procedure Tfrmmain.FormCreate(Sender: TObject);
var
TempWSAData: TWSAData;
optval: integer;
begin
// 初始化SOCKET
if WSAStartup($101, TempWSAData)=1 then
showmessage('StartUp Error!');
s := Socket(AF_INET, SOCK_DGRAM, 0);
if (s = INVALID_SOCKET) then //Socket创建失败
begin
showmessage(inttostr(WSAGetLastError())+' Socket创建失败');
CloseSocket(s);
//exit;
end;
//发送方SockAddr绑定
addr.sin_family := AF_INET;
addr.sin_addr.S_addr := INADDR_ANY;
addr.sin_port := htons(UDPPORT);
if Bind(s, addr, sizeof(addr)) <> 0 then
begin
showmessage('bind fail');
end;
optval:= 1;
if setsockopt(s,SOL_SOCKET,SO_BROADCAST,pchar(@optval),sizeof(optval)) = SOCKET_ERROR then
begin
showmessage('无法进行UDP广播');
end;
{mreq.imr_multiaddr.S_addr := INADDR_ALLHOSTS_GROUP;
mreq.imr_interface.S_addr := INADDR_ANY;
if setsockopt(s,IPPROTO_IP,IP_ADD_MEMBERSHIP,pchar(@mreq),sizeof(mreq)) = SOCKET_ERROR then
begin
showmessage('无法进行UDP组播');
end;}
procedure Tfrmmain.FormClose(Sender: TObject; var Action: TCloseAction);
begin
CloseSocket(s);
end;
procedure Tfrmmain.ReadData(var Message: TMessage);
var
buffer: Array [1..4096] of char;
len: integer;
flen: integer;
Event: word;
value: string;
begin
flen:=sizeof(FSockAddrIn);
FSockAddrIn.SIn_Port := htons(UDPPORT);
Event := WSAGetSelectEvent(Message.LParam);
if Event = FD_READ then
begin
len := recvfrom(s, buffer, sizeof(buffer), 0, FSockAddrIn, flen);
value := copy(buffer, 1, len);
Memo1.Lines.add(value)
end;
end;
procedure Tfrmmain.SendData(Content: String);
var
value{,hostname}: string;
len: integer;
begin
FSockAddrIn.SIn_Addr.S_addr := INADDR_BROADCAST;
//FSockAddrIn.SIn_Addr.S_addr := inet_addr(pchar(Edit1.text)); //INADDR_BROADCAST; //INADDR_BROADCAST = -1 ?
value := Content;
len := sendto(s, value[1], Length(value), 0, FSockAddrIn, sizeof(FSockAddrIn));
if (WSAGetLastError() <> WSAEWOULDBLOCK) and (WSAGetLastError() <> 0) then
showmessage(inttostr(WSAGetLastError()));
if len = SOCKET_ERROR then
showmessage('send fail');
if len <> Length(value) then
showmessage('Not Send all');
end;
procedure Tfrmmain.Button1Click(Sender: TObject);
begin
senddata(Edit2.text);
end;