Send a message to a application

listening

sendmessage
 brb with example, want to beat other people to it!!!

What do you mean by message? If you mean windows message, then Craig's done that. If you mean message like "hello world" then a good place to look is the chat example in Delphi5\Demos\Internet\Chat

I think what you have in mind here is pipes - you need the Windows API functions *namedpipes -

CreateNamedPipe,
ConnectNamedPipe,
TransactNamedPipe

and the others.

If this isn't enough, I can write a small demo for you.

yes sburck name the pipes :)

bear in mind that you can't create named pipe servers on '95 or '98...

listening,

allright craig capel
so far so right, but how do I send a string to another application that i have written, and that application has then a event?

Hi,
compile these two apps and run to see a demo of sending and recieving messages :

unit SendMsgTimeoutSendU;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, ExtCtrls;

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure FormCreate(Sender: TObject);
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

{Whoops! This function is imported in the Delphi source code incorrectly; the
 return value should be BOOL, not LRESULT}
function SendMessageTimeout(hWnd: HWND; Msg: UINT; wParam: WPARAM;
  lParam: LPARAM; fuFlags, uTimeout: UINT; var lpdwResult: DWORD):BOOL; stdcall;

var
  Form1: TForm1;
  UserMessage: UINT;  // holds our user defined message identifier

implementation

{$R *.DFM}

{re-link the external function}
function SendMessageTimeout; external user32 name 'SendMessageTimeoutA';

procedure TForm1.FormCreate(Sender: TObject);
begin
  {register the user defined Windows messsage}
  UserMessage := RegisterWindowMessage('SendMessageTimout Test Message');
end;

procedure TForm1.Button1Click(Sender: TObject);
var
  MsgResult: DWORD;
begin
  {send the message, and time out after 300 milliseconds}
  SendMessageTimeout(HWND_TOPMOST, UserMessage, 0, 0,
                     SMTO_NORMAL, 300, MsgResult);

  {indicate that the SendMessageTimeout function has returned}
  ShowMessage('Returned');
end;

end.






unit SendMstTimeoutGetU;

interface

uses
  Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
  StdCtrls, ComCtrls;

type
  TForm1 = class(TForm)
    Label1: TLabel;
    ProgressBar1: TProgressBar;
    Label2: TLabel;
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }
    procedure DefaultHandler(var Msg); override;
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  UserMessage: UINT;  // holds our user defined message identifier

implementation

{$R *.DFM}

procedure TForm1.DefaultHandler(var Msg);
var
  iLoop: Integer;  // general loop counter
begin
  {process message normally}
  inherited DefaultHandler(Msg);

  {if this is our user defined message...}
  if TMessage(Msg).Msg=UserMessage then
  begin
    {...display some user interface objects}
    ProgressBar1.Visible := TRUE;
    Label2.Visible := TRUE;
    Form1.Repaint;

    {animate the progress bar for a short time}
    for iLoop := 0 to 100 do
    begin
      ProgressBar1.Position := iLoop;
      Sleep(10);
    end;

    {turn off the user interface objects}
    ProgressBar1.Visible := FALSE;
    Label2.Visible := FALSE;

    {indicate that the message was handled}
    TMessage(Msg).Result := 1;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  {register the user defined Windows message}
  UserMessage := RegisterWindowMessage('SendMessageTimout Test Message');
end;

end.

mmm...

Barry, i know how you feel, it happens to me all the time :)

;-)