Introducing three different approaches to get local IP address in Delphi: Winsock, TIdStack and TIdIPWatch.
1) Get local IP address by Winsock
uses Winsock;
.
.
.
function GetLocalIP: string;
type
TaPInAddr = array [0..10] of PInAddr;
PaPInAddr = ^TaPInAddr;
var
phe: PHostEnt;
pptr: PaPInAddr;
Buffer: array [0..63] of Ansichar;
i: Integer;
GInitData: TWSADATA;
begin
WSAStartup($101, GInitData);
Result := '';
GetHostName(Buffer, SizeOf(Buffer));
phe := GetHostByName(Buffer);
if phe = nil then
Exit;
pptr := PaPInAddr(phe^.h_addr_list);
i := 0;
while pptr^[i] <> nil do
begin
Result := StrPas(inet_ntoa(pptr^[i]^));
Inc(i);
end;
WSACleanup;
end;
2) Get local IP address by TIDStack Indy class
uses IdStack;
.
.
.
function GetIP : String;
begin
TIdStack.IncUsage;
try
Result := GStack.LocalAddress;
finally
TIdStack.DecUsage;
end;
end
3) Get local IP address by TIdIpWatch Indy component
uses IdBaseComponent, IdComponent, IdIPWatch;
.
.
.
function GetLocalIp: string;
var
IPW: TIdIPWatch;
begin
IpW := TIdIPWatch.Create(nil);
try
if IpW.LocalIP <> '' then
Result := IpW.LocalIP;
finally
IpW.Free;
end;
end;