netunit.pas

用在局域网中完成机子之间的数据传递

unit NetUnit;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, StdCtrls, Mask, ToolEdit, ExtCtrls, Buttons, NMSTRM, Psock,
  ComCtrls, Menus, NMUDP, WinSock, ShellAPI;

Var
  MsgStream:TMemoryStream;
  LocalIP:String;
  LocalCName:String;
  BroadCastIP:String;

  procedure  IniMsgStream;
  function   GetLocalIP:String;
  procedure  SetBroadCastIp;
  function   GetLocalCName: string;

implementation

uses Main;

function GetLocalIP: 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);
try
    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;
finally
    WSACleanup;
end;
end;

procedure  IniMsgStream;
begin
  MsgStream.Position:=0;
  MsgStream.Size:=0;
end;

procedure SetBroadCastIp;
var
  i,j,iHead:Integer;
  sHead,s:String;
  ai:array [1..3] of integer;
begin
{1~126.255.255.255  (A类网广播地址）
128~191.XXX.255.255 (B类网广播地址）
192~254.XXX.XXX.255 (C类网广播地址）}
j:=1;
for i:=0 to Length(LocalIP) do
  begin
  if LocalIP[i]='.' then
    begin
    ai[j]:=i;
    Inc(j);
    end;
  if j>3 then break;
  end;
sHead:=Copy(LocalIP,1,ai[1]-1);
iHead:=StrToInt(sHead);
if iHead<128 then  //A类网
  begin
  BroadCastIP:=sHead+'.255.255.255';
  end
else
  begin
  if iHead<192 then //B类网
    begin
    s:=Copy(LocalIP,1,ai[2]-1);
    BroadCastIP:=s+'.255.255';
    end
  else  //C类网
    begin
    s:=Copy(LocalIP,1,ai[3]-1);
    BroadCastIP:=s+'.255';
    end;
  end;
end;

function GetLocalCName: string;
var
  CNameBuffer : PChar;
  fl_loaded : Boolean;
  CLen : ^DWord;
begin
  GetMem(CNameBuffer,255);
  New(CLen);
  CLen^:= 255;
  fl_loaded := GetComputerName(CNameBuffer,CLen^);
  if fl_loaded then
    GetLocalCName := StrPas(CNameBuffer)
  else
    GetLocalCName := '未知';
  FreeMem(CNameBuffer,255);
  Dispose(CLen);
end;


end.