CODEWITHSUNDEEP
c++c++buildervcl
RisaAudr
RisaAudr

Reputation: 53

c++ with vcl: closing secondary form does not end process

I'm still learning c++ with vcl forms so forgive me if what I'm asking turns out to be simpler than it seems. For reference, I'm using c++ builder 10.1 berlin in a Windows environment.

I have a program with two forms (lets call them "MainForm" and "BackupForm"). I am accepting user input in MainForm, then when the user clicks a particular button ("DoSomething") that action sets a few variables then calls BackupForm->Show(); then MainForm->Hide(); to switch over to the second form which does more things.

The issue I'm having is this: if a user clicks the "X" in the upper right that normally closes a program, it only closes the BackupForm and does not end the process. If I did the same action on the MainForm it ends the process.

I looked around and either wasn't asking the right question or no-one but me has this issue, or perhaps hiding/showing to switch forms isn't the right way to go about it, but my overall question is this:

TLDR: Is there a way/method/etc. to detect the "close window" button being pressed on a secondary form and subsequently close the application, ending it's process without having to kill it in task manager?

If there's a better way to be switching forms that I'm unaware of, I wouldn't mind suggestions towards that end as well.

Also, if needed, I can post more of the code but I wasn't sure what would actually be helpful. Below is some of what I have:

Main (Function? Application?) Pre-generated by my IDE:

#include <vcl.h>
#pragma hdrstop
#include <tchar.h>
//------------------------------------------------------------------------
USEFORM("BackupFormCode.cpp", BackupForm);
USEFORM("UserBackupProgram.cpp", MainForm);
//----------------------------------------------------------------------
int WINAPI _tWinMain(HINSTANCE, HINSTANCE, LPTSTR, int)
{
    try
    {
        Application->Initialize();
        Application->MainFormOnTaskBar = true;
        Application->CreateForm(__classid(TMainForm), &MainForm);
        Application->CreateForm(__classid(TBackupForm), &BackupForm);
        Application->Run();
    }
    catch (Exception &exception)
    {
        Application->ShowException(&exception);
    }
    catch (...)
    {
        try
        {
            throw Exception("");
        }
        catch (Exception &exception)
        {
            Application->ShowException(&exception);
        }
    }
    return 0;
}

Button "DoSomething" Pressed in "MainForm":

void __fastcall TMainForm::ExecuteCopyClick(TObject *Sender)
{
    //Setting variables.... 
    //Then:
    BackupForm->Show();
    MainForm->Hide(); 
}

Upvotes: 1

Views: 3772

Answers (2)

Remy Lebeau
Remy Lebeau

Reputation: 598134

Your MainForm is being auto-created first, so it gets set as the Application->MainForm.

When the Application->MainForm is actually closed, it calls Application->Terminate(), causing Application->Run() to exit, thus allowing WinMain() to exit and the process to terminate.

When you show BackupForm, you are merely hiding the MainForm, not closing it. So Application->Terminate() is not getting called.

If you want the process to terminate when BackupForm is closed, you need to either:

  • Close() the Application->MainForm:

    void __fastcall TBackupForm::FormClose(TObject *Sender, TCloseAction &Action)
{
    Application->MainForm->Close(); 
}

    Or:

    void __fastcall TMainForm::ExecuteCopyClick(TObject *Sender)
{
    //Setting variables.... 
    //Then:
    Hide(); 
    BackupForm->ShowModal();
    Close();
}

  • just call Application->Terminate() directly:

    void __fastcall TBackupForm::FormClose(TObject *Sender, TCloseAction &Action)
{
    Application->Terminate(); 
}

Upvotes: 2

S. Petrić
S. Petrić

Reputation: 90

It's normal behavior. Both forms are auto-created, so closing the second form will not terminate the application...main form is still alive. You can solve this in several ways. Here is the quick one:

Show second form as modal:

void __fastcall TMainForm::ExecuteCopyClick(TObject *Sender)
      {
      this->Hide();
      BackupForm->ShowModal();
      this->Show();
      }

Now, the BackupForm has "full control" because it's shown as modal form. After BackupForm is closed, you can either show again your main form (as in example above), or close the main form.

Upvotes: 0

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