完成端口写的一个小的测试，没有看懂。先写个给高手帮我看下。

Question

Server端:
var
  Form1: TForm1;
  iHandle: THandle;
  GlobalLock: TCriticalSection;
    
implementation{$R *.dfm}procedure TForm1.Button1Click(Sender: TObject);
begin
  iHandle:= CreateIoCompletionPort(INVALID_HANDLE_VALUE, 0, 0, 0);
end;procedure TForm1.Button2Click(Sender: TObject);
var
  Addr: TSockAddr;
begin
  iSender:= WSASocket(AF_INET, SOCK_DGRAM, 0, nil, 0, WSA_FLAG_OVERLAPPED);
  Addr.sin_family:= AF_INET;
  Addr.sin_port:= htons(4545);
  Addr.sin_addr.S_addr:= inet_addr('127.0.0.1');
  if Bind(iSender, @Addr, Sizeof(Addr)) <> 0 then
  begin
    ShowMessage('绑定出错');
  end;
  if iSender <> INVALID_SOCKET then
  begin
    if CreateIoCompletionPort(iSender, iHandle, 0, 0) <> 0 then
    begin
      tWorkThread.Create;
    end;
  end;
end;{ tWorkThread }constructor tWorkThread.Create;
begin
  inherited Create(True);
  FreeOnTerminate := true;
  Resume;
end;procedure tWorkThread.Execute;
var
  HandleData: PPerHandleData;
  byteRece, Key: DWORD;
  OperPosted: boolean;
  errCode: integer;
begin
  while not Terminated do
  begin
    if not GetQueuedCompletionStatus(iHandle, byteRece, Key, POverlapped(HandleData), INFINITE) then
    begin
      errCode:= GetLastError;
      if errCode = 6 then
        Terminate;
      Continue;
    end
    else
      begin
        GlobalLock.Enter;
        case HandleData.Statu of
        ssRecv:
          begin
            ShowMessage('Recv');
          end;
        ssSend:
          begin
            ShowMessage('Send');
          end;
        end;
        GlobalLock.Leave;
      end;      end;
end;procedure TForm1.FormCreate(Sender: TObject);
var
  wsaData: TWSAData;
begin
  WSAStartup(makeword(2, 0), wsaData);
end;procedure TForm1.FormDestroy(Sender: TObject);
begin
  WSACleanup;
end;initialization
  GlobalLock := TCriticalSection.Create;
finalization
  GlobalLock.Free;end.Client端：
procedure TForm1.FormCreate(Sender: TObject);
var
  wsaData: TWSAData;
begin
  WSAStartup(makeword(2, 0), wsaData);
end;procedure TForm1.FormDestroy(Sender: TObject);
begin
  WSAcleanup;
end;procedure TForm1.Button1Click(Sender: TObject);
var
  addrin: TSockAddr;
  tmpPacket: array [0..8191] of byte;
begin
  iSender:= Socket(AF_INET, SOCK_DGRAM, 0);
  addrin.sin_family:= AF_INET;
  addrin.sin_port:= htons(4540);
  addrin.sin_addr.S_addr:= inet_addr('127.0.0.1');
  if Bind(iSender, @addrin, sizeof(addrin)) <> 0 then
    ShowMessage('绑定出错')
  else
    begin
      Sendto(iSender, tmpPacket, 8192, 0, addrin, sizeof(addrin));
    end;
end;

Answer 1

给你改了一下：
const
  BUFFER_SIZE = 4096;type
  YServerAction = ( saSend, saRecv, saClose, saSendAndClose, saBroadcast );
  //
  //扩展的WSAOVERLAPPED，即"Overlapped"(单句柄数据)
  //
  YPerOverlappedEx = record
    Overlap  : WSAOVERLAPPED;
    DataInf  : WSABUF;
    Buf      : Array [0..BUFFER_SIZE-1] of Char;
    Action   : YServerAction;
  end;
  PPerOverlappedEx = ^YPerOverlappedEx;  YWorkThread = class(TThread)
  private
    FCompletPort  : THandle;
  protected
    procedure Execute; override;
  end;var
  Form1: TForm1;
  iocp : THandle;
  sock : TSocket;
  workthread  : YWorkThread;implementation{$R *.dfm}
procedure YWorkThread.Execute;
var
  dwTransferd : DWORD;
  pOverlapEx  : PPerOverlappedEx;
  sock        : TSocket;
  dwTransfer, dwFlag : DWORD;
begin
  while (not Terminated) do
  begin
    dwTransferd := 0;
    GetQueuedCompletionStatus( FCompletPort, dwTransferd, DWORD(sock),
        POVERLAPPED(pOverlapEx), 1000 );    if ( dwTransferd = 0 ) then
    begin
      if ( Sock = 0 ) or ( pOverlapEx = nil ) then
           continue;
    end;    case pOverlapEx^.Action of
      saRecv : //完成了接收数据任务(pOverlapEx内有接收到的数据)
      begin
        messagebox(0,'recved','iocp',mb_ok);        fillChar( pOverlapEx^.Overlap, sizeof(WSAOVERLAPPED), 0 );
        FillChar( pOverlapEx^.Buf[0], BUFFER_SIZE, 0 );
        pOverlapEx^.DataInf.len := BUFFER_SIZE;
        pOverlapEx^.DataInf.buf := pOverlapEx^.Buf;
        pOverlapEx^.Action := saRecv;
        dwFlag := 0;
        WSARecv( sock, @(pOverlapEx^.DataInf), 1, dwTransfer, dwFlag,
           @(pOverlapEx^.Overlap), nil );
      end;      saSend : ;//完成了发送数据任务
    end; //case pOverlapEx^.Action of
  end; //while not terminated
end;procedure TForm1.FormCreate(Sender: TObject);
var
  wsa : TWSAData;
begin
  WSAStartup( $0202, wsa );
  ListBox1.Font.Name := 'Courier New';
  ListBox1.Font.Size := 9;
end;procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
begin
  WSACleanup;
end;procedure TForm1.Button1Click(Sender: TObject);
var
  Addr: TSockAddr;
  pOverlapEx : PPerOverlappedEx;
  dwTransfer, dwFlag : DWORD;
begin
  //先创建完成端口
  iocp := CreateIoCompletionPort(INVALID_HANDLE_VALUE, 0, 0, 0);  //再创建线程
  WorkThread := YWorkThread.Create( true );
  WorkThread.FCompletPort := iocp;
  WorkThread.FreeOnTerminate := true;
  WorkThread.Resume;  //再创建socket
  sock := Socket( AF_INET, SOCK_DGRAM, 0  );
  Addr.sin_family:= AF_INET;
  Addr.sin_port:= htons(4545);
  Addr.sin_addr.S_addr:= inet_addr('192.168.1.12');  if Bind( sock, @Addr, Sizeof(Addr) ) <> 0 then
  begin
    ShowMessage('绑定出错');
    closehandle( iocp );
    Exit;
  end;  //然后把socket和iocp绑定
  CreateIoCompletionPort( sock, iocp, sock, 0 );  //最后，要投递一个recv请求
  New( pOverlapEx );
  fillChar( pOverlapEx^.Overlap, sizeof(WSAOVERLAPPED), 0 );
  FillChar( pOverlapEx^.Buf[0], BUFFER_SIZE, 0 );
  pOverlapEx^.DataInf.len := BUFFER_SIZE;
  pOverlapEx^.DataInf.buf := pOverlapEx^.Buf;
  pOverlapEx^.Action := saRecv;  dwFlag := 0;
  WSARecv( sock, @(pOverlapEx^.DataInf), 1, dwTransfer, dwFlag,
           @(pOverlapEx^.Overlap), nil );
end;end.

Answer 2

呵呵，把两个地方的WSARecv改为WSARecvfrom罢 
len := sizeof(addr);
  fillchar(addr,len,0);
  WSARecvfrom( sock, @(pOverlapEx^.DataInf), 1, dwTransfer, dwFlag,
      @addr,@len,     @(pOverlapEx^.Overlap), nil );