierrachy

    Posted by Legacy on 07/02/2002 12:00am

    Originally posted by: TARundeep

    i want to have hierarchy of netwrok !! domains workgroup etc.

    Reply
Leave a Comment
  • Your email address will not be published. All fields are required.

Top White Papers and Webcasts

  • The nature of the financial services industry places a myriad of international compliance requirements on a company's IT team, as well as an expectation by its customers to deliver the high test levels of performance and reliability. To survive and thrive, businesses in the industry must not only keep pace with customer demand but gain competitive advantage. Those demands mean the IT team must be at the forefront of adopting emerging technologies

  • Thanks to wide spread cloud hosting and innovations small businesses can meet and exceed the legacy systems of goliath corporations. Explore the freedom to work how you want, with a phone system that will adapt to your evolving needs and actually save you lots of expense—read Get an Enterprise Phone System without High Cost and Complexity. The article clearly illustrates: The only hardware you'll need is phone equipment for advanced voice and fax. How to join all your employees, mobile devices, …

Most Popular Programming Stories

More for Developers

RSS Feeds

Thanks for your registration, follow us on our social networks to keep up-to-date