🚀 go-pugleaf

"Remy Lebeau (TeamB)" <no.spam@no.spam.com> schrieb im
 Newsbeitrag news:41955ff6@newsgroups.borland.com...

>
> If you are dynamically loading the DLL via LoadLibrary(), then yes.  You
> will, of course, have to make sure that when you use GetProcAddress() to
> retreive a function pointer, that the pointer is not returned as NULL before
> you try to call the function.  Some WinInet functions are not implemented on
> all OS versions.

OK, i check now:  if(InternetGetConnectedStatePtr != NULL)


>
> True, although you don't need to make thousands of calls.  You should only
> call LoadLibrary() once, and keep the DLL loaded for the entire duration
> that you are going to use it, and then call FreeLibrary() when you are not
> using the DLL anymore.  As for GetProcAddress(), you only have to call it
> once for each individual function that you are interested in.  Are you
> planning on call a thousand separate WinInet functions?  I doubt it.

OK..what do you think of this usage:

/**************************************************/
#include <WININET.h>

HMODULE wininet_hand;

typedef BOOL WINAPI (*FuncPtr)(DWORD* flags, DWORD reserved);

__fastcall TfrmMainUnit::TfrmMainUnit(TComponent* Owner) : TForm(Owner)
{
    wininet_hand = LoadLibrary("WININET.DLL");
}

void __fastcall TfrmMainUnit::Button1Click(TObject *Sender)
{
    FuncPtr InternetGetConnectedStatePtr;

    if(wininet_hand)
    {
      InternetGetConnectedStatePtr = (FuncPtr) GetProcAddress(wininet_hand,
"InternetGetConnectedState");

      if(InternetGetConnectedStatePtr != NULL)
      {
        DWORD flags;

        if(InternetGetConnectedStatePtr(&flags, 0))
        {
          char s[1024] = "Internet connection ";

          if(flags & INTERNET_CONNECTION_LAN) lstrcat(s, "is by local area
network");
          else if (flags & INTERNET_CONNECTION_MODEM) lstrcat(s, "is by modem");
          else if (flags & INTERNET_CONNECTION_PROXY) lstrcat(s, "is by proxy");
          else lstrcpy(s, "Not sure how the internet connection is made");
          ShowMessage(s);
        }
        else ShowMessage("InternetGetConnectedState call failed");
      }
      else ShowMessage("InternetGetConnectedState function not found");
    }
    else  ShowMessage("Unable to load WinInet.DLL");
}

__fastcall TfrmMainUnit::~TfrmMainUnit()
{
   FreeLibrary(wininet_hand);
}
/**************************************************/

is this ok...?

>
> On the other hand, if you do statically link to the lib file, then not only
> does the DLL itself have to exist, but so does every individual function
> that your code calls.  If you run your program on a system that does not
> have every single WinInet function that your code calls statically, then
> your program will fail to start at all.

TRUE !! i didn't thought about that, very good catch Remy !!!

>
> Then LoadLibrary() and GetProcAddress() are your only option.  Of course,
> had you been using BCB 5 or 6, you could make use of their Delay-Load
> mechanism to statically link to the DLL functions in your code while still
> providing run-time loading of the DLL when needed.  A very nice feature to
> use if you have it available.
>
>
> Gambit

still have to fight with BCB 3..this will only be possible for me in the
next project that will be finally developed under BCB 6 :-)


Oren