客户端

procedure TfrmClient.btnSaveClick(Sender: TObject);var    cmd:String; //服务器通信命令    ASize,TotalSize:Int64;//缓冲区大小,文件流大小    AFileStream:TFileStream;//文件流变量begin    IdTCPClient1.Host:=Edit1.Text;    IdTCPClient1.Port:=StrToIntDef(Edit2.Text,9225);    IdTCPClient1.Connect;    Try      IdTCPClient1.IOHandler.WriteLn('BEGIN');//提示客户端开始接收      cmd:=IdTCPClient1.IoHandler.ReadLn;      //以'|'分离文件名      dlgSave.FileName:=Copy(cmd,Pos('|',cmd)+1,Length(cmd));      if not dlgSave.Execute then      begin          IdTCPClient1.IOHandler.WriteLn('CANCEL');//告诉服务器取消          IdTCPClient1.Disconnect;          Exit;      end;      //分离文件大小      TotalSize:=StrToInt(Copy(cmd,0,Pos('|',cmd)-1));      //建立文件流准备接收      AFileStream:=TFileStream.Create(dlgSave.FileName,fmCreate);      try //开始循环接受          Repeat              IdTCPClient1.IOHandler.Writeln(IntToStr(AFileStream.Size));//发送当前传输的位置              ASize:=Min(TotalSize-AFileStream.Size,IdTCPClient1.IOHandler.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.IOHandler.ReadStream(AFileStream,ASize);//接收流              StatusBar1.Panels[1].Text:=Format('当前传输位置%d/大小%d',[AFileStream.Size,TotalSize]);              Application.ProcessMessages;          Until AFileStream.Size=TotalSize;  //当大小一致时退出循环      finally          AFileStream.Free;//释放文件流      end;      IdTCPClient1.IOHandler.WriteLn('END');//告诉服务器已经接收完毕      StatusBar1.Panels[1].Text:='传输文件成功';    except          StatusBar1.Panels[1].Text:= '连接服务器失败或者对方已经中断传输！';    End;    IdTCPClient1.Disconnect;              //断开连接 end;

服务端

unit PasServer;interfaceuses  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,  Dialogs, IdContext, IdBaseComponent, IdComponent, IdCustomTCPServer,  IdTCPServer, StdCtrls, ComCtrls,Math;type  TfrmServer = class(TForm)    Label1: TLabel;    Edit1: TEdit;    btnStart: TButton;    btnExit: TButton;    btnOpen: TButton;    IdTCPServer1: TIdTCPServer;    OpenDialog1: TOpenDialog;    Label2: TLabel;    Edit2: TEdit;    Label3: TLabel;    Edit3: TEdit;    StatusBar1: TStatusBar;    ProgressBar1: TProgressBar;    btnCancel: TButton;    procedure btnOpenClick(Sender: TObject);    procedure btnExitClick(Sender: TObject);    procedure btnStartClick(Sender: TObject);    procedure IdTCPServer1Connect(AContext: TIdContext);    procedure IdTCPServer1Execute(AContext: TIdContext);    procedure FormCreate(Sender: TObject);    procedure btnCancelClick(Sender: TObject);  private    { Private declarations }    AFileStream:TFileStream;    procedure ButtonBegin;    procedure ButtonEnd;  public    { Public declarations }  end;var  frmServer: TfrmServer;implementation{$R *.dfm}procedure TfrmServer.ButtonBegin;begin //VCL开始状态设置    btnStart.Enabled:=False;    btnExit.Enabled:=False;    btnCancel.Enabled:=True;    btnOpen.Enabled:=False;end;procedure TfrmServer.ButtonEnd;begin //VCL结束状态设置    btnStart.Enabled:=True;    btnExit.Enabled:=True;    btnCancel.Enabled:=False;    btnOpen.Enabled:=True;end;procedure TfrmServer.btnStartClick(Sender: TObject);begin    if not FileExists(Edit1.Text) then  //检测文件是否存在    begin        ShowMessage('文件不存在,请重新选择!!!');        exit;    end;    //建立文件流    AFileStream:=TFileStream.Create(Edit1.Text,fmOpenRead);    ProgressBar1.Max:=AFileStream.Size;    ProgressBar1.Position:=0;    ButtonBegin;//VCL开始状态设置    //服务器准备好连接    IdTCPServer1.DefaultPort:=StrToIntDef(Edit2.Text,9225);    if not IdTCPServer1.Active then IdTCPServer1.Active:=True;end;procedure TfrmServer.btnCancelClick(Sender: TObject);begin    StatusBar1.Panels[1].Text:='传输取消.....';    AFileStream.Free;  //释放文件流    ButtonEnd;   //VCL结束状态设置end;procedure TfrmServer.btnExitClick(Sender: TObject);begin    if IdTCPServer1.Active then        IdTCPServer1.Active:=False;    Close;end;procedure TfrmServer.btnOpenClick(Sender: TObject);begin    OpenDialog1.Execute;    if OpenDialog1.FileName<>'' then    begin        Edit1.Text:=OpenDialog1.FileName;        btnStart.Enabled:=True;    end;end;procedure TfrmServer.FormCreate(Sender: TObject);begin    StatusBar1.Panels[1].Text:='文件传输服务器V1.1';    btnStart.Enabled:=False;    btnCancel.Enabled:=False;end;procedure TfrmServer.IdTCPServer1Connect(AContext: TIdContext);begin      Edit3.Text:=AContext.Binding.IP;end;procedure TfrmServer.IdTCPServer1Execute(AContext: TIdContext);var    cmd:string;       //客户端命令信息    ASize:Integer;    //需要的传输流大小begin    with AContext.Connection do  //已经连街上的一个进程    begin        cmd:=UpperCase(IoHandler.ReadLn); //客户端发送的命令字符串        if cmd='BEGIN' then //开始传输....        begin            //告诉客户机文件大小及文件名            IoHandler.WriteLn(Format('%d|%s',[AFileStream.Size,ExtractFileName(Edit1.Text)]));            StatusBar1.Panels[1].Text:='准备传输......';            exit;        end;        if cmd='CANCEL' then //中止传输        begin            StatusBar1.Panels[1].Text:='客户中止传输....';            //保持传输状态            Exit;        end;        if cmd='END' then        begin            //文件传输完毕            btnCancel.Click;            StatusBar1.Panels[1].Text:='文件传输已经完成...';            Exit;        end;        //按照指定位置传输文件        AFileStream.Seek(StrToInt(cmd),soFromBeginning);//转到文件的传输位置        ASize:=Min(AFileStream.Size-AFileStream.Position,IoHandler.RecvBufferSize);        //计算需要发送大小，Min()函数在Math单元        //IoHandler.WriteBufferOpen;//准备发送缓冲        IoHandler.Write(AFileStream,Asize);        //IoHandler.WriteBufferClose;        StatusBar1.Panels[1].Text:=Format('当前文件传输位置%s/大小%d',[cmd,AFileStream.Size]);        ProgressBar1.Position:=ProgressBar1.Position+ASize;    end;end;end.