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For example:
CPoint*pc=new CPoint;
//delete it in an array way:
delete []pc;
is the delete harmful?
if it is harmful, I have to add a flag in collection to record which pointer is for single object as example above or for array.
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Yes, this can lead to troubles because allocating an array is not the same as allocating a single instance. For the array, there is first the number of instances that is saved just in front of the allocated memory. So, using delete[] it will try to read the number of instances first.
But why use a flag ? In your case you know if you use new or new[] (and normally you always now that).
If you do this:
CPoint* pc = new CPoint[1];
This is the same as allocating an array thus, delete[] will be ok.
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Cedric Moonen wrote: CPoint* pc = new CPoint[1];
good idea
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includeh10 wrote: CPoint*pc=new CPoint;
//delete it in an array way:
delete []pc;
wrong way! you have to create that the array way before deleting!
"Opinions are neither right nor wrong. I cannot change your opinion. I can, however, change what influences your opinion." - David Crow
cheers,
Alok Gupta
VC Forum Q&A :- I/ IV
Support CRY- Child Relief and You
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i have 2 CEdit (CDialog) i want to search if the text from CEdit (1) matches with 1 record (in my database )( my database visualfoxpro - CRecordset - snapshot ) and the matches must fill in the second CEdit ! how ?
thanks !
Bravoone
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I find the easiest way is with a parameterized recordset. Please do not ask what that is without searching for it yourself first. You can either use Google, or peruse the CP articles. Hint: one of my articles has an example.
"Money talks. When my money starts to talk, I get a bill to shut it up." - Frank
"Judge not by the eye but by the heart." - Native American Proverb
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i just want to integrate the mysql installer inside the c++ appliction.
I think its possible
since i had seen some of the client side installation software that performs the said task.
if i run the c++ application, it will prompt for the mysql installation.
The mysql installer then will be installed in the client machine.
If any dude out there possibily put some light into this matter will be heartly appreciated...
never be late or time will ate
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Hi,
I have created a List control in report view using gridlines as follows
m_StoreItems.SetExtendedStyle(LVS_EX_FULLROWSELECT | LVS_EX_GRIDLINES);
I need to create a combo box in a column seperated by gridlines.
Can u please help me.
thannks in advance.
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I want to remove the frame for SDI Application?
How can i do it?
and even menu and tool bar also i want to remove..
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You need to remove WS_OVERLAPPEDWINDOW style from windows style you are using
Make your CMainFrame::OnCreate function look like this
int CMainFrame::OnCreate(LPCREATESTRUCT lpCreateStruct)
{
if (CFrameWnd::OnCreate(lpCreateStruct) == -1)
return -1;
ModifyStyle(WS_OVERLAPPEDWINDOW,0);
}
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Thank you,
i want to know how to put colors for the windows and for the controls which is on the window
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you need to override OnPaint if window is CMainFrame.For controls you need to make them owner drawn, and handle its appearance in OnDrawItem.
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i Want to get the Coordinates of the of my MDI Window, from a function of the class defined Below
class CGUIControlFrame : public CMDIChildWnd {
}
void CGUIControlFrame::OnDestroy()
{
.
.
GetParentFrame()->GetWindowRect(Rect);
.
.
}
I have Used GetParentFrame()->GetWindowRect(Rect); to get the coordinates But its is Not working.
Can Any one help me.
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you can't get it there. Window no longer exists at that point.
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I am writing a graphic design tool. I am using a device context to produce the image on screen. Now I want to be able to print the image to the printer. What I am doing so far is:
Create the screen device context : CDC *m_pDC = CreateDC ();
Do all kinds of weird and wonderful things to produce the image (all of this works, since I do get the image I want on screen)
When the user presses the Print option from the menu, I use the CPrintDialog class to select the printer, and subsequently I get a HDC by “CPrintDialog Print.CreatePrinterDC ();”
Then I calculate the size on paper by the following piece of code:
POINT point;
POINT start;
point.x = GetDeviceCaps (hDC, PHYSICALWIDTH);
start.x = GetDeviceCaps (hDC, PHYSICALOFFSETX);
point.x -= (start.x*2);
point.y = GetDeviceCaps (hDC, PHYSICALHEIGHT);
start.y = GetDeviceCaps (hDC, PHYSICALOFFSETY);
point.y -= (start.y*2);
DPtoLP (hDC, &point, 1);
DPtoLP (hDC, &start, 1);
I already have a POINT named “Source”, that holds the size of the screen DC.
Then I call:
if (!StretchBlt (hDC, start.x, start.y, point.x, point.y, m_pDC->GetSafeHwnd (), 0, 0, Source.x, Source.y, SRCCOPY))
And this is where all goes wrong! This fails, and the error message (as obtained by FormatMessage and GetLastError) says: “The parameter is incorrect”
As far as I can see, the size on paper is correct, since I also write a (test) rectangle with these positions: Rectangle (hDC, start.x, start.y, point.x, point.y); and this produces a rectangle on paper with the size and position as I would expect.
Can anyone help me out here.
William
-- modified at 7:29 Thursday 17th August, 2006
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Sarath,
Thanks for the tip. I checked the link, but it does not solve my problem, since it does not refer to sending the captured image to the printer. I do have a device context with a valid image. However, when I try to copy this image into a printer device context (using StretchBlt), I get an error message.
William
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Before using stretchblt, i think you need to set SetStretchBltMode
printing to DC is not a big deal. it's same as using CDC
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some devices cannot handle large bitmaps (see GetDeviceCaps(...RASTERCAPS), so you have to do your output in bands. some devices cannot do StretchBlt or StretchDIBits (again, see GetDeviceCaps)
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Engberts wrote: if (!StretchBlt (hDC, start.x, start.y, point.x, point.y, m_pDC->GetSafeHwnd (), 0, 0, Source.x, Source.y, SRCCOPY))
6th parameter of API is HDC,whats is m_pDC->GetSafeHwnd ()?
I guess you are passing incorrect type of parameter. It should HDC(source).
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Sorry, this is a typing error, I of course used GetSafeHdc () and not GetSafeHwnd ().
Meanwhile however, I think I found the solution. Since I am copying bitmaps between diferrent devices, I cannot directly BitBlt or StretchBlt between them. I am now using GetDIBits to get the device independant bits out of the screen's device context and then use StretchDIBits to move them into the printer's device context. This does require a lot of programming, but it does result in the required image on paper.
Thanks to you all for your efforts!
William
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Never mind. Importantly, you shared your solution, that's great !
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Hi! i want to write a '.txt' file getting data from a 'multiline edit box'. when i want to go to the next line in an edit box do i press ctrl+enter key? when i use this it gives an extra space character (" ") which spoils the format in the text file i am writing in.
i have also used 'endl;' in the instruction for writing to a file.
outfile << testdata << endl;
if i dont give endl; it gives me two line spaces in between each line in the text file, which again ruins the required file format. does anyone know what i can do to overcome this problem?
thanks!
meriawaz
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