Delphi P2P文件傳輸程序客戶端代碼

今天我們介紹用Delphi寫一個簡單的P2P文件傳輸，一方發送文件，一方接受，直到傳輸完整個文件。本文主要介紹客戶端部分的實現，客戶端的運行效果如圖所示：

網絡文件傳輸程序客戶端完整代碼：

vIEw source print? 01 unit U_ClIEnt; 02 interface 03 uses 04   Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms, 05   Dialogs, IDBaseComponent, IdComponent, IdTCPConnection, IdTCPClIEnt, Math, 06   StdCtrls, ComCtrls; 07 type 08   Tfrm_ClIEnt = class(TForm) 09     SaveDialog1: TSaveDialog; 10     IdTCPClient1: TIdTCPClIEnt; 11     Button1: TButton; 12     StatusBar1: TStatusBar; 13     Edit1: TEdit; 14     Label1: TLabel; 15     Edit2: TEdit; 16     Label2: TLabel; 17     procedure Button1Click(Sender: TObject); 18   private 19     { Private declarations } 20   public 21     { Public declarations } 22   end; 23 var 24   frm_Client: Tfrm_ClIEnt; 25 implementation 26 {$R *.dfm} 27 procedure Tfrm_ClIEnt.Button1Click(Sender: TObject); 28 var 29   cmd: string; 30   ASize, TotalSize: Int64; 31   AFileStream: TFileStream; 32 begin 33   IdTCPClIEnt1.Host := Edit1.Text; //連接主機 34   IdTCPClIEnt1.Port := StrToIntDef(Edit2.Text, 9925); //端口 35   IdTCPClIEnt1.Connect; //連接 36   try 37     IdTCPClIEnt1.WriteLn('BEGIN'); //提示服務器開始接收 38     cmd := IdTCPClIEnt1.ReadLn; 39     //以“|”符號分離文件名 40     SaveDialog1.FileName := Copy(cmd, Pos('|', cmd) + 1, Length(cmd)); 41     if not SaveDialog1.Execute then 42     begin 43       IdTCPClIEnt1.WriteLn('CANCEL'); //告訴服務器取消 44       IdTCPClIEnt1.Disconnect; //斷開連接 45       exit; 46     end; 47     TotalSize := StrToInt(Copy(cmd, 0, Pos('|', cmd) - 1)); //分離文件大小 48     //建立文件流准備接收 49     AFileStream := TFileStream.Create(SaveDialog1.FileName, fmCreate); 50     try //循環開始接受 51       repeat 52         IdTCPClIEnt1.WriteLn(IntToStr(AFileStream.Size));//發送當前傳輸的位置 53         ASize := Min(TotalSize - AFileStream.Size, IdTCPClIEnt1.RecvBufferSize); 54         //選擇剩余大小和緩沖區大小小的一個作為傳輸的大小 55         IdTCPClIEnt1.ReadStream(AFileStream, ASize); //接收流 56         StatusBar1.SimpleText := Format('當前傳輸位置%d/大小%d', [AFileStream.Size, TotalSize]); 57         Application.ProcessMessages; 58       until AFileStream.Size = TotalSize; //大小一致了表示結束 59     finally 60       AFileStream.Free; //釋放文件流 61     end; 62     IdTCPClIEnt1.WriteLn('END'); //提示服務器傳輸完成 63     StatusBar1.SimpleText := '傳輸完成...'; 64   except 65     StatusBar1.SimpleText := '連接服務器失敗或者對方已經中斷傳輸！'; 66   end; 67   IdTCPClIEnt1.Disconnect; 68 end; 69 end.