unit transport;

interface

uses
  Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
  Dialogs, IdBaseComponent, IdComponent, IdTCPConnection, IdTCPClient,
  StdCtrls, ComCtrls, IdTCPServer;

type
  Ttrans = class(TForm)
    Edit2: TEdit;
    Edit3: TEdit;
    Button1: TButton;
    Label1: TLabel;
    Label2: TLabel;
    Button2: TButton;
    OpenDialog1: TOpenDialog;
    SaveDialog1: TSaveDialog;
    IdTCPClient1: TIdTCPClient;
    Edit1: TEdit;
    Button3: TButton;
    Button4: TButton;
    ProgressBar1: TProgressBar;
    IdTCPServer1: TIdTCPServer;
    StatusBar1: TStatusBar;
    procedure Button3Click(Sender: TObject);
    procedure Button4Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure IdTCPServer1Execute(AThread: TIdPeerThread);
  private
    AFileStream: TFileStream; //傳輸?shù)奈募?    procedure ButtonBegin;
    procedure ButtonEnd;
    { Private declarations }
  public
    { Public declarations }
  end;

var
  trans: Ttrans;

implementation

uses csMain;
{$R *.dfm}

procedure Ttrans.Button3Click(Sender: TObject);
begin
  if OpenDialog1.Execute then
    Edit1.Text := OpenDialog1.FileName;
end;

procedure Ttrans.Button4Click(Sender: TObject);
begin
  StatusBar1.SimpleText := '傳輸取消...';
  AFileStream.Free; //釋放文件流
  ButtonEnd; //VCL結(jié)束狀態(tài)設(shè)置
  close;
end;

procedure Ttrans.Button1Click(Sender: TObject);
begin
  if not FileExists(Edit1.Text) then //檢測(cè)文件是否存在
  begin
    Showmessage('文件不存在，請(qǐng)選擇文件！');
    exit;
  end;
  //建立文件流
  AFileStream := TFileStream.Create(Edit1.Text, fmOpenRead);
  ProgressBar1.Max := AFileStream.Size;
  ProgressBar1.Position := 0;
  ButtonBegin; //VCL開始狀態(tài)設(shè)置
  //服務(wù)器準(zhǔn)備好連接
  IdTCPServer1.DefaultPort := StrToIntDef(Edit3.Text, 9925);
  if not IdTCPServer1.Active then IdTCPServer1.Active := True;
end;

procedure Ttrans.ButtonBegin;
begin //VCL開始狀態(tài)設(shè)置
  Button1.Enabled := False;
  Button2.Enabled := False;
  Button3.Enabled := True;
  Button4.Enabled := False;
end;

procedure Ttrans.ButtonEnd;
begin //VCL結(jié)束狀態(tài)設(shè)置
  Button1.Enabled := True;
  Button2.Enabled := True;
  Button3.Enabled := False;
  Button4.Enabled := True;
end;

procedure Ttrans.IdTCPServer1Execute(AThread: TIdPeerThread);
var
  cmd: string; //接收到客戶端的字符串信息
  ASize: Integer; //需要傳輸?shù)牧鞔笮?begin
  with AThread.Connection do //已經(jīng)連街上的一個(gè)進(jìn)程
  begin
    cmd := UpperCase(ReadLn); //客戶端發(fā)送的命令字符串
    if cmd = 'BEGIN' then //開始傳輸
    begin
      //告訴遠(yuǎn)程傳輸文件的大小和文件名
      WriteLn(Format('%d|%s', [AFileStream.Size, ExtractFileName(Edit1.Text)]));
      StatusBar1.SimpleText := '準(zhǔn)備傳輸...';
      Exit;
    end;
    if cmd = 'END' then
    begin //傳輸完成
      Button3.Click;
      StatusBar1.SimpleText := '傳輸完成...';
      Exit;
    end;
    if cmd = 'CANCEL' then
    begin //傳輸取消
      StatusBar1.SimpleText := '傳輸取消...';
      //保持傳輸狀態(tài)
      Exit;
    end;
    //按照指定位置傳輸文件
    AFileStream.Seek(StrToInT(cmd), soFromBeginning); //轉(zhuǎn)到文件流傳輸?shù)奈恢?    if (AFileStream.Size - AFileStream.Position) >= RecvBufferSize then
      ASize := RecvBufferSize
    else ASize := AFileStream.Size - AFileStream.Position;
    //計(jì)算需要發(fā)送的大小，Min()函數(shù)在Math單元
    OpenWriteBuffer; //準(zhǔn)備發(fā)送緩沖
    WriteStream(AFileStream, false, false, ASize);
    //注意這個(gè)函數(shù)的參數(shù)。
    CloseWriteBuffer; //結(jié)束發(fā)送緩沖
    StatusBar1.SimpleText := Format('當(dāng)前傳輸位置%s/大小%d', [cmd, AFileStream.Size]);
    ProgressBar1.Position := ProgressBar1.Position + ASize;
  end;
end;

end.