ShellExecute , How I can Tell my project that the application is closed ?

Question

If I call ShellExecute from my delphi application,

how can I determine if that program that I called is done, so that I may return to my app and do some other stuff after that other program is done.

For Example, open notepad , after done and close it , show message in my application "Done!"

You are using the wrong function. Use CreateProcess and wait on the process handle. — David Heffernan, Apr 26 '16 at 17:37

score 1 · Answer 1 · answered Apr 26 '16 at 16:21

You need to use ShellExecuteEx with SEE_MASK_NOCLOSEPROCESS. Check this out and see my comments inline:

var
    sei: TShellExecuteInfo;
    exitCode: Cardinal;
begin
    ZeroMemory(@sei, SizeOf(sei));
    with sei do
    begin
        cbSize := SizeOf(sei);
        fMask := SEE_MASK_NOCLOSEPROCESS; // Tell ShellExecuteEx to keep the process handle open
        Wnd := WindowHandleIfNeeded; // Can be omitted
        lpVerb := 'open';
        lpFile := PChar(PathOfExeToRun);
        lpParameters := PChar(ParametersToUse);
        lpDirectory := PChar(WorkingDirectoryToUse); // Can be omitted
        nShow := SW_NORMAL; // Can be omitted
    end;

    if ShellExecuteEx(@sei) then
    begin
        // I have encapsulated the different ways in begin/end and commented.

        // *** EITHER: Wait for the child process to close, without processing messages (if you do it in a background thread)
        begin
            WaitForSingleObject(sei.hProcess, INFINITE);
        end;

        // *** OR: Wait for the child process to close, while processing messages (if you do it in the UI thread)
        begin
            while MsgWaitForMultipleObjects(1, sei.hProcess, FALSE, INFINITE, QS_ALLINPUT) = (WAIT_OBJECT_0 + 1) do begin
                Application.ProcessMessages
            end;
        end;

        // *** OR: Do something else, and in the middle you can check whether the child is still running using this:
        begin
            GetExitCodeProcess(sei.hProcess, exitCode);
            if exitCode == STILL_ACTIVE then begin
                // It's still running!
            end else begin
                // It has finished!
            end;
        end;

        // At the end, close the handle
        CloseHandle(sei.hProcess);
    end; 
end;

ShellExecute , How I can Tell my project that the application is closed ?

1 Answers1