Hi,

I'm starting development of a trading application in equities and Forex 
and I'm thinking of using .NET remoting.

The structure would be something like this:

A server for receiving quotes from exchanges and storing them in a 
database as well as populating a class designed to store the current 
prices.
I would like this server to be on a separate machine from the GUI as 
there will be more than one GUI needing the information.

I would like the server to push the information to the clients instead 
of them polling the server at a fixed interval so I was thinking of 
having an event on the server that sends the data to the clients.
The problem is that I've found no examples of using events through 
remoting in Delphi.

Can someone point me to some examples of how to do this?

thanks,
 nisbus

Ok I've started a sample project to test this, it consists of:

A package containing a class and an interface:

type
  [Serializable]
  TRemote = class
  private
    fRandomNumber : integer;
    procedure SetRandomNumber(const Value: integer);
  published
    property RandomNumber : integer read FRandomNumber write 
SetRandomNumber;
  public
    constructor create;
  end;

  IRemote = interface
    function GetNewNumber : integer;
    procedure TimerFire(State : TObject);
  end;

A unit declaring the interface:

type
  TRemoting = class(MarshalByRefObject,IRemote)
  private
    fRandomNumber : integer;
    procedure SetRandomNumber(const Value: integer);
  published
    property RandomNumber : integer read fRandomNumber write 
SetRandomNumber;
  public
    Time : System.Threading.Timer;
    function GetNewNumber : integer;
    procedure CreateData;
    procedure TimerFire(State : TObject);
    constructor Create;
  end;

implementation

{ TRemoting }

constructor TRemoting.Create;
begin
  inherited;
  Time := System.Threading.Timer.Create(TimerFire,nil,0,1000);
end;

procedure TRemoting.CreateData;
begin
  Randomize;
  RandomNumber := Random(100);
end;

function TRemoting.GetNewNumber: integer;
begin
  result := RandomNumber;
end;

procedure TRemoting.SetRandomNumber(const Value: integer);
begin
  fRandomNumber := Value;
end;

procedure TRemoting.TimerFire(State: TObject);
begin
  CreateData;
end;

and a GUI for retrieving the data:

type
  TForm1 = class(TForm)
    Label1: TLabel;
    procedure FormShow(Sender: TObject);
  private
    { Private declarations }
  public
    fChannel : TCPChannel;
    fRemote : IRemote;
    Remote : TRemote;
    State : TObject;
    procedure localFire(State:TObject);
  end;

var
  Form1: TForm1;

implementation

{$R *.nfm}

{ TForm1 }

procedure TForm1.FormShow(Sender: TObject);
begin
  fChannel := TCPChannel.Create;
  ChannelServices.RegisterChannel(fChannel);
  fRemote := 
Activator.GetObject(TypeOf(IRemote),'tcp://localhost:8099/Remoting.TCP') 
as IRemote;
  Include(fRemote.TimerFire,LocalFire);
end;

procedure TForm1.localFire(State: TObject);
begin
  label1.Text := Convert.ToString(fRemote.GetNewNumber);
end;

Now the server runs fine and the timer seems to create a new random 
number every second (I added a button to the GUI that called the 
GetNewNumber function of the remote object, which worked).

Now when I try to compile the GUI it complains on the   
Include(fRemote.TimerFire,LocalFire); with an E2035 Not enough actual 
parameters error.
I've used the include command before and then it needed only equivalent 
information so what is the problem?

thanks,
  nisbus



nisbus wrote:
> Hi,
>
> I'm starting development of a trading application in equities and 
> Forex and I'm thinking of using .NET remoting.
>
> The structure would be something like this:
>
> A server for receiving quotes from exchanges and storing them in a 
> database as well as populating a class designed to store the current 
> prices.
> I would like this server to be on a separate machine from the GUI as 
> there will be more than one GUI needing the information.
>
> I would like the server to push the information to the clients instead 
> of them polling the server at a fixed interval so I was thinking of 
> having an event on the server that sends the data to the clients.
> The problem is that I've found no examples of using events through 
> remoting in Delphi.
>
> Can someone point me to some examples of how to do this?
>
> thanks,
> nisbus