|
Of course. 
It depends what you do... you need to debug it yourself
Greetings from Germany
|
|
|
|
|
|
Hi experts
I want to detect shutdown of the system through my application mine application is a property sheet.
Thanks in advance
RYK
|
|
|
|
|
VC_RYK wrote: I want to detect shutdown of the system through my application mine application is a property sheet.
Handle WM_QUERYENDSESSION.
Nibu thomas
Microsoft MVP for VC++
Code must be written to be read, not by the compiler, but by another human being.
Programming Blog: http:\\nibuthomas.wordpress.com
|
|
|
|
|
WM_ENDSESSION
prasann
who else
|
|
|
|
|
But i want any API suppose i ahve to use somewhere in console base aaplication.
|
|
|
|
|
VC_RYK wrote: suppose i ahve to use somewhere in console base aaplication.
In that case, you could use the SetConsoleCtrlHandler() API.
Mark
Mark Salsbery
Microsoft MVP - Visual C++
![Java | [Coffee]](https://codeproject.global.ssl.fastly.net/script/Forums/Images/coffee.gif)
|
|
|
|
|
I've written a control that hosts the web browser which works great when viewing a web page (HTML) but has a problem when viewing an XPS document. When the operator tabs to my host window I send a WM_SETFOCUS message which is processed by the following function:
VOID OnSetFocus(HWND hwnd)
{
IOleObject *pOleObject=getOleObject();
if (pOleObject)
{
RECT rc;
GetClientRect(hwnd,&rc);
pOleObject->DoVerb(OLEIVERB_UIACTIVATE,NULL,pSites,0,hwnd,&rc);
IWebBrowser2 *pWebBrowser=NULL;
if (pOleObject->QueryInterface(IID_IWebBrowser2,(void **)&pWebBrowser)==S_OK)
{
IOleInPlaceActiveObject *pOleInPlaceActiveObj=NULL;
if (pWebBrowser->QueryInterface(IID_IOleInPlaceActiveObject,(void **)&pOleInPlaceActiveObj)==S_OK)
{
MSG msg={0};
msg.hwnd=hwnd;
msg.lParam=1;
msg.wParam=VK_TAB;
msg.message=WM_KEYDOWN;
pOleInPlaceActiveObj->TranslateAccelerator(&msg);
pOleInPlaceActiveObj->Release();
}
pWebBrowser->Release();
}
}
}
The above works fine for web pages as focus always seems to be changed to the first window below 'Shell DocObject View' which for web pages is 'Internet Explorer_Server'. When using the XPS view plug-in there are two levels below which are 'DocObject_Top_Class' and 'HwndWrapper'.
The window layouts when viewing a web page looks like this:
MyHostWindow
ShellEmbedding
Shell DocObject View
Internet Explorer_Server --> This window gets the focus which means the tab key continues to function
The window layout when viewing an XPS document looks like this:
MyHostWindow
ShellEmbedding
Shell DocObject View
DocObject_Top_Class --> This window gets the focus which means the tab key stops working
HwndWrapper[WCP_Hosted... --> Focus should be here so the tab key continues to function
Does anyone know how to sort out the focus problem?
|
|
|
|
|
There is no source code available for the current location!
When my VS2005 run the vc++ project, it will appear above message.
But my VS2005 did not have this problem yeaterday.
How do I solve this problem?
|
|
|
|
|
Release build? 
Greetings from Germany
|
|
|
|
|
Hi,
Generally people use 'new' keyword to memory allocation. But I red that it will slow down the process or project. I also know that using virtual memory is one of solution to it. But the thing is, I am not getting how to implement this code in C++/MFC. Please help me to achieve this feat by providing any one of simple program.
Thanking you,
-Jagadeesh Musham
|
|
|
|
|
I will make a citation that I read somewhere (sorry, I don't remember from who it was):
"Early optimization is the root of all evil". Specially in your case if you don't know exactly what you are doing and you just heard that somewhere.
So, are you having troubles ? Is your program becoming slow ? Are you allocating/dealocating a lot (and when I say a lot, read it as really a LOT) of objects ?
If no, then you will probably make things a lot more complex and probably much buggy than they are. Because if you need to implement a system that manages memory allocation in a more efficient manner it's going to be quite complex.
Finally, I really would like to see where you read it and if you didn't interpret the thing out of context (or maybe the author is just plain stupid). C'mon you're not going to experience slowdown if you allocate a bunch of integers or objects.
|
|
|
|
|
Cedric Moonen wrote: I will make a citation that I read somewhere (sorry, I don't remember from who it was):
"Early optimization is the root of all evil".
Knuth: We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil." (Knuth, Donald. Structured Programming with go to Statements, ACM Journal Computing Surveys, Vol 6, No. 4, Dec. 1974. p.268.)
BTW, my favorite one on the topic is:
“More computing sins are committed in the name of efficiency (without necessarily achieving it) than for any other single reason - including blind stupidity.” - W.A. Wulf
|
|
|
|
|
Thanks. That's a nice one, I agree 
|
|
|
|
|
Virtual memory is just a technique of pretending to have more RAM than you physically have. It's not a memory allocation technique for C++ objects, etc.
The main thing that will speed things up for you is to not do more allocation than you need - or repeat yourself if you need to do slow things, like connect to databases, etc...
These sorts of ideas are massively dependent on the details of your application.
But write it one way, and do some actual meaurements, and then try caching, delayed allocation, and all sorts of fun & games. Measure, then find out the chances are you've shaved some unnoticable milliseconds off your time.
Iain.
|
|
|
|
|
new is just fine.
Write the program, make it work, then optimize this stuff later.
I'd buy a better memory manager if you're not happy with the default one. (look at SmartHeap)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~<br />
Peter Weyzen<br />
Staff Engineer<br />
<A HREF="http://www.soonr.com">SoonR Inc -- PC Power delivered to your phone</A>
|
|
|
|
|
I have stored monochrome pixel values of an image in a buffer of type int**. Now I would like to create a bitmap out of it to use BitBlt() function to display it. How do I create a bitmap out of raw pixel values.
|
|
|
|
|
CreateBitmap()
You may be right
I may be crazy
-- Billy Joel --
Within you lies the power for good - Use it!
|
|
|
|
|
You beat me to it - but I plugged your image viewer helper app!
Iain.
|
|
|
|
|
HBITMAP CreateBitmap(
int nWidth,
int nHeight,
UINT cPlanes,
UINT cBitsPerPel,
CONST VOID *lpvBits
);
Have a look at the CreateBitmap (shocking name, I know) command - you can specify a pointer to data which will make up the bitmap. There are some issues with it - you'll need the data to match the bits per pixel, etc.
Or CreateDIBitmap may be better for you.
You'll have to transform you data into a format those command will be happy with though - and how hard that is depends on how "friendly" your format is.
If you search codeproject by author for PJ Arends, you can use his Image Viewer article to help you. It's great if you're fiddling about with DCs, and Bitmaps - it's saved hours of development for me in the past.
Iain.
|
|
|
|
|
I create an abstract class and a class derived from it. I know that an abstract class's object cannot be created until all its pure virtual functions are redefined within their derived class. However, How about the constructor and destructor functions? As they are special class functions, they can not be redefined within their derived class.
class Abstract_base {
public:
virtual ~Abstract_base()=0;
virtual void interface1() const = 0;
virtual const char* mumber() const
{
return _mumble;
};
protected:
char *_mumble;
};
class Concrete_derived : public Abstract_base {
public:
Concrete_derived()
{
};
virtual void interface1() const {};
};
int main
{
Concrete_derived trouble;
return 0;
}
The code above has link eror.(error LNK2019)
If I change "virtual ~Abstract_base()=0;" to "virtual ~Abstract_base()=0; {}", the link error disappeared. Why shall we add "virtual" to the destructor function?
Can you give me some explanation?
many thanks
Tomorrow is another day!
|
|
|
|
|
You shouldn't put a =0 after your destructor. This means that the function is a pure virtual function: the function be implemented by all child classes. It is quite odd to put that on a destructor.
A destructor is always required (one is supplied by default if you don't write it yourself) so, you need to provide a body. Which you did by adding {}. This is just an empty body, but it is still a body.
If you don't provide a body for your destructor, you'll get a linker error.
|
|
|
|
|
Cedric Moonen wrote: It is quite odd to put that on a destructor.
What? It is exactly what any abstract base class should have. Did you ever read Effective C++ by Scott Meyers?
|
|
|
|
|
led mike wrote: Did you ever read Effective C++ by Scott Meyers?
Nope but I was planning to buy it soon 
led mike wrote: It is exactly what any abstract base class should have.
Yes, I see. I never done it that way: I always used at least one pure virtual function.
|
|
|
|
|
richardye wrote: Can you give me some explanation?
You must provide a definition of the pure virtual destructor.
"Normal is getting dressed in clothes that you buy for work and driving through traffic in a car that you are still paying for, in order to get to the job you need to pay for the clothes and the car and the house you leave vacant all day so you can afford to live in it." - Ellen Goodman
"To have a respect for ourselves guides our morals; to have deference for others governs our manners." - Laurence Sterne
|
|
|
|
General 
News 
Suggestion 
Question 
Bug 
Answer 
Joke 
Praise 
Rant 
Admin 
Submit an article or tip
