udp文件传输（代码修改）

[wqvic]

传输端：unit UnitClient;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, StdCtrls, IdBaseComponent, IdComponent, IdUDPBase, IdUDPClient,
IdAntiFreezeBase, IdAntiFreeze, Gauges;


type
TFormClient = class(TForm)
Button1: TButton;
Edit1: TEdit;
OpenDialog1: TOpenDialog;
IdUDPClient1: TIdUDPClient;
Gauge1: TGauge;
Label1: TLabel;
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;

var
FormClient: TFormClient;

implementation

{$R *.dfm}

procedure TFormClient.Button1Click(Sender: TObject);
Var ReceivedString:String;
Mem:TFileStream;
P:Array[0..1023] of byte;
Posi,Len:Integer;
begin
if OpenDialog1.Execute then
begin
IdUDPClient1.Host:=Edit1.Text;
IdUDPClient1.Active:=True;
IdUDPClient1.Send('Send file:File Name:'+OpenDialog1.FileName);
ReceivedString:=IdUDPClient1.ReceiveString();
if UpperCase(ReceivedString)='RECIVED FILE NAME OK!' then
begin
Mem:=TFileStream.Create(OpenDialog1.FileName,fmOpenRead);
try
Posi:=0;
IdUDPClient1.Send('Send File:File Length:'+IntToStr(Mem.Size));
ReceivedString:=IdUDPClient1.ReceiveString();
if UpperCase(ReceivedString)='RECIVED FILE LENGTH OK!' then
begin
While Posi<Mem.Size do
begin
Len:=1024;
if Mem.Size-Posi<1024 then
Len:=Mem.Size-Posi;
Mem.Read(P,Len);
IdUDPClient1.SendBuffer(P,Len);
Inc(Posi,Len);
Gauge1.Progress:=Round(Posi/Mem.Size*100);
ReceivedString:=IdUDPClient1.ReceiveString();
if UpperCase(ReceivedString)<>'RECIVED FILE PACKAGE OK!' then
Break;
Application.ProcessMessages;
end;
IdUDPClient1.Send('Send File:File End!');
end else
ShowMessage('Send file cancel!');
finally
Mem.Free;
end;
end;
end;
end;

end.
接受端：
unit UnitServer;

interface

uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs,IdBaseComponent, IdComponent, IdUDPBase, IdUDPServer,IdSocketHandle,
IdAntiFreezeBase, IdAntiFreeze, Gauges,RpRave;

type
TServerForm = class(TForm)
IdUDPServer1: TIdUDPServer;
procedure IdUDPServer1UDPRead(Sender: TObject; AData: TStream;
ABinding: TIdSocketHandle);
procedure FormCreate(Sender: TObject);
procedure FormDestroy(Sender: TObject);
private
FileName:String;
FileSize:Integer;
Mem:TFileStream;
m:Tmemorystream;
{ Private declarations }
public
{ Public declarations }
end;

var
ServerForm: TServerForm;

implementation

{$R *.dfm}

procedure TServerForm.IdUDPServer1UDPRead(Sender: TObject; AData: TStream;
ABinding: TIdSocketHandle);
Var Str:String;
begin
AData.Seek(0,0);
SetLength(Str,AData.Size);
AData.Read(Str[1],AData.Size);
if Pos('Send file:File Name:',Str)>0 then
begin
Delete(Str,1,Length('Send file:File Name:'));
FileName:=Str;
Str:='Recived File Name OK!';
ABinding.SendTo(ABinding.PeerIP,ABinding.PeerPort,Str[1],Length(Str));
end else if Pos('Send File:File Length:',Str)>0 then
begin
Delete(Str,1,Length('Send File:File Length:'));
FileSize:=StrToIntDef(Str,0);
if not FileExists(FileName) then
Mem:=TFileStream.Create(FileName,fmOpenReadWrite or fmCreate)

else
Mem:=TFileStream.Create(FileName,fmOpenReadWrite);
Str:='Recived File Length OK!';
ABinding.SendTo(ABinding.PeerIP,ABinding.PeerPort,Str[1],Length(Str));
end else if Pos('Send File:File End!',Str)>0 then
begin
if Mem<>nil then
begin
Mem.Free;
Mem:=nil;
Str:='Recived File OK!';
ABinding.SendTo(ABinding.PeerIP, ABinding.PeerPort, Str[1], Length(Str));
end;
FileName:='';
FileSize:=0;
end else
begin
Mem.Seek(0,2);
AData.Seek(0,0);
Mem.CopyFrom(AData,AData.Size);
m:=Tmemorystream.Create;
m.copyFrom(Mem,Mem.size);
m.SavetoFile('f:\'+FileName);
Str:='Recived File Package OK!';
ABinding.SendTo(ABinding.PeerIP, ABinding.PeerPort, Str[1], Length(Str));
Application.ProcessMessages;
end;
end;

procedure TServerForm.FormCreate(Sender: TObject);
begin
IdUDPServer1.Active:=True;
FileName:='';
FileSize:=0;
Mem:=nil;
end;

procedure TServerForm.FormDestroy(Sender: TObject);
begin
if Mem<>nil then
Mem.Free;
end;

end.
无语法错误，但运行时，弹出ShowMessage('Send file cancel!');，我已确定是接受端有错误，大家帮忙改一下啊

[fox1999]

UDP 啊 UDP

嘻嘻

應該先實現一個 UDP 的可靠傳輸協議才，再做傳文件。

[hongqi162]

丢包处理，校验包...............

[laowang2]

up

[binghui123]

先检查下IP,端口吧

[happyct]

这样的代码，估计发送1M的文件都有可能失败。客户端一个while循环就不停调用IdUDPClient1.SendBuffer(P,Len); 怎么有这么轻松的事情啊。

最简单的校验方法：在IdUDPClient1.SendBuffer(P,Len); 后面sleep(1000)看看有没机会成功。

即使成功了，你的代码也是没任何用途的。