关于indy10：使用Delphi Indy 10进行UDP文件传输

UDP File Transfer Using Delphi Indy 10

我正在使用 Delphi Xe-3 indy 10 进行 udp 文件传输。我以小块的形式传递文件，在传输更大的文件和文本文件以外的文件时遇到问题。

在客户端调试时文件的大小保存错误，我无法找出原因。下面是客户端和服务器代码，客户端发送文件到服务器。
(我使用 udp 是因为我正在研究 Reliable udp。)

客户端代码(发送函数)中提到了问题。

服务器：

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procedure TForm2.serverUDPRead(AThread: TIdUDPListenerThread;
AData: array of Byte; ABinding: TIdSocketHandle);
var

str , len :string;
size : word;
index : word;

begin

setlength(b,length(Adata));
move(Adata[0],b[0],length(Adata)); // convert array of byte to tidbytes

index:=0;
setlength(Ext,b[index]); // get filename length
setlength(File_data , b[index+1]); // get file length
index:= index+2;
move(b[index],Ext[1],length(Ext)*2); // copy filename
index:= index+length(Ext)*2;
move(b[index],File_data[0],length(File_data)); // copy file

save.Visible:= true;
//progressbar1.Visible:= true;
progressbar1.Position
memo1.Lines.Add(‘Receving file…->’);

end;

procedure TForm2.SaveClick(Sender: TObject);
var
buttonSelected : Integer;
content:integer;
begin

savedialog1.FileName := Ext; // save file name
if savedialog1.Execute then // save dialog opens
try
if FileExists(SaveDialog1.FileName) then
begin
if MessageDlg(‘Do you want to overwrite the existing file ?’,
TMsgDlgType.mtConfirmation,mbYesNo,0) = IDNO then
begin
exit;
end
end;

Strm:=TFileStream.Create(Ext,fmCreate);
Strm.Position:=0;
//progressbar1.Value:= 100*length(File_data)/content; // set position to start
WriteTIdBytesToStream (Strm,File_data,length(File_data),0); // write bytes data to stream
memo1.Lines.Add(‘File transmission complete…’);
finally
strm.Free;
save.Visible := false;
progressbar1.Visible := false;
end;

end;

客户：

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procedure TForm1.LoadClick(Sender: TObject);
begin

//openDialog1.InitialDir := GetCurrentDir;

if openDialog1.Execute then

begin
Edit1.Text := OpenDialog1.FileName;
memo1.Lines.Add (Opendialog1.FileName);

Filename := ExtractFileName (Opendialog1.FileName);
Mem := TFileStream.Create(OpenDialog1.FileName,fmOpenRead); //connects the client

end;

{finally
opendialog1.Free;
end;
}

end;

procedure TForm1.SendClick(Sender: TObject);
var
size : word;
index : word;
begin
index := 0;
try
Posi:=0;
While Posi<Mem.Size do
begin
Len:=1024;
if Mem.Size–Posi<1024 then
begin
Len:=Mem.Size–Posi;
end;
setlength(chunk,len);
ReadTIdBytesFromStream(Mem,chunk,Len);

size := length(chunk) + length(Filename)*2 + 2; // it gets right sizes here ,
//chunk size is also correct
setlength(File_data,Size);
File_data[index] := length(Filename);
index:= index+1;
File_data[index]:= length(chunk);// its saved here ,value is reduced.
index:= index+1;
move(Filename[1],File_data[index],length(Filename)*2);
index:= index+length(Filename)*2;
move(chunk[0],file_data[index],length(chunk));

client.SendBuffer(‘127.0.0.1’,6002,File_data);
Inc(Posi,Len);
end;

finally
Mem.Free;
Edit1.Text:=”;
Filename:=”;
end;

end;

procedure TForm1.FormCreate(Sender: TObject);
begin
client.Bindings.Add.Port:= 0;
client.Active := true;
end;

end.

UDP File Transfer Using Delphi Indy 10

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