关于读写流的10个问题

Question

我试图在IdTCPServer和IdTCPClient之间交换数据，使用我在通过网络发送之前转换为流的集合。不幸的是，无论我如何尝试，我似乎都无法在客户端和服务器之间传递流。代码总是挂在IdTCPClient1.IOHandler上。ReadStream(myStream， -1, True) line。

我的代码的相关部分如下所示: 客户端

  with ClientDataModule do
  begin
    try
      try
        intStreamSize := StrToInt(IdTCPClient1.IOHandler.ReadLn); // Read stream size
        IdTCPClient1.IOHandler.ReadStream(myStream, -1, True);  // Read record stream
      finally
        ReadCollectionFromStream(TCustomer, myStream);
      end;
    except
      ShowMessage('Unable to read the record from stream');
    end;
  end;

服务器端

    try
      try
        SaveCollectionToStream(ACustomer, MStream);
      finally
        MStream.Seek(0, soFromBeginning);
        IOHandler.WriteLn(IntToStr(MStream.Size));   // Send stream size
        IOHandler.Write(MStream, 0);        // Send record stream
      end;
    except
      ShowMessage('Unable to save the record to stream');
    end;

如果你能帮助我解决这个问题，我将非常感激。

谢谢,

JDaniel

Answer 1

您正在将ReadStream()的AReadUntilDisconnect参数设置为True，这告诉它继续读取直到连接关闭。您需要将该参数设置为False。你还需要在AByteCount参数中传递流大小，因为你是单独发送流大小，所以你必须告诉ReadStream()实际读取多少。

试试这个:客户:

with ClientDataModule do
begin
  try
    intStreamSize := StrToInt(IdTCPClient1.IOHandler.ReadLn);
    IdTCPClient1.IOHandler.ReadStream(myStream, intStreamSize, False);
    myStream.Position := 0;
    ReadCollectionFromStream(TCustomer, myStream);
  except
    ShowMessage('Unable to read the record from stream');
  end;
end;

服务器:

try
  SaveCollectionToStream(ACustomer, MStream);
  MStream.Position := 0;
  IOHandler.WriteLn(IntToStr(MStream.Size));
  IOHandler.Write(MStream);
except
  ShowMessage('Unable to save the record to stream');
end;

如果你可以改变你的协议，那么你可以让Write()和ReadStream()在内部为你交换流大小，像这样:

客户:

with ClientDataModule do
begin
  try
    // set to True to receive a 64bit stream size
    // set to False to receive a 32bit stream stream
    IdTCPClient1.IOHandler.LargeStream := ...;
    IdTCPClient1.IOHandler.ReadStream(myStream, -1, True);
    myStream.Position := 0;
    ReadCollectionFromStream(TCustomer, myStream);
  except
    ShowMessage('Unable to read the record from stream');
  end;
end;

服务器:

try
  SaveCollectionToStream(ACustomer, MStream);
  MStream.Position := 0;
  // set to True to send a 64bit stream size
  // set to False to send a 32bit stream stream
  IOHandler.LargeStream := ...;
  IOHandler.Write(MStream, 0, True);
except
  ShowMessage('Unable to save the record to stream');
end;