Re: BitBLT question - C / C++ / MFC Discussion Boards

LittleYellowBird2-Jun-10 0:18

2-Jun-10 0:18

Writting a 'maze type game' would be a great project but no one here is going to do your reaearch for you.

If you genuinely want to write a program then try to research it yourself (there are plenty of great articles on this website and Google is a good place to start too), then come back with specific questions.

Good Luck! Thumbs Up | :thumbsup:

Ali

FILE* problem

DevelopmentNoob1-Jun-10 19:12

DevelopmentNoob

1-Jun-10 19:12

Hi,

I'm now using the File* to save the data into text file. But i notice that if the file i want to save is in open mode, then the program will crash. Any way to prevent it? Below is snap of my code..

In *.h file

FILE *handle;

in *.cpp file

fopen_s(&handle,cPathName,"wt");		
fprintf(handle,"<?xml version=\"1.0\"?>\n") // crash at here

Re: FILE* problem

«_Superman_»1-Jun-10 19:50

«_Superman_»

1-Jun-10 19:50

fopen_s has a return value that you must check for errors.
This way you will write only if the open operation was successful, thereby avoiding the crash.

«_Superman_»

I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Polymorphism in C

Re: FILE* problem

Aescleal1-Jun-10 20:28

Aescleal

1-Jun-10 20:28

Are you checking that handle actually points to something? i.e. check the handle for being NULL. If you call any file function with a zero pointer it might very well crash if it dereferences a NULL pointer.

Cheers,

Ash

Re: FILE* problem

Jackson20102-Jun-10 5:08

Jackson2010

2-Jun-10 5:08

Please check if the "handle" is NULL.

fopen_s(&handle,cPathName,"wt");
if (handle != NULL)
{		
    fprintf(handle,"<?xml version=\"1.0\"?>\n")
}

Working is a happy thing!
Enjoy free partition manager!

BitBLT question

ForNow1-Jun-10 17:28

ForNow

1-Jun-10 17:28

Hi,

If use bitblt to change the Background of a bitmap

The later I use that bit map in some other fuction will the background remain or is the bsckground only
valid while the bitmap is selected in the DeviceContext

Thankx

Re: BitBLT question

«_Superman_»1-Jun-10 20:08

«_Superman_»

1-Jun-10 20:08

BitBlt works on a device context.
A device context can only have one bitmap selected into it.
So what ever you draw to that DC will remain valid through out its life time.

So taking the device handle from the device context to draw else where will work as you expect.

«_Superman_»

I love work. It gives me something to do between weekends.

Microsoft MVP (Visual C++)

Polymorphism in C

Re: BitBLT question

ForNow2-Jun-10 1:29

ForNow

2-Jun-10 1:29

Hi,

I have the following code which paints a Gray Baxkground on a Bitmap consisting of a yellow around

and a while background

    CBitmap *bm = new CBitmap;           // Bitmap Object

  bm->LoadBitmap((UINT) IDD_BITMAP);             // LOAD THE ARROW

      CDC *cdcimage = this->GetDC();

  cdcimage->SelectObject(bm);

       CDC cdcimage1, cdctrans;      // dcmask

      COLORREF oldback = cdcimage->SetBkColor(RGB(255,255,255));
  COLORREF oldtext = cdcimage->SetTextColor(RGB(0,0,0));

  cdcimage1.CreateCompatibleDC(cdcimage);
  cdctrans.CreateCompatibleDC(cdcimage);

  cdcimage1.SelectObject(bm);


 BITMAP bm_struct;

 bm->GetBitmap(&bm_struct);                              // get the demensions of ste arrow

 CBitmap bmask;                                     //  Create mask

      bmask.CreateBitmap(bm_struct.bmWidth,bm_struct.bmHeight,1,1,NULL);

      cdctrans.SelectObject(&bmask);

cdcimage1.SetBkColor(RGB(125,125,125));

cdctrans.BitBlt(0,0,bm_struct.bmWidth,bm_struct.bmHeight,&cdcimage1,0,0,SRCCOPY);

cdcimage->BitBlt(0,0,bm_struct.bmWidth,bm_struct.bmHeight,&cdcimage1,0,0,SRCINVERT);
cdcimage->BitBlt(0,0,bm_struct.bmWidth,bm_struct.bmHeight,&cdctrans,0,0,SRCAND);
cdcimage->BitBlt(0,0,bm_struct.bmWidth,bm_struct.bmHeight,&cdcimage1,0,0,SRCINVERT);

cdcimage->SetBkColor(oldback);
cdcimage->SetTextColor(oldtext);

later I pass the handle

stgm.hBitmap = (HBITMAP)*bm;

to an OLE Richedit interface

However the bitmap remain as it on the file with a white background

any ideas

thankx

Re: BitBLT question I think I have to paint into a memry DC

ForNow2-Jun-10 6:47

ForNow

2-Jun-10 6:47

Hi

I do all my painting to CRichedit DC

I think I need do it to a memory DC then give the bitmap handle
to OLE

C++ Socket Number - duration of socket number in server program

simon alec smith1-Jun-10 12:01

simon alec smith

1-Jun-10 12:01

When a new SOCKET is generated by a client connection to the server
I understand the SOCKET in question holds a unique integer number.

What I would like to know is; if the client in question associated with this number logs off or de-connects, is this number then available for other connecting clients or is it ‘gone when its gone’.

I am using the code from Boby Thomas Pazheparampil, May 2006 implementation of the client server text messaging in the articles. Also please note that I have outputted the number associate when a client connects in this program and they roughly start in 1800 series and descended at various intervals(1780,1778 etc) doe anybody know why this is so, and the limits of the number of connections also?

I am developing a program where the appropriate id of auser is associated with the socket.

Thanks in advance for helping

Simon

Re: C++ Socket Number - duration of socket number in server program

Moak1-Jun-10 22:27

Moak

1-Jun-10 22:27

Basically your question is, if the operating system reuses socket handles?

Yes, I would guess that with a long running server application there is no other way for the operating system. On Windows this definitely happens, see Winsock Programmer's FAQ[^]. In my networking applications I separate session/user handling from low-level networking, which means every user gets a unique ID assigned. There are many ways to create an ID, for example use the current UTC time paired with a random value. Alternatively, if you just need an unique internal reference, you could use this pointer of your C++ object.

Not sure if this answered your question?
M

Chat in Europe Java | [Coffee]

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Synchronise Contacts with Exchange Server Mailboxes

Steve Thresher1-Jun-10 8:03

Steve Thresher

1-Jun-10 8:03

I need to synchronise contacts from our DB with user profiles in an exchange server. Can anyone suggest which API / SDK to use to achieve this from a C++ application? The idea is users can flag contacts in our application as being one they want synchonised with their mobile phone eg. each account manager will want contact details for their customer accounts.

mouse related Q

a.k.a BT1-Jun-10 7:19

a.k.a BT

1-Jun-10 7:19

Hi,

This is not exactly a programming Q.

I have wireless HP mouse.

It has two side button for backward / forward page.

I want to map one of the key as ESC.

How I can do it?

BT

Re: mouse related Q

Richard MacCutchan1-Jun-10 7:59

Richard MacCutchan

1-Jun-10 7:59

a.k.a BT wrote:
This is not exactly a programming Q.

So why put it in a forum reserved for C/C++/MFC?

It's time for a new signature.

Re: mouse related Q

a.k.a BT1-Jun-10 8:17

a.k.a BT

1-Jun-10 8:17

if by programming it can be done.

I think its possible. Thats why I posted.

BT

Re: mouse related Q

a.k.a BT1-Jun-10 8:59

a.k.a BT

1-Jun-10 8:59

VK_BROWSER_BACK and VK_BROWSER_FORWARD ,

How to capture these events and through ESC key event globally?

BT

Re: mouse related Q

Richard MacCutchan1-Jun-10 21:23

Richard MacCutchan

1-Jun-10 21:23

a.k.a BT wrote:
if by programming it can be done.

I think its possible. Thats why I posted.

But your first message said :

a.k.a BT wrote:
This is not exactly a programming Q.

It's time for a new signature.

Re: mouse related Q

Software_Developer1-Jun-10 8:59

Software_Developer

1-Jun-10 8:59

http://www.codersource.net/mfc/mfc-tutorials/mfc-handling-messagemaps.aspx[^]

Re: mouse related Q

a.k.a BT1-Jun-10 9:09

a.k.a BT

1-Jun-10 9:09

what I am looking...

want to capture two mouse event globally....and throw ESC key event.

BT

Re: mouse related Q

Stephen Hewitt1-Jun-10 16:56

Stephen Hewitt

1-Jun-10 16:56

A mouse hook[^] might be the way to go.

Steve

Problem with Modeless dialogs

Sreenivas0031-Jun-10 5:28

Sreenivas003

1-Jun-10 5:28

I have a derived CModeless Class form CDialog class which is used for creating modeless dialogs. I have derived 2 new dialog classes from the CModeless. I have opened the two dialogs since they are modeless. After OnOK of the dialog i must create the dialog again, for both the dialogs. but i am unable to see the dialog when OnOk button until the other dialog is closed.
Can any one tell me the solution for the problem.

sreenivas003@yahoo.co.in

Re: Problem with Modeless dialogs

Sarath C1-Jun-10 14:37

Sarath C

1-Jun-10 14:37

Why you can't send WM_CLOSE message to the other dialog before recreating it?

BTW, why it's necessary to have CDialog->CModelessDialog>CXXXDailog/CYYYDialog?

-Sarath.

My blog - Sharing My Thoughts

Rate the answers and close your posts if it's answered

Child Window

john56321-Jun-10 4:20

john5632

1-Jun-10 4:20

Hi,

How can I make a modeless dialog as child to another dialog using code.
I tried ModifyStyle(0,WS_CHILD) in initdialog but not worked..

How to do that?

Re: Child Window

Niklas L1-Jun-10 5:16

Niklas L

1-Jun-10 5:16

Usually you Create() the modeless dialog using the other window as its parent, setting window sizes and such.

home

Re: Child Window [modified]

Software_Developer1-Jun-10 9:02

Software_Developer

1-Jun-10 9:02

Create a modeless dialog box as child window[^]

http://www.blenkers.de/interface/modelesschild.htm[^]

http://www.voidnish.com/Articles/ShowArticle.aspx?code=gettingmodeless[^]

..

modified on Wednesday, June 2, 2010 2:42 AM

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