Check If Application Already Open

Author: admin | Category: Form, Tips and Tricks

//This is delphi example how to Check If Application Already Open
//Create new application then leave the Unit1 as what is it
//Show the units with Ctrl+F12 then choose Project1 Unit
//Use this code then compile your application
//Now your application won't run twice or more
 
program Project1;
 
uses
  Forms,
  Unit1 in 'Unit1.pas' {Form1},
  Windows;
 
{$R *.res}
 
//begin
//  Application.Initialize;
//  Application.CreateForm(TForm1, Form1);
//  Application.Run;
//end.
 
var
appMutex:THandle;
begin
  appMutex := CreateMutex(nil,true,'MUTEX');
  if GetLastError <> ERROR_ALREADY_EXISTS then
  begin
    Application.Initialize;
    Application.Title := 'MUTEX';
    Application.CreateForm(TForm1, Form1);
    Application.Run;
  end;
end.

Tags: Application, Form