不用TNNUDP并且不能用WINDOWS API函数如何写UDP通信程序？

[endure]

因为涉及不同OS平台不同语言问题，请大家帮忙，谢谢

[wfq_wanglan]

用socket就可以解决。

[zw84611]

unit udp;

interface

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs, winsock,
StdCtrls;

const
WM_SOCK = WM_USER + 1; //自定义windows消息
UDPPORT = 646; //设定UDP端口号

type
Tfrmmain = class(TForm)
Button1: TButton;
Edit1: TEdit;
Memo1: TMemo;
Edit2: TEdit;
Label1: TLabel;
Label2: TLabel;
Label3: TLabel;
procedure FormCreate(Sender: TObject);
procedure FormClose(Sender: TObject; var Action: TCloseAction);
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
s: TSocket;
addr: TSockAddr;
FSockAddrIn : TSockAddrIn;
//利用消息实时获知UDP消息
procedure ReadData(var Message: TMessage);
message WM_SOCK;
public
{ Public declarations }
procedure SendData(Content: String);
end;

var
frmmain: Tfrmmain;

implementation

{$R *.DFM}

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;}
WSAAsyncSelect(s, frmmain.Handle , WM_SOCK, FD_READ);
//接收端SockAddrIn设定
FSockAddrIn.SIn_Family := AF_INET;
FSockAddrIn.SIn_Port := htons(UDPPORT);
label3.Caption := '端口：'+inttostr(UDPPORT);
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 := 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;

end.

[newyj]

用控件也没问题的，控件只是封装接口而已，他不可能自己跑出一套协议来。
多种语言用就是了，我用delphi 连 bcb vc都没问题