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What happens if you alter this line:
hdcTempMem = CreateCompatibleDC(hdcMainMem);
to
hdcTempMem = CreateCompatibleDC(hdc); ?
Also - have you checked to see if the BitBlt operation is returning an error status or not?
Also - looking at the CreateCompatibleDC[^] documentation, it seems to me that you should be selecting a bitmap into hdcMainMem that you can draw on - otherwise (again, from what the documentation says) you only have a one pixel bitmap backing hdcMainMem. That seems to be backed up when I look at the double-buffering DC class documented here[^]. OK, it's for WTL, but it uses the standard GDI operations to implement the double-buffering.
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Thanks a lot for spotting my error. It was your last point about the one pixel bitmap that was the problem. I forgot to give hdcMainMem an area to draw on. Everything worked once I added:
blankImg = CreateCompatibleBitmap(hdc, screenRect.right, screenRect.bottom);
SelectObject(hdcMainMem, blankImg);
Now I can get back to work. I think thats a good thing?....
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your hdcMainMem needs a bitmap 
Greetings from Germany
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I want to use c language function localtime() for the conversion of seconds into date.
As I have learned from someone that this function used the date 1970-01-01 00:00:00 as the base to calculate seconds into date. But when I used it it seems that it use the base date as 1970-01-01 05:00:00. I can't understand this.
Also is it possible to calculate the date from seconds by using someother base date value. for example i have seconds starting from 1994-01-01 00:00:00 to now, then how to calculate the time from these seconds (base date + seconds).
The function used by me is as follows.
void Duration_to_time(int Seconds,char OutputTime[])
{
time_t count_second;
struct tm *newtime;
tzset();
count_second=Seconds;
newtime = localtime(&count_second);
if (strftime(OutputTime, 20, "%Y-%m-%d %H:%M:%S", newtime) == (size_t) 0)
printf("Could not get string from strftime()\n");
}
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Umer Aziz wrote: As I have learned from someone that this function used the date 1970-01-01 00:00:00 as the base to calculate seconds into date. But when I used it it seems that it use the base date as 1970-01-01 05:00:00. I can't understand this.
localtime adjusts the evaluated time to your local one (hence the five hours shift). use gmtime, instead.
Umer Aziz wrote: Also is it possible to calculate the date from seconds by using someother base date value. for example i have seconds starting from 1994-01-01 00:00:00 to now, then how to calculate the time from these seconds (base date + seconds).
To use 1994-01-01 00:00:00 as base date, simply add the corrensponding time_t value to your duration and then call gmtime and strftime)
If the Lord God Almighty had consulted me before embarking upon the Creation, I would have recommended something simpler.
-- Alfonso the Wise, 13th Century King of Castile.
This is going on my arrogant assumptions. You may have a superb reason why I'm completely wrong.
-- Iain Clarke
[My articles]
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Umer Aziz wrote: As I have learned from someone that this function used the date 1970-01-01 00:00:00 as the base to calculate seconds...
It actually goes back about 21600 seconds beyond that to 31-Dec-1969 @ 1800.
"Love people and use things, not love things and use people." - Unknown
"The brick walls are there for a reason...to stop the people who don't want it badly enough." - Randy Pausch
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Thanks a lot for your prompt response
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Hi,
I developing an application which stores the file paths and also i have a shell extension dll.i wanted to send a file path from a shell extension dll to an application through a registered windows message. is it possible.?
Jose Jo Martin
http://www.simpletools.co.in
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Check out WM_COPYDATA[^], it sounds like that is just what you need.
> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Life: great graphics, but the gameplay sux. <
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Sutter and Alexandrescu have a section on proper use of C++ exceptions that strongly encourages the use of C++ exceptions. I am confused by the last item, number 75, where they suggest avoiding exception specifications.
1) If you do not throw, then why bother trying to catch, which is what the previous items advocate?
2) If exception specifications are bad why does C++ support them?
Can someone please explain what I am missing?
Thanks
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Member 2603772 wrote: If you do not throw, then why bother trying to catch, which is what the previous items advocate?
Not using exception specifications doesn't mean you are guaranteeing that your code doesn't throw an exception - it's the reverse of that - you are making no guarantees about whether your code throws exceptions or not. If a piece of code you're calling has no exception specification, assume that it may throw *any* exception. Only handle exceptions if there's some action you can perform that fixes what caused the exception. Any other exception should be allowed to terminate the application - if you don't know how to fix what caused the exception, then you've got problems.
Member 2603772 wrote: If exception specifications are bad why does C++ support them?
They're not bad per se. The point is that C++ doesn't enforce them or (really) take any notice of them. That means that compilers won't verify that they're correct, so they're liable (like code comments) to become inaccurate as you change the code they describe, because you probably won't remember to change the exception specification.
This article[^] by Herb Sutter may help to make his view on exception specifications clearer?
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Maybe this article[^] helps you understand the exception specifications and why they are not a good idea.
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Dear All,
I just started to use MFC library together with Visual Studio 2008 to wrap around my
mathematical engine which I build as a console application.
I hope my question will be easy to answer. I have CListBox object which I fill time to time with error messages in catch block:
....
catch (std::exception& ex)
{
std::string str = ex.what();
m_List.AddString(str.c_str() );
}
....
Sometimes, error messages are longer then physical width of CListBox object and as a result truncated.
As far as I see, CListBox object does not have property in "Property list" to explicitly specify string/word wrapping. There are few properties such as "Multicolumn", "Horizontal Scroll", "Disable No Scroll" which does not help me to make it possible to view all length of error messages.
I am sure it must be easy way to do it. I hope someone will have some suggestions/comments about it issue.
Thank you in advance,
nuclph.
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nuclph wrote: I am sure it must be easy way to do it
The easy way is to use a different control. Think about it - what would it mean to word-wrap in a list - is the wrapped text the same or different items than the first bit of the line?
For what you're doing, I'd use a rich edit control, a) so I could specify a monospaced font like courier easily, and b) it's got this[^] useful method.
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Stuart is quite right - a multiline list control would be odd.
You could implement an owner draw one, and make each entry take two lines, with some sort of visual cue - but that would be hard work - and a waste if you commonly have a small amount of text for each entry.
Alternately, you could use a tooltip for your CListBox.
Read:
http://msdn.microsoft.com/en-us/magazine/dvdarchive/cc301416.aspx[^]
and then go to
http://www.dilascia.com/PixieDoc.htm#CListBoxTipHandler[^]
for code. All of Paul DiLascia's work is worth a look see. I learned loads from him when I started out.
Iain.
Codeproject MVP for C++, I can't believe it's for my lounge posts...
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Iain Clarke wrote: All of Paul DiLascia's work is worth a look see. I learned loads from him when I started out.
Indeed! I too learned truck loads from his articles. He died the night of September 3rd, 2008[^]. 
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Wow, that was news to me. I just assumed he'd made his piles from early microsoft shares (or from bribes to answer particular reader questions) and had retired to Tahiti.
As I was largely working alone, he and Matt Pietrek were my MFC teachers.
Iain.
Codeproject MVP for C++, I can't believe it's for my lounge posts...
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Dear All,
I want to add the special character "&" into my label box, but when I add this, it takes as "_". I know that putting "&" before a character makes the "_" as a shortcut for Alt key.
But I want to include "&" to be displayed in my label box. Is there any way for this ?
Thanks in advance.
Bhanu
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Try with a double &, only one will be displayed.
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Thank you for your kind help. It is working...
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Hallo all,
I have used a List box control and it showing some files full path. I want to show this path one by one when it find out like "Searching in xp". But it display all path at a time. Can any one help me.
Thanks
Regards
saheen
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Shaheen.India wrote: I have used a List box control and it showing some files full path. I want to show this path one by one when it find out like "Searching in xp". But it display all path at a time. Can any one help me.
Have you tried using DlgDirList[^]?
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Do you mean that you run a loop looking for the files, when you find one you add the path to the list, but the list only gets redrawn once your loop is done thus all your hits appear at once? If so, you have 3 options i can think of right now:
1. do the search in a different thread and send/post your hits towards the GUI thread
2. do your search with a timer
3. do your search in idle-time (when your GUI thread has no messages to process)
p.s: You could also try simply forcing your list to be redrawn in your loop with e.g. using RedrawWindow, but that would be an ugly solution.
> The problem with computers is that they do what you tell them to do and not what you want them to do. <
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Thanks for your reply. Yes, I have used it in loop, that's why the problem arise
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