Delphi的Indy通訊中發送流檔案的注意事項

用戶端發送流到伺服器端有幾種方式，這裡討論兩種：

1.用戶端串連到伺服器後，發送一個流，伺服器接收一個流。

 

{*------------------------------------------------------------------------------
  用戶端發送流,假定已經建立串連
------------------------------------------------------------------------------*}
procedure TClientForm.Button3Click(Sender: TObject);
var s: string; stream: TStream;
begin

  try
    s := 'Hello world!';
    stream := TStringStream.Create(s);
    IdTCPClient1.OpenWriteBuffer;
    IdTCPClient1.WriteInteger(stream.Size);//注意這裡：要先寫入流的長度，在讀取的時候如果使用 AThread.Connection.ReadStream(stream);
    IdTCPClient1.WriteStream(stream, true);
  finally
    IdTCPClient1.CloseWriteBuffer;
    stream.Free;
  end;
end;

{*------------------------------------------------------------------------------
伺服器接收流
------------------------------------------------------------------------------*}
procedure TServerForm.IdTCPServer1Execute(AThread: TIdPeerThread);
var stream: Tstream;
begin

  if not AThread.Terminated and AThread.Connection.Connected then
  begin
    stream := TStringStream.Create('');

    AThread.Connection.ReadStream(stream);//這句相當於ReadStream(stream，-1，false)，就是根據流的前四個位元組讀出流長度，然後再將流讀出
    stream.Position := 0;
    Memo1.Lines.LoadFromStream(stream);

  end;

end;

2.用戶端串連到伺服器後，發送一個或多個流，當斷開的時候，伺服器將所有流合并在一起接收。

{*------------------------------------------------------------------------------
  用戶端發送流,假定還未建立串連
------------------------------------------------------------------------------*}

procedure TClientForm.Button3Click(Sender: TObject);
var s: string; stream: TStream;
begin
  IdTCPClient1.Connect;
  try
    s := 'Hello world!';
    stream := TStringStream.Create(s);
    IdTCPClient1.OpenWriteBuffer;
    IdTCPClient1.WriteStream(stream, true);
  finally
    IdTCPClient1.CloseWriteBuffer;
    stream.Free;
    IdTCPClient1.Disconnect;
  end;
end;

{*------------------------------------------------------------------------------
伺服器接收流
------------------------------------------------------------------------------*}
procedure TServerForm.IdTCPServer1Execute(AThread: TIdPeerThread);
var stream: Tstream;
begin

  if not AThread.Terminated and AThread.Connection.Connected then
  begin
    stream := TStringStream.Create('');

    AThread.Connection.ReadStream(stream,-1,true);//當中斷連線時候接收流
    stream.Position := 0;
    Memo1.Lines.LoadFromStream(stream);

  end;

end;