typedef tweak - C / C++ / MFC Discussion Boards

Re: How to change the property of a modem connection in WINXP?(Problem with RAS)

hizfp22-Nov-07 16:15

hizfp

22-Nov-07 16:15

No one can help me?

Print Edit control!!!

Gofur Halmurat21-Nov-07 8:53

Gofur Halmurat

21-Nov-07 8:53

hello,
Does anyone know how to print CEdit's text?
any ideas?

thanks

Re: Print Edit control!!!

bob1697221-Nov-07 9:19

bob16972

21-Nov-07 9:19

You will get the best results and not have to worry about if the text is scrolled off the CEdit control if you get the text and use CDC::TextOut or CDC::DrawText. However, I find most people have a negative reaction to that suggestion so if your determined to literally print the CEdit to a device context, CWnd::Print should do the job.

Just be forwarned, if you don't modify something (viewport extents, windows extents, etc...) in an appropriate mapping mode, it's gonna come out really, really, tiny on your printer. The best way to save a tree is to output your print tests to an Adobe Acrobat, PrimoPDF , or that new snazzy Vista XML print driver to see the results. That way you can zoom in really, really close to verify my statement.

After that you can experiment until way after Thanksgiving trying everything you can think of to get around all the pitfalls associated with trying to print a CEdit control (reliably) in all possible contexts and scenarios until you are ready to pull your hair out.

At that point, you can go back to my first suggestion and use TextOut or DrawText and smile once again knowing you did the right thing.

Big Grin | :-D

Re: Print Edit control!!!

Hamid_RT21-Nov-07 19:05

Hamid_RT

21-Nov-07 19:05

You can get your data with GetWindowText of edit control and use of TextOut or DrawText for print it.

Why do my Controls flicker ? (src incl.)

abiemann21-Nov-07 7:44

abiemann

21-Nov-07 7:44

In my VS8 MFC Dialog exploratory-app, the listbox and OK buttons flicker. I've tried the Double Buffer code (http://www.codeproject.com/bitmap/drawing_without_flicker.asp[^]) like this:

void CFlickerTestDlg::OnPaint()<br />
{<br />
    CPaintDC dc(this); // device context for painting<br />
<br />
    CRect rcClient;		<br />
    GetClientRect(rcClient);	// See Note 1<br />
<br />
    CDC MemDC,*pDC;<br />
    CBitmap MemBitmap;<br />
<br />
    pDC = this->GetDC();         // Get Current DC<br />
    MemDC.CreateCompatibleDC(pDC);<br />
    MemBitmap.CreateCompatibleBitmap(pDC,rcClient.right,rcClient.bottom);<br />
<br />
    CBitmap *pOldBitmap = MemDC.SelectObject(&m_BmpTarget);<br />
    //CBrush bkBrush(HS_FDIAGONAL,RGB(0,rand()%255,0));	// See Note 2<br />
    //MemDC.FillRect(rcClient,&bkBrush);<br />
<br />
    pDC->BitBlt(0,0,rcClient.right,rcClient.bottom,&MemDC,0,0,SRCCOPY);	//See Note 3<br />
    MemDC.SelectObject(pOldBitmap);<br />
}

but that didn't help, the listbox and OK buttons still flicker.
(also, I don't understand why my static image is covered up by some grey layer - but my main priority is the annoying flicker)

I've uploaded my project (255KB) here in a .zip:
http://www.webfilehost.com/?mode=viewupload&id=4066339[^]
There's a countdown timer on the bottom-right of the page that changes to a download link (I don't have any online webspace to share files so I had to resort to one of these free sharing services)

I'd be SO grateful for any help

Re: Why do my Controls flicker ? (src incl.)

Mark Salsbery21-Nov-07 9:49

Mark Salsbery

21-Nov-07 9:49

The code you posted does nothing to prevent flicker.

I've been through your code and made some modifications to fix the flicker.

Having a picture control behind all the other controls is the problem.
It prevents you from clipping the other controls to prevent flicker.

I added the WS_CLIPCHILDREN style to the dialog, deleted the picture control from
the dialog's resource, and instead draw the bitmap to the window in response to WM_ERASEBKGND.
This way, Windows automagically clips all the child controls, so you don't have to redraw them on every
timer event.

Shoot me an email here and I'll send the changes in a reply.

BTW, the code leaks GDI resources on every timer event Smile | :)

I didn't look for those leaks.

Mark

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Project cache file of 42meg - deleting/denying

syscwl21-Nov-07 4:41

syscwl

21-Nov-07 4:41

VS2005 C++ latest UPD. VS seems extremely lethargic lately. I now find its producing a "xxxxcache.dat" file, where xxxx is the project name. THis file runs 40 to 50 MEG. Whats causing this and how can I stop it from ocurring. It certainly was not doing this a year ago.

typedef tweak

LiYS21-Nov-07 4:28

LiYS

21-Nov-07 4:28

typedef struct { 
   DWORD dwValue;
   BYTE  bDummy[1020]; 
} CELL, *PCELL;


typedef CELL SPREADSHEET[g_nNumRows][g_nNumCols];
typedef SPREADSHEET *PSPREADSHEET;


CELL* m_pArray = (CELL*) VirtualAlloc(NULL, g_nNumRows * g_nNumCols, 
      MEM_RESERVE | MEM_TOP_DOWN, PAGE_READWRITE);

SPREADSHEET& g_ss = * (PSPREADSHEET) m_pArray ;

The above code snippet avoid to explicitly allocate for "g_nNumRows" * "g_nNumCols" cells, right? But reading it makes my head spinning, I think most of it origin from "typedef CELL SPREADSHEET[g_nNumRows][g_nNumCols];". Some statements just don't make sense to me grammatically: Why the reference '&' is needed here? What exactly happened when "* (PSPREADSHEET) m_pArray" was executed.(I'm always wondering what happens when something is casted to a build in and user defined data type, I've seen casting from PVOID to PBYTE for pointer manipulations)

Thank,

Re: typedef tweak

led mike21-Nov-07 4:40

led mike

21-Nov-07 4:40

LiYS wrote:
I'm always wondering what happens when something is casted

Don't wonder. Study the subject, get or find materials (like this for example[^] ) and read it until you understand.

Re: typedef tweak

jhwurmbach21-Nov-07 6:15

jhwurmbach

21-Nov-07 6:15

LiYS wrote:
Why the reference '&' is needed here?

Where?

Let's think the unthinkable, let's do the undoable, let's prepare to grapple with the ineffable itself, and see if we may not eff it after all.
Douglas Adams, "Dirk Gently's Holistic Detective Agency"

Re: typedef tweak

led mike21-Nov-07 6:33

led mike

21-Nov-07 6:33

jhwurmbach wrote:
SPREADSHEET& g_ss = * (PSPREADSHEET) m_pArray ;

Re: typedef tweak

jhwurmbach21-Nov-07 6:37

jhwurmbach

21-Nov-07 6:37

:-OOk. Well.... Blush | :O

I second the question of the original poster: Why are we taking a reference from that pointer?

Re: typedef tweak

Mark Salsbery21-Nov-07 7:00

Mark Salsbery

21-Nov-07 7:00

That little snippet of code makes my head hurt.

A C++ spreadsheet class implementing a multidimension array of CELL structs
is SO much cleaner to use, encapsulated, typesafe, etc., etc...

Hapy Thanksgiving man!
Beer | [beer]

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: typedef tweak

led mike21-Nov-07 9:01

led mike

21-Nov-07 9:01

Mark Salsbery wrote:
That little snippet of code makes my head hurt.

Yeah, I thought about trying to explain that the wrong question was being asked but figured what the heck, they're all gone fishin

Re: typedef tweak

Mark Salsbery21-Nov-07 6:57

Mark Salsbery

21-Nov-07 6:57

CELL* m_pArray = (CELL*) VirtualAlloc(NULL, g_nNumRows * g_nNumCols, <font color="Red"><-- shouldn't that be g_nNumRows * g_nNumCols * sizeof(CELL)</font>

Mark Salsbery
Microsoft MVP - Visual C++
Java | [Coffee]

Re: typedef tweak

Nathan Holt at EMOM21-Nov-07 10:49

Nathan Holt at EMOM

21-Nov-07 10:49

The easiest way to understand typedef is that it works the same way as if you were declaring a variable. If you were declaring a 2d array of cells, you could use CELL array[g_nNumRows][g_nNumCols];. If you put a typedef in front of the declaration, it gives a name to the type that such a variable would be.

The & is used to create a reference to the SPREADSHEET that will act like a value. In many cases, this is a good way to avoid using * for all your variable references, and to make sure you don't accidentally change the value of the pointer it hides. In this case, the effects are complicated by the way pointers act like arrays, so this might not be good code to start learning from.

The more appropriate way to write the last line might make more sense:
SPREADSHEET& g_ss = *reinterpret_cast<PSPREADSHEET>(m_pArray)
In this case, the C array/pointer equivalence is used again. Casting to and from void * is more common, and it is used for code that works on pointers without regard to the type pointed to.

I can see a couple problems in the code you have posted. The names of the array dimensions look like variable names, but array sizes declared that way have to be compile time constants. Also, there seems to be a sizeof(CELL) missing in the VirtualAlloc statement.

Nathan

Re: typedef tweak

LiYS21-Nov-07 17:41

LiYS

21-Nov-07 17:41

Thanks Nathan,

Nathan Holt at EMOM wrote:
The & is used to create a reference to the SPREADSHEET that will act like a value. In many cases, this is a good way to avoid using * for all your variable references, and to make sure you don't accidentally change the value of the pointer it hides. In this case, the effects are complicated by the way pointers act like arrays, so this might not be good code to start learning from.

This & references to array's address?

To me cast into user defined type in this scenario is just like stuff the memory into the target type's structure in byte.

Does it take much time to do such a user interface?

followait21-Nov-07 4:24

followait

21-Nov-07 4:24

http://img.photo.163.com/NMyVjJovPuDSLF5B0l9lcg==/159033361845675826.jpg[^]

Re: Does it take much time to do such a user interface?

led mike21-Nov-07 4:35

led mike

21-Nov-07 4:35

A user interface? All I see is an image.

Re: Does it take much time to do such a user interface?

followait21-Nov-07 4:38