Question

I have some code that starts a process and hooks up an event handler to handle when the process exits, the code I have is written in C# and I wonder if something similar is possible with Delphi.

System.Diagnostics.Process myProcess = new System.Diagnostics.Process();
myProcess.StartInfo.FileName = "notepad.exe";
myProcess.EnableRaisingEvents = true;
myProcess.Exited += new System.EventHandler(Process_OnExit);
myProcess.Start();

public void Process_OnExit(object sender, EventArgs e)
{
    //Do something when the process ends
}

I don’t know much about Delphi so any help would be appreciated, thanks.

Answer 1

Yes, you can do something similar with Delphi. I have not seen using an event handler, but you can create a process, wait for it to finish, and then do something when that happens. Put it in another thread if you want to do something in the meantime.

Here is some code for creating a process and waiting that I scraped off the net:

procedure ExecNewProcess(const ProgramName : String; Wait: Boolean);
var
  StartInfo : TStartupInfo;
  ProcInfo : TProcessInformation;
  CreateOK : Boolean;
begin
  { fill with known state } 
  FillChar(StartInfo, SizeOf(TStartupInfo), 0);
  FillChar(ProcInfo, SizeOf(TProcessInformation), 0);
  StartInfo.cb := SizeOf(TStartupInfo);
  CreateOK := CreateProcess(nil, PChar(ProgramName), nil, nil, False,
              CREATE_NEW_PROCESS_GROUP or NORMAL_PRIORITY_CLASS,
              nil, nil, StartInfo, ProcInfo);
   { check to see if successful } 
  if CreateOK then
    begin
      //Note: This will wait forever if the process never ends! 
      // You are better off using a loop with a timeout, or WaitForMultipleObject 
      if Wait then
        WaitForSingleObject(ProcInfo.hProcess, INFINITE);
    end
  else
    begin
      RaiseLastOSError;
      //SysErrorMessage(GetLastError());
    end;

  CloseHandle(ProcInfo.hProcess);
  CloseHandle(ProcInfo.hThread);
end;