i'd like to ask the user "Are you sure that you want to quit the application?" question. If the user presses Yes, the application will terminate. If the user the presses No, the application will continue running. How do i do that?
I use visual c++ 2008 and mfc.
You need to handle the WM_CLOSE message, which can do in MFC by adding ON_WM_CLOSE to your CMainFrame class's message map, and providing an implementation of the OnClose function.
(The Class Wizard can do this for you.)
void CMainFrame::OnClose()
{
if (AfxMessageBox("Exit application?", MB_YESNO) == IDYES)
__super::OnClose();
}
__super is an MSVC extension that allows you to refer to the most immediate base class. If you are compiling in another compiler (unlikely for an MFC app), or using non-standard extensions makes you uncomfortable, you can substitute the actual name of the base class.
The approach suggested by Marijke is correct. But for it to compile you must add ON_WM_CLOSE in the CMainFrame message map, and you must use the actual base class where Marijke used CFrameWnd. (There are several possible base classes.) For example, the message map could look like this if the base class is CMDIFrameWndEx:
BEGIN_MESSAGE_MAP(CMainFrame, CMDIFrameWndEx)
ON_WM_CREATE()
ON_WM_CLOSE()
....
Related
I am trying to set up a MFC C++ App in Visual Studio 2019 such that modifies the user's text as they are typing.
Current layout is 2 radio buttons,
ID= rdbOn (set to Group = True, with Value int variable m_isOn = 1)
ID= rdbOff, m_isOn value would be = 0
and 1 Edit Control,
ID= txtInputBox, with Value CString variable m_inputString
Currently, for testing I can see how it would work for a button on click, it would take something like the following and just SetDlgItemText of the result. But that would be after they have typed, not WHILE they are typing.
void Onsomebtnclick()
{
//convert CString to String of m_inputString
//do some string manipulation
//convert back to CString
//SetDlgItemText(txtInputBox, result)
}
Update:
got EN_CHANGE to work
I was able to get EN_CHANGE working with the flag suggestion from user #GoGoWorx. However, now I just have a slight problem that the cursor is back to the beginning of the edit control txtInput.
I'm reading about using a CEdit::SetSel but don't know how to use that directly in my code. I tried
CEdit control MFC, placing cursor to end of string after SetWindowText
someDlg::someFunction()
{
//some logic stuff to get a result string
SetDlgItemText(txtInputBox, result);
//need it to set the cursor to the end
//I tried these, but it didn't recognize (expression must have class type?)
//txtInputBox.SetSel(0, -1);
//txtInputBox.SetSel(-1);
}
It sounds like you need to use the ON_EN_CHANGE message-map notification (called after the control has been updated due to typing or pasting for example)
BEGIN_MESSAGE_MAP(CMyDialog, CDialog)
ON_EN_CHANGE(IDC_EDIT_CONTROL, &CMyDialog::OnEnChangeEditControl)
END_MESSAGE_MAP()
void CMyDialog::OnEnChangeEditControl()
{
// Copy or call your Onsomebtnclick() here
}
I'm not sure what you're using for the numeric identifier for the edit control, since these are typically upper case defines - replace IDC_EDIT_CONTROL above with your define (possibly txtInputBox, but again, these are normally upper case, so I'm not sure).
Also change CMyDialog for the name of your dialog class too.
Note that we're using the ON_EN_CHANGE message-map handler here instead of the ON_EN_UPDATE, since the ON_EN_CHANGE message is sent after the control has been updated, whereas ON_EN_UPDATE is called just before it's updated.
The message-map handlers are described in the Remarks section of the CEdit control documentation: https://learn.microsoft.com/en-us/cpp/mfc/reference/cedit-class?view=msvc-160
Regarding your concern about modifying things as the user types - this should be fine, since every change (keystroke or paste from clipboard, etc.) should trigger this handler to be called, where you can change whatever you need. Just be sure that when you're updating the control, you don't trigger the ON_EN_CHANGE again and end up in a recursive 'change' loop.
You might be able to do this with some sort of flag to indicate you're the one updating the control, as opposed to the user, however it's probably better to subclass the CEdit control to do what you're wanting. There are a few examples out there of how to do this (it's not as difficult as it might sound), for example:
https://www.codeproject.com/Articles/27376/Avoiding-EN-CHANGE-notifications
So, I am working on a class called DMFWriteExportData and trying to get it run in Batch.
I am at a point where I need to figure out a way to get rid of fieldControl and the reason being it does not let me Run the class on the server and throws an error because it is not supposed to be running on server? (not sure)
Error: "The method Dialog Control.control cannot be called from the server; use methods on the Dialog Field class instead."
-
public Object dialog()
{
DialogRunbase dialog = new DialogRunbase("#DMF372", this);
FormStringControl control;
dialogExecution = dialog.addFieldValue(extendedTypeStr(dMFExecutionId), executionId);
control = dialogExecution.fieldControl();
control.mandatory(true);
control.displayLength(24);
control.registerOverrideMethod(methodstr(FormStringControl, lookup), methodstr(DMFWriteExecutionParameters, executionIdLookup), this);
control.registerOverrideMethod(methodstr(FormStringControl, modified), methodstr(DMFWriteExecutionParameters, executionIdModified), this);
dialogdescription=dialog.addFieldValue(extendedTypeStr(description),DMFExecution::find(executionId).Description);
dialogdescription.enabled(false);
return dialog;
}
I am wondering:
If it is actually true that this class cannot be set to server
when using control.registerOverrideMethod
If yes, what would be the ideal solution to overcome this situation,
is there any way I can create custom lookups? I see there is method
called registerOverrideMethod in the DialogField class.
Any help would be appreciated.
Thanks,
Khosla
The reason why you cannot (and should) run the code above in batch is because it uses dialog controls that only exist on the client side. You should never run this kind of code on server. Please check runon property of your class and set it to called from.
However, I assume you are using RunBaseBatch. If you are on AX 2012, you should use the SysOperation framework instead.
When using RunBaseBatch, all code is on the same class. This way, you are mixing client side code (main method, dialog method etc) with the code that should run on server (run method). For this reason you should set the "runon" property of the class to CalledFrom, not Server.
You can solve this by using SysOperation which applies the Model View Controller (MVC) pattern that neatly sepperates the two.
For an introduction to SysOperation, check my blog here:
AX2012: SysOperation introduction
Using the MFCApplication wizard in Visual C++ 2012, if "Generate attributed database class" is checked, a header with some special syntax (attributed C++ classes) are generated, which look like this:
// MFCApplication2Set.h: interface of the CMFCApplication2Set class
//
#pragma once
// code generated on March-05-13, 9:26 AM
[
db_source(L"Provider=SQLNCLI11.1;..."),
db_table(L"dbo.tblEmployee")
]
class CMFCApplication2Set
{
public:
... big list of stuff that corresponds to the fields in your db table omitted ...
}
The above header corresponds to a mostly empty implementation file:
// MFCApplication2Set.cpp : implementation of the CMFCApplication2Set class
//
#include "stdafx.h"
#include "MFCApplication2.h"
#include "MFCApplication2Set.h"
#ifdef _DEBUG
#define new DEBUG_NEW
#endif
// CMFCApplication2Set implementation
That was the WHOLE implementation class. Notice that:
A. No parent class name is specified anywhere.
B. There's some "Visual C++ magic" going on here, that is, as a novice to modern C++, I'm lost.
db_source is documented here but the documentation is pretty thin or at least opaque to me.
Questions:
I was mystified by this syntax when I first saw it, but I figured out it's probably a variant of this Attributes feature in Visual C++. It is that, right?
How am I meant to I use these generated "attributed database class" objects? I found this documentation but if you look carefully at that documentation, that code sample is showing people the Old Way and the New Way, and is not telling me what I want to know which is how to use this new object that the IDE can not give me any documentation or code completion features for. Also since the generated code for the CMFCApplication2Set class generated by the wizard does not reference any types or class names, I'm lost. If I could even use some IDE feature to know what methods and stuff have been Magically Injected into this Magical mystery Object, I'd be better off. The only think I can think to do is to learn the old way and learn all the things you can call from the old two-separate-ATL-types world, and then somehow learn to combine them.
In a nutshell, I'm looking for the minimum syntax I need to know to actually use one of these Attributed Database Class instances, variables, as they are generated in a new MFC app by the wizard. The instance shown below is a member of an MFC document class and CMFCApplication2Set m_MFCApplication2Set is declared as a field inside the MFC document class.
What I have tried is to use this "untyped object". This object appears to have lots of data fields (m_X) and has only one method that shows up in IDE code completion, called GetRowSetProperties. Thanks to whatever magic or injection is going on, this generated Attributed Database Class (which does not visibly inherit anything) is a complete mystery to me at edit time and compile time.
Here's me just trying to inspect this thing to see if it even initialized itself when its constructor ran:
BOOL CMFCApplication2Doc::OnNewDocument() { if (!CDocument::OnNewDocument()) return FALSE;
TRACE( m_MFCApplication2Set.m_AStringFieldName); // outputs NOISE.
return TRUE; }
At compile time and edit time, the IDE gives me NO help about the types involved in this "anonymous" class that inherits from nothing, but which gets lots of secret powers due to some kind of Injection via those attributes I'm guessing. At debug time, I can see that there is more than just a bunch of data fields in this C++ class, but this still doesn't help me know how to use it. A minimal code sample of using one of these to go get a recordset from the database, would be great.
Update: Calling OpenDataSource is fun, because it compiles but the IDE doesn't think it should be valid. Nevertheless, it runs, and returns 0 as the result, but that doesn't actually initialize this CThingyThatVisualStudioGaveYouThatYouDontKnowWhatItIs:
This is a deprecated feature of attributed C++ code. Pre-processor expands code and replaces attributes with actual base classes. If you enable generation of these intermediate files, things are going to be more clear to you:
You will have XXX.mrg.cpp and XXX.mrg.h files generated, which you can review and see the real C++ code forwarded to compiler.
The attributes will be replaced with substituted bases classes, maps like BEGIN_COLUMN_MAP etc. The attributed source code is compact, but the feature is deprecated and looking into expanded code it should be easy (if necessary) to strip the attributes and copy expanded code right into source. It's easy with DB attributes, and more difficult with COM attributes since the internal dependencies are most sophisticated.
I notice Debug.Assert does not trigger in Metro apps, however, if the project is a traditional one like Console or WinForm, it does trigger. And yes, I am in Debug mode.
Is it a setting not properly set in Visual Studio (11 Beta)? Or Debug.Assert is intended to be disabled in metro apps?
I know many exceptions are swallowed during the execution of Metro apps, but Debug.Assert is so handy that I can't think of a reason why it should be disabled.
Seems like a bug. I would roll out my own assert method. Something like:
[Conditional("DEBUG")]
public static void Assert(bool condition)
{
if (!condition)
System.Diagnostics.Debugger.Break();
}
It does trigger, look in the Output window. It just doesn't automatically prompt you to ask if you want a debugger break and thus just keeps motoring.
The DefaultTraceListener.AssertUIEnabled property is false. That's an implementation problem, can't display a message box on top of Metro UI. Which does actually work but the monitor switches to the desktop, pretty undesirable when you would have liked to click No. Hard to solve and no doubt on the todo list. You can't easily get to the property to set it to true, it is inaccessible from the metadata. Filip's workaround sounds half-decent.
There is the same problem with F# in WinRT, in VS2013. The assert statement, which is an alias for System.Diagnostics.Debug.Assert, does not raise an exception, so unless you are watching the Output window then your assertions can fail without being noticed. Even if you are watching, it is hard to find the spot where the assertion was raised.
I followed Filip's suggestion and wrote a short utility, as follows:
namespace MyProj.Infrastructure
module Diagnostics =
let Assert condition = if not condition then
System.Diagnostics.Debugger.Break()
I chose Debugger.Break over raising an exception because it stops the debugger at the place the assertion fails. However, raising an exception is an acceptable alternative.
I didn't have any suitable global projects or modules already in my solution, so I had to create them just for this, which was quite annoying.
I have a method void abc(IAnimal animal). When I type in another method abc( how do I make ReSharper show a list of objects implementing IAnimal?
Thx
On my installation CTRL-ALT-B gives you a list of implementations of an interface.