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send receive TMemorystream over UDP

Posted on 2008-10-21
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Last Modified: 2013-11-23
hi all,

i trying like to porting my software that was compiled by delphi 6 to delphi 2007;
unfortunately, i can't found the subtitute for nmUDP (netmaster) component which have methode :
readstream, and sendstream  of Tmemorystream.
 
would you like to write some example code(methode) for sender and listener:
1. using UDP
2. send a TMEmorystream
3. the listener (aSocket or whatever) can receive data as a Tmemorystream or processed to be TMemory stream.

4.  whatever the component(indy, ics, synapse, etc...) used as long it's work on delphi 2007, it's ok

thanks
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Comment
Question by:pete_03
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8 Comments
 
LVL 17

Expert Comment

by:TheRealLoki
ID: 22771800
with Indy you'd use SendBuffer(Buffer, count) and Read(Buffer, count_)

here's a very simple example I wrote using a TStringStream...
using a TMemoryStream is similar, but a stringstream is easier to demonstrate

procedure TForm1.eSendKeyPress(Sender: TObject; var Key: Char);

var

  s: string;

  Buffer: Array [0..maxBufferSize] of Byte;

  count: Integer;

  stream: TStringStream;

begin

  if ord(Key) = vk_Return then

  begin

    Key := #0;

// now send this
 

    s := eSend.Text;
 

    IdUDPClient1.Host := 'localhost';

    IdUDPClient1.Port := StrToIntDef(eClientPort.Text, 1234);
 

    stream := TStringStream.Create(S);
 

    stream.Seek(0, soFromBeginning);

    stream.Read(Buffer, Stream.Size);

    IdUDPClient1.SendBuffer(Buffer, stream.size);
 

// you can also use the methof below

// or of course you can just use IdUDPClient1.Send(AData: string)

{

    s := eSend.Text;

    count := length(s);

    move(s[1], Buffer, count);

    IdUDPClient1.Host := 'localhost';

    IdUDPClient1.Port := StrToIntDef(eClientPort.Text, 1234);

    IdUDPClient1.SendBuffer(Buffer, count);

}

  end;

end;

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Author Comment

by:pete_03
ID: 22772131
thanks for reply, i am beginner of delphi, could wrap that code to a methode like:
procedure sendstream(aMemoryStream: TMemorystream) as easy as : nmUDP1.sendstream(myMemorystream)

and how about the listener ?
0
 
LVL 17

Expert Comment

by:TheRealLoki
ID: 22772713
show me your exact example of what you ant (i.e. your nmUDP code)
and I will show you how to do the equivalent in Indy.
The bit I need to understand is if you need to send the "size" of the stream first, or if you do not need the size
0
 

Author Comment

by:pete_03
ID: 22772762
procedure TMainModule.SendRecordValue(FRemoteHost: String; FPort: Integer);
var FMemoryStream: TMemoryStream;
    i : Byte;
    FValue : Single;
begin
   FMemoryStream := TMemoryStream.Create;
   try;
      for i := 0 to (record.Count-1) do
      begin
        FValue := record.Value[i];
        FMemoryStream.Write(FValue, SizeOf(FValue));
      end;

      NMUDP1.RemoteHost := FRemoteHost;
      NMUDP1.RemotePort := FPort;
      NMUDP1.SendStream(FMemoryStream);

   finally
      FMemoryStream.Free;
   end;
end;






procedure TfrmMonitoring.NMUDP1DataReceived(Sender: TComponent;
  NumberBytes: Integer; FromIP: String; Port: Integer);
var
    FMemoryStream : TMemoryStream;
    FValue : Single;
    I : Integer;
begin
   if NumberBytes > 0 then
   begin
      FByteReceived := FByteReceived + NumberBytes;
      FMemoryStream := TMemoryStream.Create;
      try
         NMUDP1.ReadStream(FMemoryStream);
         FMemoryStream.Position := 0;
         i := 0;
         repeat
            FMemoryStream.Read(FValue, SizeOf(FValue));
            ClientRecord.Value[i] := FValue;
            Inc(i);
         until (FMemoryStream.Position >= FMemoryStream.Size);
      finally
         FMemoryStream.Free;
      end;
   end;

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LVL 37

Expert Comment

by:Geert Gruwez
ID: 22773907
I mostly use a TStringList to send strings ...

you may need to check if ClientRecord.RecordCount works

procedure TForm1.SendRecordValue(aRemoteHost: String; aPort: Integer);

var i : Byte;

    List: TStringList;

begin

  List := TStringList.Create;

  try

    for i := 0 to (record.Count-1) do

      List.Add(Record.Value[i]);

    IdUDPClient1.Send(aRemoteHost, aPort, List.Text);

  finally

    List.Free;

  end;

end;
 

procedure TForm1.IdUDPServer1UDPRead(Sender: TObject; AData: TStream;

  ABinding: TIdSocketHandle);

var

  I : Integer;

  List: TStringList;

  Stream: TStringStream;

begin

  ClientRecord.RecordCount := 0;

  if AData.Size > 0 then

  begin

    List := TStringList.Create;

    try

      Stream := TStringStream.Create('');

      try

        Stream.CopyFrom(AData, AData.Size);

        List.Text := Stream.DataString;

      finally

        Stream.Free;

      end;

      ClientRecord.RecordCount := List.Count;

      for I := 0 to List.Count - 1 do

        ClientRecord.Value[i] := List[I];

    finally

      List.Free;

    end;

  end;

end;

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Author Comment

by:pete_03
ID: 22775029
on idUDP server, i doubleclick at onUDPRead Event then on editor:
procedure TForm1.IdUDPServer1UDPRead(Sender: TObject; AData: TBytes;
  ABinding: TIdSocketHandle);


procedure TForm1.IdUDPServer1UDPRead(Sender: TObject; AData: TStream;
  ABinding: TIdSocketHandle);

it's raises error, the parameters AData should be Tbytes instead TStream.
then i forced to change the parameters type to TStream as you suggest, application compiled successfully, i set a breakpoint  at this event, nothing fired when the client has sent a udp packet?


i am using indy10, D2007 default packages
0
 
LVL 37

Expert Comment

by:Geert Gruwez
ID: 22775544
oops, that was for Delphi 7

this is for Delphi 2007
procedure TForm1.IdUDPServer1UDPRead(Sender: TObject; AData: TBytes; ABinding: TIdSocketHandle);

var

  I : Integer;

  List: TStringList;

  Stream: TStringStream;

begin

  //ClientRecord.RecordCount := 0;

  if Length(AData) > 0 then

  begin

    List := TStringList.Create;

    try

      Stream := TStringStream.Create('');

      try

        Stream.Read(AData, Length(AData));

        List.Text :=  Stream.DataString;

        ClientRecord.RecordCount := List.Count;

        for I := 0 to List.Count - 1 do

          ClientRecord.Value[i] := List[I];

      finally

        Stream.Free;

      end;

    finally

      List.Free;

    end;

  end;

end;
 

procedure TForm1.SendRecordValue(aRemoteHost: String; aPort: Integer);

var i : Byte;

    List: TStringList;

begin

  List := TStringList.Create;

  try

    for i := 0 to (record.Count-1) do

      List.Add(Record.Value[i]);

    IdUDPClient1.Host := aRemoteHost;

    IdUDPClient1.Port := aPort;

    IdUDPClient1.Send(List.Text);

  finally

    List.Free;

  end;

end;

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LVL 17

Accepted Solution

by:
TheRealLoki earned 125 total points
ID: 22801368
ok, that's all pretty easy
as requested, using your code, I have just added the few things you need

procedure UDPSendStream(UDP_: TIdUDPClient; stream: TStream);

const

  maxBufferSize = 8192; // just make sure this is bigger than you ever need...you can loop but dont know if you need that in your situation

var

  Buffer: Array [0..maxBufferSize] of Byte;

  count: Integer;

begin

  stream.Seek(0, soFromBeginning);

  stream.Read(Buffer, Stream.Size);

  UDP_.SendBuffer(Buffer, stream.size);

end;
 
 

var FMemoryStream: TMemoryStream;

    i : Byte;

    FValue : Single;

begin

   FMemoryStream := TMemoryStream.Create;

   try

      for i := 0 to (record_.Count-1) do

      begin

        FValue := record_.Value[i];

        FMemoryStream.Write(FValue, SizeOf(FValue));

      end;
 

      IdUDPClient1.Host := FRemoteHost;

      IdUDPClient1.Port := FPort;

      UDPSendStream(IdUDPClient1, FMemoryStream);

   finally

      FMemoryStream.Free;

   end;

end;
 
 

procedure TForm1.IdUDPServer2UDPRead(Sender: TObject; AData: TStream; ABinding: TIdSocketHandle);

var

    FMemoryStream : TMemoryStream;

    FValue : Single;

    I : Integer;

begin

   if NumberBytes > 0 then

   begin

      FByteReceived := FByteReceived + NumberBytes;

      FMemoryStream := TMemoryStream.Create;

      try

         FMemoryStream.CopyFrom(AData, AData.Size);

         FMemoryStream.Position := 0;

         i := 0;

         repeat

            FMemoryStream.Read(FValue, SizeOf(FValue));

            ClientRecord.Value[i] := FValue;

            Inc(i);

         until (FMemoryStream.Position >= FMemoryStream.Size);

      finally

         FMemoryStream.Free;

      end;

   end;

end;

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