I created main dialog and call no modal dialog, how can i check in main dialog that button is clicked in no modal?
For example if i call modal i can check like this:
Dialog Dlg;
int DlgResult = static_cast<int>(Dlg.DoModal());
if (DlgResult== IDOK)
{
//do smth.
}
If its a custom dialog, one way would be to use SendMessage() or PostMessage() to send the result to the main dialog when the non-modal dialog closes.
Even after the window closes, you will still have access to the C++ object representing the dialog. You can override OnOK and OnCancel and have them save a flag in the object.
Related
I'm a newcomer to MFC world. I need to have some dialog based operaion for an old application. There I'm having a trouble for an appraently obvious thing and that is I can't seem to find a way to close the child dialog (Modal) that I'm invoking from my parent (also a Modal). In all the ways I tried always both child and parent is getting closed at once.
Here is what I tried:
I've created a default MFC application in VS 2012 Professional
ParentDlg.cpp
void ParentDlg::OnBnClickedOk()
{
ChildDlg childDlg;
dialogOutput.DoModal();
CDialogEx::OnOK();
}
In my Child.cpp for a Close button (ID: IDCLOSE)
ChildDlg.cpp
void ChildDlg::OnBnClickedClose()
{
// TODO: Add your control notification handler code here
EndDialog(IDCLOSE);
}
But this is closing both the parent and child, but I need only the child dialog to be closed (Parent Dialog should remain open) as I'm clicking the 'Close' buton on the child dialog.
In short, I like to have the same behaviour of the default IDOK button of 'IDD_ABOUTBOX' dialog, which is also a Modal dialog and closes only the About Box when I click on the 'OK' button in it.
You should only place IDOK in the ID property of your close button. And only the child dialog will close. You should no longer create an event handler, and if you did, delete the event handler.
I am closing a modal dialog after I end a task, inside a separate thread from where I created a modal dialog:
void CmodguiApp::_notify_task_end() {
processingDialog->EndDialog(0);
}
This works fine if my application has focus (therefore the modal dialog has focus). But this causes the application to crash if I change window while the modal dialog is on (for instance, if I leave the application processing and switch to Firefox or so).
What could be wrong?
Do not end the dialog with EndDialog. Instead PostMessage with WM_CLOSE or WM_QUIT to the dialog window.
I have a custom dialog message box that pops-up when a edit control in my main dialog has wrong data.
CDlgError dlgError = new CDlgError(this);
dlgError.Create(CDlgError::IDD, this);
dlgError.m_staticMessage.SetWindowTextA("Error message!");
dlgError.ShowWindow(SW_SHOW);
//more code
I want the rest of the code to be executed only after i press an OK button in my CDlgError pop-up dialog. How can i do that?
Use DoModal instead of Create and ShowWindow to show your error dialog. e.g.
CDlgError dlgError = new CDlgError(this);
dlgError.m_strMessage = "Error message!";
dlgError.DoModal();
As you can see from the code you'll need to pass in the text and THEN set your message label inside CDlgError::OnInitDialog because the control won't be initialized before going modal.
You are creating a dialog using Create which shows a modalless dialog(you can click on other parts of application even dialog is open).
You requirement is for modal dialog where you can not click on any part of application until this dialog is closed.
To do this use DoModal function instead of create.
My program use a modeless dialog to interact with the user and also has a tray icon.
A user can quit the app immediately by using the tray icon.
BOOL OnInitDialog()
{
init data...
}
void OnDestroy()
{
destroy data...
}
void OnSomeButton()
{
CFileDialog dlg;
...
dlg.DoModal(m_hWnd));
access data...
...
}
void OnMenuExit()
{
DestroyWindow();
}
The problem is that when I popup a modal dialog(OnSomeButton), and then quit using the tray icon menu, the main dialog is destroyed first, and then the modal one returns, trying to access some invalid data, causing a crash.
I know i can add some check code before accessing the data, but is there any other way?
Is there any way to ensure OnSomeButton() returns before window destroy?
You need to add your own application level code. There is no system support for this issue primarily because there can be so many pecularities that no generic approach is possible.
Yeah. When you quit from the tray menu, you can send a WM_CLOSE or similar message to your modal dialog that causes it to exit. Even if your main window is destroyed before that OnSomeButton returns you will be okay provided the remainder of that function does not access any class internals (member variables etc). You could ensure this by having the window proc of your modal dialog return an 'abort' code or something when it is closed in this way.
I am developing a project using Qt4 and I have run into a slight issue.
I am creating a modal window from the main window. I want this to disable the toolbar at the top.
I have a menu item that spawns the modal from the menu. What I want is that when the modal is spawned that menus is disabled. I have tried using the setEnabled(false) function but that doesn't reset it.
Here is the code:
void Main_Screen::Create_ViPro()
{
std::auto_ptr<ViPro_Dialog> modal(new ViPro_Dialog(this));
modal->show();
modal->exec();
}
So It is just a simple class that is triggered when a menu item is selected. I feel that the problem stems from the fact that i'm setting the parent to the main screen, however I don't know how to create a modal without a parent(it doesn't make sense to do that). Is there a way to disable the parents toolbar from the child? The only thing I have seen so far is _fileMenu->setEnabled(false);
That works as long as I don't create the modal, but as soon as that is spawned, the menu works again. I'm totally lost.
Thanks in advance
Edit as Patrice
Here is the constructor
Main_Screen::Main_Screen(QWidget* parent /*= NULL*/)
: QMainWindow(parent),
_newProj(new QAction(tr("New &ViPro"), this)),
_fileMenu(menuBar()->addMenu(tr("&File")))
{
//create slot for creating a new project
connect(_newProj.get(), SIGNAL(triggered()), this, SLOT(Create_ViPro()));
_fileMenu->addAction(_newProj.get());
//if i do this then setEnabled(false) works perfectly and i can't access the menu
Create_ViPro()
}
So the function is signaled by triggering the newproject action. If i call the function directly from within the constructor it disables it as you stated patrice, however, if I have the function called via the trigger, it doesn't disable it. Am I handling the signal / slot mechanism wrong? Thanks again.
Another example, if I make the function create_vipro() as below
void Main_Screen::Create_ViPro()
{
_fileMenu->setEnabled(false);
}
The file menu isn't disabled when I trigger the event, so it must have nothing to do with the modal itself, but instead how signals are handled.
Since child is a modal dialog main screen can't react to event. But you can disable the toolbar (or menubar) before creating the modal dialog and enable it as soon as you leave the exec function:
void Main_Screen::Create_ViPro()
{
_fileMenu->setEnabled(false);
std::auto_ptr<ViPro_Dialog> modal(new ViPro_Dialog(this));
modal->show();
modal->exec(); // Will stay here until you close the modal dialog
_fileMenu->setEnabled(true);
}
if ViPro_Dialog is really a modal dialog it will works.
Another thing, since ViPro_Dialog is modal you can declare it locally without using auto_ptr:
void Main_Screen::Create_ViPro()
{
_fileMenu->setEnabled(false);
ViPro_Dialog modal(this);
modal.show();
modal.exec(); // Will stay here until you close the modal dialog
_fileMenu->setEnabled(true);
}
EDIT:
I guess (I can't test at work) that you can't enable/disable menu when it is executing a QAction. Signal is calling slots sequentially so QAction is busy when you try to disable the menu.
Try this:
In Main Screen, create a slot with one boolean parameter that enable/disable menubar. Just call the setEnabled function
In ViPro_Dialog, emit a signal with a boolean parameter (false at startup, true at validation)
In Create_ViPro, once dialog created, connect the new signal with the slot, exec dialog and don't forget to disconnect slot from signal:
void Main_Screen::Create_ViPro()
{
ViPro_Dialog modal(this);
// Connect signal/slot
modal.show();
modal.exec(); // Will stay here until you close the modal dialog
// Disconnect signal/slot
}
This can achieve what you want
EDIT2
You are doing a mistake when using modal dialog. There's a conflict between show() and exec(). When you are displaying modal dialog you don't need to disable other windows: it's automatically done by modal status of the dialog. There are many modal depth: http://qt-project.org/doc/qt-4.8/qt.html#WindowModality-enum. So your code should be:
void Main_Screen::Create_ViPro()
{
ViPro_Dialog modal(this);
// modal.setWindowModality(Qt::WindowModal); // Uncomment this line if you want to only disable parent
modal.exec();
}
Read this for more detail: http://qt-project.org/doc/qt-4.8/QDialog.html#details.
Using exec() doesn't just create a modal dialog, it also suspends most of the regular event handling, and only handles events in the dialog that is in exec(). This may include some UI updates (like the transitions from enabled to disabled), but I'm not positive. A better way to handle this might be to explicitly set the dialog modal, but allow the regular event loop to continue, something like this:
void Main_Screen::Create_ViPro()
{
ViPro_Dialog* modal = new ViPro_Dialog(this);
modal->setModal(true);
modal->show();
}
That code will still not visually disable the toolbar or menubar, but they should be unresponsive. To disable them, you could try combining this with Patrice Bernassola's answer.