IdUDPClient和IdUDPServer实现最简单的功能,但还是有问题,分不多了,望帮忙

Question

IdUDPClient和IdUDPServer实现最简单的功能,但还是有问题：Client和server都设了一样的端口，client设了server的IP,并且都active=true了
UDP的Client端有一定时器(每秒)读取收到的数据,如下:
procedure TForm1.Timer1Timer(Sender: TObject);
var
s:string;
begin
s:=IdUDPClient1.ReceiveString();
if s<>'' then
listbox1.Items.Add(s);
end;
UDP的server端有一按钮发送给client的数据:procedure TForm1.Button1Click(Sender: TObject);
begin
  IdUDPServer1.Send('192.100.100.121',9903,'abcd');
end;问题：
client收不到server的数据，而且定时器使程序变得很慢

Answer 1

用IdUDPClient实现数据的发送，用IdUDPServer接收数据，当IdUDPClient发送数据后，IdUDPServer的OnUDPRead事件中就可以接收到你发送的数据，根本没必要用timer。 建议你找个IdUDPClient和IdUDPServer控件demo例子好好看看。

Answer 2

客户端：
var
  cmd: string;
  ASize, TotalSize: Int64;
  AFileStream: TFileStream;
begin
  IdTCPClient1.Host := Edit1.Text; //连接主机
  IdTCPClient1.Port := StrToIntDef(Edit2.Text, 9925); //端口
  IdTCPClient1.Connect; //连接
  try
    IdTCPClient1.WriteLn('BEGIN'); //提示服务器开始接收
    cmd := IdTCPClient1.ReadLn;
    //以“|”符号分离文件名
    SaveDialog1.FileName := Copy(cmd, Pos('|', cmd) + 1, Length(cmd));
    if not SaveDialog1.Execute then
    begin
      IdTCPClient1.WriteLn('CANCEL'); //告诉服务器取消
      IdTCPClient1.Disconnect; //断开连接
      exit;
    end;
    TotalSize := StrToInt(Copy(cmd, 0, Pos('|', cmd) - 1)); //分离文件大小
    //建立文件流准备接收
    AFileStream := TFileStream.Create(SaveDialog1.FileName, fmCreate);
    try //循环开始接受
      repeat
        IdTCPClient1.WriteLn(IntToStr(AFileStream.Size));//发送当前传输的位置
        ASize := Min(TotalSize - AFileStream.Size, IdTCPClient1.RecvBufferSize);
        //选择剩余大小和缓冲区大小小的一个作为传输的大小
        IdTCPClient1.ReadStream(AFileStream, ASize); //接收流
        StatusBar1.SimpleText := Format('当前传输位置%d/大小%d', [AFileStream.Size, TotalSize]);
        Application.ProcessMessages;
      until AFileStream.Size = TotalSize; //大小一致了表示结束
    finally
      AFileStream.Free; //释放文件流
    end;
    IdTCPClient1.WriteLn('END'); //提示服务器传输完成
    StatusBar1.SimpleText := '传输完成...';
  except
    StatusBar1.SimpleText := '连接服务器失败或者对方已经中断传输！';
  end;
  IdTCPClient1.Disconne

Answer 3

服务器：
procedure Tfrm_Server.IdTCPServer1Execute(AThread: TIdPeerThread);
var
  cmd: string; //接收到客户端的字符串信息
  ASize: Integer; //需要传输的流大小
begin
  with AThread.Connection do //已经连街上的一个进程
  begin
    cmd := UpperCase(ReadLn); //客户端发送的命令字符串
    if cmd = 'BEGIN' then //开始传输
    begin
      //告诉远程传输文件的大小和文件名
      WriteLn(Format('%d|%s', [AFileStream.Size, ExtractFileName(Edit1.Text)]));
      StatusBar1.SimpleText := '准备传输...';
      Exit;
    end;
    if cmd = 'END' then
    begin //传输完成
      Button3.Click;
      StatusBar1.SimpleText := '传输完成...';
      Exit;
    end;
    if cmd = 'CANCEL' then
    begin //传输取消
      StatusBar1.SimpleText := '传输取消...';
      //保持传输状态
      Exit;
    end;
    //按照指定位置传输文件
    AFileStream.Seek(StrToInT(cmd), soFromBeginning); //转到文件流传输的位置
    ASize := Min(AFileStream.Size - AFileStream.Position, RecvBufferSize);
    //计算需要发送的大小，Min()函数在Math单元
    OpenWriteBuffer; //准备发送缓冲
    WriteStream(AFileStream, false, false, ASize);
    //注意这个函数的参数。
    CloseWriteBuffer; //结束发送缓冲
    StatusBar1.SimpleText := Format('当前传输位置%s/大小%d', [cmd, AFileStream.Size]);
    ProgressBar1.Position := ProgressBar1.Position + ASize;
  end;
end;

Answer 4

 Simple UDP client demo Verified;
  Indy 9:
    D7: 25th Oct 2004 Andy Neillans
}
unit UDPClientMain;interfaceuses
  Windows, Messages, Graphics, Controls, Forms, Dialogs, IdWinsock2,   stdctrls,
  SysUtils, Classes, IdBaseComponent, IdAntiFreezeBase, IdAntiFreeze,
  IdComponent, IdUDPBase, IdUDPClient, IdStack;type
  TUDPMainForm = class(TForm)
    SourceGroupBox: TGroupBox;
    HostNameLabel: TLabel;
    HostAddressLabel: TLabel;
    HostName: TLabel;
    HostAddress: TLabel;
    UDPAntiFreeze: TIdAntiFreeze;
    PortLabel: TLabel;
    Port: TLabel;
    DestinationLabel: TLabel;
    DestinationAddress: TLabel;
    BufferSizeLabel: TLabel;
    BufferSize: TLabel;
    UDPMemo: TMemo;
    SendButton: TButton;
    UDPClient: TIdUDPClient;
    procedure FormCreate(Sender: TObject);
    procedure SendButtonClick(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  UDPMainForm: TUDPMainForm;implementationconst
  HOSTNAMELENGTH = 80;
  RECIEVETIMEOUT = 5000; // milliseconds{$R *.DFM}procedure TUDPMainForm.FormCreate(Sender: TObject);
begin
  Randomize; // remove if you want reproducible results.
  HostName.Caption := UDPClient.LocalName;
  HostAddress.Caption := GStack.LocalAddress;
  Port.Caption := IntToStr(UDPClient.Port);
  DestinationAddress.Caption := UDPClient.Host;
  BufferSize.Caption := IntToStr(UDPClient.BufferSize);
  UDPClient.ReceiveTimeout := RECIEVETIMEOUT;
end;procedure TUDPMainForm.SendButtonClick(Sender: TObject);
var
  MessageID: Integer;
  ThisMessage: String;
  ReceivedString: String;
begin
  MessageID := Random(MAXINT);
  ThisMessage := 'Message: ' + IntToStr(MessageID);
  UDPMemo.Lines.Add('Sending ' + ThisMessage);
  UDPClient.Send(ThisMessage);
  ReceivedString := UDPClient.ReceiveString();
  if ReceivedString = '' then
    UDPMemo.Lines.Add('No response received from the server after ' + IntToStr(UDPClient.ReceiveTimeout) + ' millseconds.')
  else
    UDPMemo.Lines.Add('Received: ' + ReceivedString)
end;end.

Answer 5

Notes: Simple UDP server demoVerified:
  Indy 9:
    D7: 25th Oct 2004 Andy Neillans}unit UDPServerMain;interfaceuses
  Windows, Messages, Graphics, Controls, Forms, Dialogs, IdWinsock2, stdctrls,
  SysUtils, Classes, IdBaseComponent, IdAntiFreezeBase, IdAntiFreeze,
  IdComponent, IdUDPBase, IdUDPClient, IdStack, IdUDPServer, IdSocketHandle;
type
  TUDPMainForm = class(TForm)
    SourceGroupBox: TGroupBox;
    HostNameLabel: TLabel;
    HostAddressLabel: TLabel;
    HostName: TLabel;
    HostAddress: TLabel;
    UDPServer: TIdUDPServer;
    UDPAntiFreeze: TIdAntiFreeze;
    PortLabel: TLabel;
    Port: TLabel;
    BufferSizeLabel: TLabel;
    BufferSize: TLabel;
    UDPMemo: TMemo;
    procedure FormCreate(Sender: TObject);
    procedure UDPServerUDPRead(Sender: TObject; AData: TStream; ABinding: TIdSocketHandle);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  UDPMainForm: TUDPMainForm;implementationconst
  HOSTNAMELENGTH = 80;{$R *.DFM}procedure TUDPMainForm.FormCreate(Sender: TObject);
begin
  HostName.Caption := UDPServer.LocalName;
  HostAddress.Caption := GStack.LocalAddress;
  Port.Caption := IntToStr(UDPServer.DefaultPort);
  BufferSize.Caption := IntToStr(UDPServer.BufferSize);
  UDPServer.Active := True;
end;procedure TUDPMainForm.UDPServerUDPRead(Sender: TObject; AData: TStream; ABinding: TIdSocketHandle);
var
  DataStringStream: TStringStream;
  s: String;
begin
  DataStringStream := TStringStream.Create('');
  try
    DataStringStream.CopyFrom(AData, AData.Size);
    UDPMemo.Lines.Add('Received "' + DataStringStream.DataString + '" from ' + ABinding.PeerIP + ' on port ' + IntToStr(ABinding.PeerPort));
    s := 'Replied from ' + UDPServer.LocalName + ' to "' + DataStringStream.DataString + '"';
    ABinding.SendTo(ABinding.PeerIP, ABinding.PeerPort, s[1], Length(s));
  finally
    DataStringStream.Free;
  end;
end;
end.