TSocket and UDP

[CHackbart 12]

Hi,

 

does somebody know if there is an example how to use the System.Net.Socket in combination with UDP? 

In the past I used synapse for this, but prefer in order to simplify my code use something which is officially supported on all platforms. 

What I did till now is the following: 

 

1. I collect the available network devices via:

procedure GetLocalIPs(iplist: TStrings; ipfamily: Integer);
var
  TcpSock: TTCPBlockSocket;
begin
    TcpSock := TTCPBlockSocket.create;
    case ipfamily of
      1 : TcpSock.family:=SF_IP4;
      2 : TcpSock.family:=SF_IP6;
    end;
    try
      TcpSock.ResolveNameToIP(TcpSock.LocalName, ipList);
    finally
      TcpSock.Free;
    end;
end;

 

2. I create a TUDPBlockSocket using: 

 Result := TUDPBlockSocket.Create();
 Result.bind(aIP, '0');
 Result.Connect('239.255.255.250', '1900');

resp.

Result := TUDPBlockSocket.Create();
  Result.EnableReuse(True);
  Result.bind(aIP, '1900');
  Result.MulticastTTL := 5;
  Result.AddMulticast('239.255.255.250');

3. These sockets where hosted in a TSocketList which I used to check if data is available using:

 

if FSocketList[0].GroupCanRead(fSockets, ftimeout, fActive) then

 

This worked well, but I would like to replace the whole code using the official Socket implementation instead. Anyhow I do not find a proper explanation how to use TSocket.Create(TSocketType.UDP, TEncoding.UTF8).

So if there is somebody who could point my nose to some code snippets, this would be great. I neither know how to get a list of the available network devices, nor how to bind the sockets or to send a request to socket I created first at step 2 

 

Cheers

Christian

 

Edited December 5, 2022 by CHackbart