100分求一个用Idudpserver写的检测客户端是否在线的源码.

Question

求一个用Idudpserver写的检测客户端是否在线的源码[email protected]

Answer 1

一个form,一个udpserver,一个udpclient,一个listbox
最好在局域网内调试，如果只有一台机器，你就看先打开的程序，后打开的由于同ip登录的回应消息我屏蔽了,所以看不到
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unit Unit1;interfaceuses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, IdUDPClient, IdBaseComponent, IdComponent, IdUDPBase,
  IdUDPServer,IdSocketHandle;type
  TForm1 = class(TForm)
    server: TIdUDPServer;
    client: TIdUDPClient;
    ListBox1: TListBox;
    Button1: TButton;
    Button2: TButton;
    Edit1: TEdit;
    Label1: TLabel;
    procedure serverUDPRead(Sender: TObject; AData: TStream;
      ABinding: TIdSocketHandle);
    procedure Button1Click(Sender: TObject);
    procedure Button2Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;var
  Form1: TForm1;implementation
uses Winsock;
{$R *.dfm}
var Ip:string;
function LocalIP : string;
type
  TaPInAddr = array [0..10] of PInAddr;
  PaPInAddr = ^TaPInAddr;
var
  phe:PHostEnt;
  pptr:PaPInAddr;
  Buffer:array [0..63] of char;
  I:Integer;
  GInitData:TWSADATA;
begin
  WSAStartup($101, GInitData);
  Result := '';
  GetHostName(Buffer, SizeOf(Buffer));
  phe :=GetHostByName(buffer);
  if phe = nil then Exit;
  pptr := PaPInAddr(Phe^.h_addr_list);
  I := 0;
  while pptr^[I] <> nil do begin
  result:=StrPas(inet_ntoa(pptr^[I]^));
  Inc(I);
end;
  WSACleanup;
end;
function BroadAddr(addr:string):string;
var i:integer;
begin
  result:='';
  for i:=length(addr) downto 1 do
  begin
    if ord(addr[i])=46 then
    begin
      result:=copy(addr,1,i)+'255';
      exit;
    end;
  end;
end;
procedure TForm1.serverUDPRead(Sender: TObject; AData: TStream;
  ABinding: TIdSocketHandle);
var LogMessage:string;
    DataStringStream: TStringStream;
    s:string;
begin
  DataStringStream:=TStringStream.Create('');
  DataStringStream.CopyFrom(AData, AData.Size);
  s:=DataStringStream.DataString;
  if byte(s[1])=1 then
  begin
    LogMessage:=#2;
    Client.Send(Ip,8880,LogMessage);
    listbox1.Items.Add(abinding.PeerIP);
  end;
  if byte(s[1])=2 then
  begin
    if abinding.PeerIP=LocalIP then exit;
    listbox1.Items.Add(abinding.PeerIP);
  end;
  if byte(s[1])=0 then
  begin
    listbox1.Items.Delete(listbox1.Items.IndexOf(abinding.peerIP));
  end;
end;procedure TForm1.Button1Click(Sender: TObject);
var LogMessage:string;
    ip:string;
begin
  server.Active:=true;
  client.Active:=true;
  ip:=LocalIP;
  LogMessage:=#1;
  Client.Send(BroadAddr(ip),8880,LogMessage);end;procedure TForm1.Button2Click(Sender: TObject);
var LogMessage:string;
    ip:string;
begin
  ip:=LocalIP;
  LogMessage:=#0;
  Client.Send(BroadAddr(ip),8880,LogMessage);end;procedure TForm1.FormCreate(Sender: TObject);
var port:integer;
begin
  port:=strtoint(inputbox('输入端口号!','','8880'));
  client.Port:=port;
  server.DefaultPort:=port;
  client.Active:=true;
  server.Active:=true;
end;end.