Delphi的Indy通信中发送流文件的注意事项

客户端发送流到服务器端有几种方式，这里讨论两种：

1.客户端连接到服务器后，发送一个流，服务器接收一个流。

{*------------------------------------------------------------------------------

客户端发送流,假定已经建立连接

------------------------------------------------------------------------------*}

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);//注意这里：要先写入流的长度，在读取的时候如果使用 AThread.Connection.ReadStream(stream);

IdTCPClient1.WriteStream(stream, true);

finally

IdTCPClient1.CloseWriteBuffer;

stream.Free;

end;

end;

{*------------------------------------------------------------------------------

服务器接收流

------------------------------------------------------------------------------*}

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);//这句相当于ReadStream(stream，-1，false)，就是根据流的前四个字节读出流长度，然后再将流读出

stream.Position := 0;

Memo1.Lines.LoadFromStream(stream);

end;

end;

2.客户端连接到服务器后，发送一个或多个流，当断开的时候，服务器将所有流合并在一起接收。

{*------------------------------------------------------------------------------

客户端发送流,假定还未建立连接

------------------------------------------------------------------------------*}

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;

{*------------------------------------------------------------------------------

服务器接收流

------------------------------------------------------------------------------*}

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);//当断开连接时候接收流

stream.Position := 0;

Memo1.Lines.LoadFromStream(stream);

end;

end;