MFC menu item doesn't open dialog box - c++

I am having a proglem with the MFC application and the DialogBox. I am quiet sure I've done everything well with this tutorial: https://msdn.microsoft.com/en-us/library/6wb9s9ah.aspx
but still it doesn't work...
1. I've created new project with simple menu commands.
2. I've created new menu item (+ID) and new resource DialogBox (+ID).
3. Then I've added a new class named CParameters with the Class Wizard. For the BaseClass I've typed in CDialog.
4. I've created new handler on the menu item and added the code
CParameters dlg;
dlg.DoModal();
I think this is it, and this should work... But it doesnt... What is missing??
Here is my project, you can access it freely:
https://www.dropbox.com/sh/e6ajoxqk76hkuvn/AACRMY8bgcuyXguFwP240QB9a?dl=0
Additionally I want to insert TextEditors and to change parameters in my program from the dialog box.

A scan of your source code reveals that you are trying to handle the menu item event within the class that is going to display the dialog.
void CParameters::OnParam()
{
// TODO: Add your command handler code here
CParameters dlg;
dlg.DoModal();
}
I don't see anywhere else that you actually instantiate the dialog class (I may have missed it). What you are trying is incorrect. You cannot handle the menu item event within the same class that displays the dialog because that class (CParameters) has not been instantiated, so, it cannot respond to the menu event. Typically, the menu event would be handled in the mainframe class.

If you are doing this by adding a new menu item from a simple SDI application, then trying adding that part of code in
CMainFrame::OnEdit
OnEdit method used here is obtained from the Event Handler for the new menu item and Message type being COMMAND.

Related

C++ MFC Button on a second Dialog does nothing

I created a C++ MFC Program with the Visual Studio Wizard. There I set the application type to "Dialog Based".
I have a button on the first dialog, which opens another dialog. I created this second dialog by right clicking on the project -> Add -> Resource -> Dialog -> New.
Then I added a MFC class to the new dialog by double clicking it in resource view.
On the second Dialog I also created a button. I double clicked the button and added some code which should be executed.
When I run the program and click the button on the second dialog, nothing happens and the code is not executed. I did everything like with the button on the first dialog. That one works fine. Why is the second button not working and what do I need to do?
First Dialog
void CMFCApplication1Dlg::OnBnClickedButton1()
{
CDialogEx secondDialog(IDD_DIALOG1);
secondDialog.DoModal();
}
Second Dialog
void SettingsDlg::OnBnClickedButton1()
{
MessageBox(L"Button clicked", L"Button clicked", MB_OK);
}
#andrew-truckle, your side node was the answer! I changed it to:
void CMFCApplication1Dlg::OnBnClickedButton1()
{
SettingsDlg settingsDialog;
settingsDialog.DoModal();
}
Now the button works just as expected. Thank you very much!
Further Info (from #andrew-truckle)
For the benefit of others the issue here was that the original code declared the dialog like this:
CDialogEx secondDialog(IDD_DIALOG1);
That was wrong because the dialog was actually associated with the class SettingsDlg. This is the class that had the message map and event handlers etc. CDialogEx was the base class.
I added this update to the answer to save the reader from locating my comment to the question.

MFC: Emdedded child dialog is not showing up within parent dialog

I came across a tutorial showing how to embed a child dialog within a parent dialog using MFC. I am using Visual Studio 2015. My setup is as follows. Using the Visual Studio MFC Application Wizard to create a new MFC Visual C++ Project called MFCApplication3, I select a Dialog based application where MFC is used in a Shared DLL. Using boilerplate code, I have a simple Thick Frame Dialog, no maximize or minimize box.
In my resource view, I go to my Dialog editor to edit the main dialog. I add a picture control with a blank area in the center and name it IDC_STATIC. This will simply be used as a placeholder for my child dialog that I wish to embed. It looks like:
Still in the resource view, I create a new Dialog. I call it IDD_CHILD. I add some components. It looks like this:
Now back in the Solution Explorer, I add a class using the Add Class wizard, selecting to add an MFC Class. The class name is CChildDialog, with a base class of CDialog, and I use the already generated IDD_CHILD as the Dialog ID. It generates the .cpp and associated .h file. In the constructor of CChildDialog, I add a call to the Create function so the constructor becomes:
CChildDialog::CChildDialog(CWnd* pParent /*=NULL*/)
: CDialog(IDD_CHILD, pParent)
{
Create(IDD_CHILD, pParent);
}
Now I modify the dialog code generated automatically when I created the project. In CMFCApplication3Dlg.h, I add a private member of type CChildDialog* called m_childDlg, and #include the associated header file. In CMFCApplication3Dlg.cpp, I add this to the OnInitDialog function prior to the return statement:
CRect rc;
GetDlgItem(IDC_STATIC)->GetWindowRect(rc);
ScreenToClient(&rc);
m_childDlg = new CChildDialog(this);
m_childDlg->MoveWindow(rc);
Now I build the solution, run it, but it looks like it does in the first picture. A blank placeholder spot for a child dialog, but no child dialog. What could I be doing wrong?
It turns out (while composing this question) that the answer to my problem was two properties I need to set while in the resource view. When I have the child dialog open (IDD_CHILD), within the properties pane, I need to set the following properties:
Style: Child
Visible: TRUE
(I am not sure why Visible defaults to FALSE in this case). Making those two changes, voila! I get my embedded dialog:

C++ MFC create new dialog and add Combobox item

I'm using MFC to build an application with two dialogs.
When I press a button in the parent dialog a new window including a Combobox should apprear.
I created a first dialog with a button "New". This button will open the second dialog.
Therefor I created a second dialog with a Combobox. The Combobox has a linked variable variableCombobox. The second class is called CSecond.
Before I do anything in the new dialog I want to add an item to the Combobox.
In the first dialog class I create the new window like this:
void CFirstDlg::OnBnClickedNew()
{
CSecond dlg2 = new CSecond();
dlg2.variableCombobox.AddString(L"test");
dlg2.DoModal();
}
The program crashes in the line I want to add the test string to the Combobox showing an assertion error.
I noticed that the dlg2 object is null but I don't know why.
Can anyone tell me how to create a second window immediately adding an new item in the Combobox of the second window?
The problem is the second dialog is a modal dialog. The windows does not exist before the call to DoModal() and no longer exist after that function returns. Therefore calling AddString on the combobox is not all right, since the combo box does not exist at that time.
The solution is to initialize the dialog with your desired values (like in the constructor for instance, or other methods) and then in OnInitDialog() use those values to setup the controls (including this call to AddString for the combobox).

MFC Menu Item not properly invoking a modal dialog

I've created a simple Dialog box with a few controls (edit, text, etc) and saved
it to the resource folder in GME/GME.rc/Dialog
I added an auto-gen'd event handler which created a new class (Class.cpp
for the purposes of this example) Note: the Class::Class(CWnd *pParent) :
CDialogEx(Class::IDD, pParent) constructor is empty, I'm not sure if that's
relevant but I don't think it is..
There's a MESSAGE_MAP COMMAND(menu_item_id, &class::member_function())
invocation within the Class.cpp was auto-generated. It's wrapped in the
standard BEGIN_MESSAGE_MAP macro stuff.
However: when the menu item is clicked, the item remains gray. The
properties for "enabled=true" and "gray=false" are both properly
configured. So, I assume this is error is due to the message handler isnt
registered.
Any help would be appreciated.
Without code, it's pretty darn hard to help. Are you sure you put the message handler for the menu id in either a CView, CFrame, CDocument, or CWinApp derived class? If you put the menu handler in your dialog class, it's not going to do you much good.
Dialogs do not contain the code to run through the list of ON_UPDATE_COMMAND_UI handlers that MFC uses to enable menu items. Ordinarily this is handled by CFrameWnd for example. Try calling UpdateDialogControls in your OnInitDialog function.
I see that your code is also missing the ON_UPDATE_COMMAND_UI macro for the menu item, even though the handler it would reference was created for you.
You add menu item handlers to the window that has the menu, which is usually the CMainFrame. Copy the message map and handler to the CMainFrame and see if that helps. I'm not sure what you're trying to do here - I assume you want to display 'Class' (maybe better to edit your post to call this 'ExampleDialog' or something...) when the menu item is clicked, right? Or did you somehow add a menu to your CDialogEx-derived class? If the last, I guess this is what Mark is referring to - 'how are you displaying the menu'? How are you manually adding a menu to your dialog?

Not able to Show a Dialog Box in its class using SW_SHOW in MFC?

I am trying to create a wizard like structure using dialog boxes...So I replaced the code in CDialog1App as below
CDialog1Dlg* dlg = new CDialog1Dlg;
m_pMainWnd = dlg;
dlg->Create(IDD_DIALOG1);
dlg->ShowWindow(SW_SHOW);
the above worked fine...its displying the dialog box.but I have added another dialog box...
So in the first dialog box if the user clicks Next it has to hide the first dialog box and display the second dialog..
//CDialog1 class
void CDialog1Dlg::OnBnClickedNext()
{
// TODO: Add your control notification handler code here
CDialog2* dialog2 = new CDialog2();
dialog2->Create(IDD_DIALOG2);
dialog2->ShowWindow(SW_SHOW);
this->ShowWindow(SW_HIDE);
}
in the above code am creating an object for the Dialog2 class and trying to show that....
Now the problem is,when I click next its hiding both the windows..What can I do..I tried several types but its still its not workin..Please dont suggest me to do with PropertySheet..It will work with that, i know ...but I want this using Dialog Box for some reason
You're creating the dialog2 with the default parent window (NULL):
dialog2->Create(IDD_DIALOG2);
But the default parent seems to be dialog1 in your case. And since you hide dialog1 which is the parent of dialog2, dialog2 is also hidden.
Find the window (CWnd) of either your main app dialog (if you have one visible apart from your wizard), or use the desktop window as the parent.
For example:
dialog2->Create(IDD_DIALOG2, GetDesktopWindow());