I want to work with Wifi with Delphi. How? - delphi

Question

In my Delphi (on Windows Xp) program I'd like to check available WiFi networks. Do you have any idea how to do it? Best is probably to use MS WlanScan API function but I did not found an example. Can someone help me?

Answer 1

You can use the Native Wifi API, available since Windows Vista and Windows XP. Older versions of Windows are not supported.
In this link you can find a very nice translation of the headers.
I wrote this code using these headers. Tested in Delphi 2007 and Windows Vista.
program DetectWifiUsingDelphi;
{$APPTYPE CONSOLE}
uses
Windows,
SysUtils,
//TypInfo,
nduWlanAPI in 'nduWlanAPI.pas',
nduWlanTypes in 'nduWlanTypes.pas';
function DOT11_AUTH_ALGORITHM_To_String( Dummy :Tndu_DOT11_AUTH_ALGORITHM):String;
begin
Result:='';
case Dummy of
DOT11_AUTH_ALGO_80211_OPEN : Result:= '80211_OPEN';
DOT11_AUTH_ALGO_80211_SHARED_KEY : Result:= '80211_SHARED_KEY';
DOT11_AUTH_ALGO_WPA : Result:= 'WPA';
DOT11_AUTH_ALGO_WPA_PSK : Result:= 'WPA_PSK';
DOT11_AUTH_ALGO_WPA_NONE : Result:= 'WPA_NONE';
DOT11_AUTH_ALGO_RSNA : Result:= 'RSNA';
DOT11_AUTH_ALGO_RSNA_PSK : Result:= 'RSNA_PSK';
DOT11_AUTH_ALGO_IHV_START : Result:= 'IHV_START';
DOT11_AUTH_ALGO_IHV_END : Result:= 'IHV_END';
end;
End;
function DOT11_CIPHER_ALGORITHM_To_String( Dummy :Tndu_DOT11_CIPHER_ALGORITHM):String;
Begin
Result:='';
case Dummy of
DOT11_CIPHER_ALGO_NONE : Result:= 'NONE';
DOT11_CIPHER_ALGO_WEP40 : Result:= 'WEP40';
DOT11_CIPHER_ALGO_TKIP : Result:= 'TKIP';
DOT11_CIPHER_ALGO_CCMP : Result:= 'CCMP';
DOT11_CIPHER_ALGO_WEP104 : Result:= 'WEP104';
DOT11_CIPHER_ALGO_WPA_USE_GROUP : Result:= 'WPA_USE_GROUP OR RSN_USE_GROUP';
//DOT11_CIPHER_ALGO_RSN_USE_GROUP : Result:= 'RSN_USE_GROUP';
DOT11_CIPHER_ALGO_WEP : Result:= 'WEP';
DOT11_CIPHER_ALGO_IHV_START : Result:= 'IHV_START';
DOT11_CIPHER_ALGO_IHV_END : Result:= 'IHV_END';
end;
End;
procedure Scan();
const
WLAN_AVAILABLE_NETWORK_INCLUDE_ALL_ADHOC_PROFILES =$00000001;
var
hClient : THandle;
dwVersion : DWORD;
ResultInt : DWORD;
pInterface : Pndu_WLAN_INTERFACE_INFO_LIST;
i : Integer;
j : Integer;
pAvailableNetworkList: Pndu_WLAN_AVAILABLE_NETWORK_LIST;
pInterfaceGuid : PGUID;
SDummy : string;
begin
ResultInt:=WlanOpenHandle(1, nil, #dwVersion, #hClient);
if ResultInt<> ERROR_SUCCESS then
begin
WriteLn('Error Open CLient'+IntToStr(ResultInt));
Exit;
end;
ResultInt:=WlanEnumInterfaces(hClient, nil, #pInterface);
if ResultInt<> ERROR_SUCCESS then
begin
WriteLn('Error Enum Interfaces '+IntToStr(ResultInt));
exit;
end;
for i := 0 to pInterface^.dwNumberOfItems - 1 do
begin
Writeln('Interface ' + pInterface^.InterfaceInfo[i].strInterfaceDescription);
WriteLn('GUID ' + GUIDToString(pInterface^.InterfaceInfo[i].InterfaceGuid));
Writeln('');
pInterfaceGuid:= #pInterface^.InterfaceInfo[pInterface^.dwIndex].InterfaceGuid;
ResultInt:=WlanGetAvailableNetworkList(hClient,pInterfaceGuid,WLAN_AVAILABLE_NETWORK_INCLUDE_ALL_ADHOC_PROFILES,nil,pAvailableNetworkList);
if ResultInt<> ERROR_SUCCESS then
begin
WriteLn('Error WlanGetAvailableNetworkList '+IntToStr(ResultInt));
Exit;
end;
for j := 0 to pAvailableNetworkList^.dwNumberOfItems - 1 do
Begin
WriteLn(Format('Profile %s',[WideCharToString(pAvailableNetworkList^.Network[j].strProfileName)]));
SDummy:=PChar(#pAvailableNetworkList^.Network[j].dot11Ssid.ucSSID);
WriteLn(Format('NetworkName %s',[SDummy]));
WriteLn(Format('Signal Quality %d ',[pAvailableNetworkList^.Network[j].wlanSignalQuality])+'%');
//SDummy := GetEnumName(TypeInfo(Tndu_DOT11_AUTH_ALGORITHM),integer(pAvailableNetworkList^.Network[j].dot11DefaultAuthAlgorithm)) ;
SDummy:=DOT11_AUTH_ALGORITHM_To_String(pAvailableNetworkList^.Network[j].dot11DefaultAuthAlgorithm);
WriteLn(Format('Auth Algorithm %s ',[SDummy]));
SDummy:=DOT11_CIPHER_ALGORITHM_To_String(pAvailableNetworkList^.Network[j].dot11DefaultCipherAlgorithm);
WriteLn(Format('Auth Algorithm %s ',[SDummy]));
Writeln('');
End;
end;
WlanCloseHandle(hClient, nil);
end;
begin
try
Scan();
Readln;
except
on E:Exception do
Writeln(E.Classname, ': ', E.Message);
end;
end.
alt text http://i33.tinypic.com/2z83ubt.jpg
Bye.

Answer 2

You can get to this also by performing a WMI query:
SELECT * FROM MSNdis_80211_ServiceSetIdentifier
If you are specifically looking for a delphi implementation, there is a WMI library available from Magenta Systems which includes complete source and may be freely used. The available download includes a compiled executable where you can try this query to see if it contains all of the data that you are looking for. The only disadvantage of this approach is that the WMI service must be running (it normally is so this is not that big of a problem).