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I've never worked with USB devices. Since I've been working on software
that handle phone connected to USB I need all the help available.
Please direct me to a link or give me the name of class i can use that support
USB connection.
Thenk you,
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It depends a lot of the type of device you are working with. If it is an USB-to-serial device, then you can simply open a virtual COM port and work as if it was a COM port.
If this is another type of device, then there is a driver supplied with it and you need to get a handle to this driver with CreateFile and then send I/O commands by using the DeviceIOControl function. The codes you need to supply to the functions are described in the documentation supplied with the driver (if any).
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Hi Experts,
I am trying to Display a Bitmap Data that is stored in the array (Memory) on to the Display device. I tried to write the following code but could not succeed in displaying the image on the display device. Could anybod help me to fix this problem?
/*code*/
int DrawImage(HWND hwnd)
{
unsigned char *alligned= (unsigned char *)malloc(352 * 288 * 4);
if(alligned == NULL )
return -1;
/* Data to be displayed */
memset(alligned,0x77,1056);
/*Device Context */
HDC hdc = GetDC(hwnd);
if(hdc == NULL)
return -1;
/* Creating Memory Device Context */
HDC memDC = CreateCompatibleDC ( hdc );
if(memDC == NULL)
return -1;
/* Creating a Bitmap */
HBITMAP memBM = CreateCompatibleBitmap ( hdc, 352, 288 );
if(memBM == NULL)
return -1;
/*Setting the array of bits to Bitmap */
SetBitmapBits(memBM,1056,alligned);
/*Selecting the Bitmap Objects */
HBITMAP oldobj = (HBITMAP)SelectObject ( memDC, memBM );
if(oldobj == NULL)
return -1;
/*Try to Display */
BOOL test = BitBlt(hdc,0,0,352,288,memDC,0,0,SRCCOPY);
if(!test)
return -1;
return 0;
}
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DAMN !!! how is it so difficult for people to post ones code samples inside a <pre></pre> block ??? 
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Thanks for your suggestion. I am using this type of message board for the first time 
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You should give more details about what you see on the screen.
Only a few words.
Do not forget to clean up your temporary device contexts,
and/or bitmaps.
According to the code you have submitted you should get trash
on most of your window. 352*288*4 = 405504. So 1056 will not do.
Also 0x77, will give you some transparency.
As this is C++, you could try using MFC classes, or GDIPlus.
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I am trying to display different
images that are strored in the memory,
I was looking for some sample code
so that I could draw somthing on the window screen.
I tried to use CreateBitmap and CreateCompatibleBitmap
but could not succeed in displaying anything on the sceen.
Thanks for you correction
but even then I could not be able to see anything on the screen
Let me try and use GDI+, I am not allowed to use MFC
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You'll find sample code there for the DIBs:
http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dngdi/html/msdn_dibs2.asp
Hope this helps
Else in GDI+, you can
- create a Bitmap object
- call LockBIts
- modify the bits
- call UnlockBits
- create a Graphics object
- call DrawImage
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Thanks Pierre and Mark,
The link you provided certainly helped me to get through the problem. SetDIBits() function which I should have used.
Thank you very much
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Besides the answers you've already received, you may want to use device-independent bitmaps.
Your code assumes the display device is configured to 32-bit.
Check out CreateDIBSection() for a bitmap you can select into a DC and also have a pointer
to the image bits.
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Thanks Mark,
Based on your suggestion I modify the following code and used CreateDIBSection() function
instead of CreateBitmap() or CreateCompatibleBitmap() functions.
But Still end up unsuccessfully.
(Expected close to black color, is not appearing on the window)
All the functions I use returning successfully but the result is NOT GOOD. I am running outof options, Could you suggest me any other options other than GDI+ or MFC
<big><code>
BITMAPINFO bi; ZeroMemory(&bi,sizeof(bi));
BITMAPINFOHEADER &bih = bi.bmiHeader;
bih.biSize=sizeof(bih);
bih.biWidth=352;
bih.biHeight=288;
bih.biBitCount=24;
bih.biSizeImage = ((bih.biWidth*bih.biBitCount/8+3)&0xFFFFFFFC)*bih.biHeight;
:
:
void* img_ptr = NULL;
HBITMAP memBM =CreateDIBSection(hdc,(BITMAPINFO*)&bih,DIB_RGB_COLORS,&img_ptr,NULL,0);
if(img_ptr != NULL)
{
alligned =(unsigned char *)img_ptr;
memset(alligned,0x11,bih.biSizeImage);
}
</code></big>
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hi all,
Please help me out !
give some material or book name to learn ease COM.
Thanks & Regards
rakesh baldha
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http://www.develop.com/essentialcom/[^]
Peace!
-=- James
If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Avoid driving a vehicle taller than you and remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
DeleteFXPFiles & CheckFavorites (Please rate this post!)
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I am trying to create a visualization for WMP that uses a webcam in it. For the moment i just want to preview the webcam in the visualization but im finding it hard to do so.
Can anyone help me out here?
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Hi all,
Can anyone please tell me , where can I get GDI+ in VC++ 6.0 for download.
Thanks
George
-- modified at 8:39 Tuesday 7th November, 2006
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Search for the latest Platform SDK install. Even though it technically no longer supports VC++ 6.0(!), you should be able to get the redistributes necessary to build under VC++ 6.0.
Peace!
-=- James
If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Avoid driving a vehicle taller than you and remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
DeleteFXPFiles & CheckFavorites (Please rate this post!)
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class A
{
public:
void print()
{
printf("print A");
}
virtual void write()
{
printf("write A");
}
};
class B: public A
{
public:
void print()
{
printf(" print B");
}
virtual void write()
{
printf("write B");
std::cout<<"try";
}
};
int main()
{
// A *pA = new A;
// pA->print();
// pA->write();
A *pB = new B;
pB->print();
pB->write();
return 0;
}
Thanks & Regards
rakesh baldha
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A virtual table is a table containing the addresses of all the virtual functions of the class that was instancied (so that the call can be redirected to the correct derived class function). In your example, print was not declared as virtual so it is not in the vtable but write is virtual (so it is in the vtable).
So in this statement:
A *pB = new B;
pB was declared as a pointer to an object A and was instancied as a pointer to an object B. So, the virtual table contain one virtual function (the write function) that is redirected to the write function of the B class. For the compiler pB has been declared as a pointer to A so if you call print, it will call print from the class A (the call is not redirected because the function is not in the vtable). When you call write, the call will be redirected to write of the B class because of the vtable.
I hope this is clear...
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thank you very much.
Thanks & Regards
rakesh baldha
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You're welcome.
Please next time use the pre or code tags and indent your code correctly so it will be more readable.
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Hello,
I have a problem with static variable into MFC dll .
In header I have a static variable:
static UINT OPC_SERVER_TYPE;
In source I have :
UINT OPCServer::OPC_SERVER_TYPE=20;
When I compil my project were I use the lib and dll and I compil the project with "Use MFC in a Static Library" I get those error:
GMMSoftware_V04.00b.obj : error LNK2001: unresolved external symbol "public: static unsigned int OPCServer::OPC_SERVER_TYPE" (?OPC_SERVER_TYPE@OPCServer@@2IA)
When I compil my project with "Use MFC in a Shared DLL" it work good!
What can I change in my class into MFC dll project to fix the problem ?
Thank you!
AutreChien
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If you are using MFC in a DLL and in an application (EXE) you may want to take a look at this:
Extension DLLs[^]
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Hi,
I am making a dialog based application on VC7 using MFC.
At run time I am creating a ListCtrl on this dialog box.
But Horz/Vert Scroll Bar are not showing in my ListCtrl.
Reply soon,
Thanks,
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They will not be shown unless, no. of items in listctrl are more that maximum possible visible items in your control.
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The number of items are more but the scroll bars are not shown. While if i do the same in VC6 then they are shown. I have tried to set WS_VSCROLL and ShowScrollBar(WS_VERT,TRUE)
but no success.
-------//-----
// //
//-----
____// \\
---// \\AKESH
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