C / C++ / MFC

How could I run one of my class member Functions in a new thread:

8-Apr-10 3:08

i wrote an article about it: A Quick Drive Manager[^]

Press F1 for help or google it.
Greetings from Germany

m_code8-Apr-10 2:09

Re: How could I run one of my class member Functions in a new thread:

8-Apr-10 2:09

How could I run one of my class member Functions in a new thread:
ex:

class e
{
	...
public:
	void myMainLoopFunc(void){...}
};

I want to run myMainLoopFunc in a new thread what should I do?

Adam Roderick J8-Apr-10 2:20

Adam Roderick J

8-Apr-10 2:20

I think you should get familiar with AfxBeginThread([^])

And its usage, surely u will understand how to do that by understanding about AfxBeginThread.
well here is a code. Make the myMainLooFunc with the specified function signature and static(To know why, check the msdn for more help).

class e
{
	...
public:
	static UINT myMainLoopFunc(LPVOID kodata)
        {
         ...
        }
};

Величие не Бога может быть недооценена.

Re: How could I run one of my class member Functions in a new thread:

Cool_Dev8-Apr-10 2:24

Cool_Dev

8-Apr-10 2:24

pass the class instance to thread proc as argument and call function from there

e *pE = ...   //assign running instance of e. assign this pointer if from inside the class e.
AfxBeginThread(fnThreadProc, p);

//Thread proc definition
UINT fnThreadProc(LPVOID lpParam)
{
  E *pE = (*pE)lpParam;
  pE->myMainLoopFunc(); //call any public function in class e.
}

Re: How could I run one of my class member Functions in a new thread:

m_code8-Apr-10 3:03

Re: How could I run one of my class member Functions in a new thread:

8-Apr-10 3:03

Good idea,
But I have faced some problems.
My e class Objects just get a HWND object in their contructor argument
and draw something on it, in myMainLoopFunc() method How ever the code runs with no error But nothing drwan in the window.
But without threading it works perfectly.
Do you have any idea what's the problem.

Message Removed

8-Apr-10 3:28

Eugen Podsypalnikov

8-Apr-10 3:28

Message Removed

m_code8-Apr-10 3:44

Re: How could I run one of my class member Functions in a new thread:

8-Apr-10 3:44

sorry But i don't understand your point of view and why should i do this?

KarstenK8-Apr-10 3:41

Re: How could I run one of my class member Functions in a new thread:

8-Apr-10 3:41

make the HWND to the start parameter of the Threadfunc and construct in the func the new object. Sleepy | :zzz:

Press F1 for help or google it.
Greetings from Germany

m_code8-Apr-10 3:50

Re: How could I run one of my class member Functions in a new thread:

8-Apr-10 3:50

That made the same problem either, nothing is drawn in the HWND while the dawing methods executed one after another

KarstenK8-Apr-10 4:09

CreateBitmapIndirect() doesnt create bitmap

8-Apr-10 4:09

can you show me some code?

Press F1 for help or google it.
Greetings from Germany

globus0008-Apr-10 2:08

globus000

8-Apr-10 2:08

Hello
I've got the following problem with CreateBitmapIndirect(). I've got bitmap data - width, height, bits-per-pixel and array of bits. I'm trying to create HBITMAP by calling CreateBitmapIndirect, but when it's created the biBits of the BITMAP object is NULL. Here is the cpde"

int size = 0, width = 0, height = 0, planes = 0, bpp = 0, r = 0, g = 0, b = 0;
unsigned char* pBits = NULL;
CComVariant data;
hr = pIShellBmp->GetData( &width, &height, &planes, &bpp, &data ); //my interface which returns serialized bitmap
hr = pIShellBmp->GetColors( &r, &g, &b );
            if( SUCCEEDED(hr) )
            {

                CComSafeArray<BYTE> bits( data.parray );
                pBits = new unsigned char[ bits.GetCount() ]; // this is array of bits in bitmap - it's content of other BITMAP::biBits which I store in IShellBmp interface in COM server (local service)
                for( int i = 0; i < bits.GetCount(); ++i )
                {
                    pBits[i] = bits.GetAt( i );
                }

                BITMAP bmp;

                bmp.bmType = 0;
                bmp.bmBitsPixel = bpp;
                bmp.bmHeight = height;
                bmp.bmPlanes = planes;
                bmp.bmWidth = width;
                bmp.bmWidthBytes = width * bpp / 8 + (width * bpp / 8)%2;
                bmp.bmBits = pBits;


                HBITMAP hBitmap = CreateBitmapIndirect( &bmp ); // THIS IS OK - bitmap created


                BITMAPINFO bmi;
                bmi.bmiHeader.biSize = sizeof(BITMAPINFO);
                bmi.bmiHeader.biBitCount = bpp;
                bmi.bmiHeader.biClrImportant = 0;
                bmi.bmiHeader.biClrUsed = 0;
                bmi.bmiHeader.biCompression = BI_RGB;
                bmi.bmiHeader.biHeight = height;
                bmi.bmiHeader.biPlanes = planes;
                bmi.bmiHeader.biSizeImage = 0;
                bmi.bmiHeader.biWidth = width;


                if( hBitmap == NULL )
                {
                    DWORD err = GetLastError();
                    hr = E_FAIL;
                }//if
                else
                {
                    DWORD err = SetDIBits( CreateCompatibleDC(NULL), hBitmap, 0, bmp.bmHeight, pBits, &bmi, DIB_RGB_COLORS );  // This line returns 0 - ???
                    err = GetLastError(); // error code is 0
                    GetObject( hBitmap, sizeof(BITMAP), &bmp ); // bmp.bibits contains NULL - why??
                    WriteBMPFile( hBitmap, _T("c:\\received.bmp"), CreateCompatibleDC( NULL ) );
                }//else
            }//if

For some reasons the lines in bold fail and there is no error code. Can you please help me - where I'm wrong?

Re: CreateBitmapIndirect() doesnt create bitmap

KarstenK8-Apr-10 3:23

Re: CreateBitmapIndirect() doesnt create bitmap

8-Apr-10 3:23

HBITMAP hBitmap = CreateBitmapIndirect( &bmp );
//check out
GetObject( hBitmap, sizeof(BITMAP), &bmp );
//or draw the bitmap for visual check

//isnt SetDIBits() double done
read: http://msdn.microsoft.com/en-us/library/dd144904%28VS.85%29.aspx[^]

Press F1 for help or google it.
Greetings from Germany

Jonathan Davies8-Apr-10 5:23

Jonathan Davies

8-Apr-10 5:23

Should you be setting bmi.bmiHeader.biSizeImage before calling SetDIBits? I only say this because I found the following I'd used which uses GetDIBits to calculate it's value:

...

// Calculate the biSizeImage parameter using GetDIBits or manually if this fails
int ScanLines = GetDIBits(hMemDC,hBmp,0,B1Win.ylen,NULL,lpbmInfo,DIB_RGB_COLORS);
if(lpbmInfo->bmiHeader.biSizeImage == 0)
    lpbmInfo->bmiHeader.biSizeImage = ((((lpbmInfo->bmiHeader.biWidth * lpbmInfo->bmiHeader.biBitCount) + 31) & ~31) >> 3) * lpbmInfo->bmiHeader.biHeight;



// Copy bits from RGB888 to 24 bit DIB and inverting bitmap 
ScanLines = (int)(InControl.VideoRoi.ylen);	// SetDIBits inverts if height is -ve

// biHeight originally set -ve here
ScanLines = SetDIBits(hMemDC,hBmp,0,ScanLines,BDBoard.pcnvBuffer,lpbmInfo,DIB_RGB_COLORS);

...

Widest Character and Height of the character

shiv@nand8-Apr-10 1:13

shiv@nand

8-Apr-10 1:13

I want to know the widest character and height of "MS Sans Sarif" Font Type. The Characters = {abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ},font size may be in between 8 to 50.

Eugen Podsypalnikov8-Apr-10 1:37

Eugen Podsypalnikov

8-Apr-10 1:37

Try it

CSize GetMaxCharSize(CDC* pcDC, CFont* pcFont)
{
  CSize csizeResult(0, 0);
  if (pcDC && pcFont) {
    CGdiObject* pcOldFont = pcDC->SelectObject(pcFont);
    TEXTMETRIC tm = {0};
    pDC->GetTextMetrics(&tm);
    csizeResult.cx = tm.tmMaxCharWidth;
    csizeResult.cy = tm.tmHeight;
    pcDC->SelectObject(pcOldFont);
  }
  return csizeResult;
}

virtual void BeHappy() = 0;

Adam Roderick J8-Apr-10 1:41

Adam Roderick J

8-Apr-10 1:41

I support the above. Smile | :)

Величие не Бога может быть недооценена.

shiv@nand8-Apr-10 1:49

shiv@nand

8-Apr-10 1:49

please give me an example ?

Eugen Podsypalnikov8-Apr-10 2:01

Eugen Podsypalnikov

8-Apr-10 2:01

It could be something like this Smile | :)

/*virtual*/ void CYourView::OnInitialUpdate()
{
  CBaseOfYourView::OnInitialUpdate();

  /*CFont*/ m_cFont.CreatePointFont(120, _T("Arial")); // 12pts * 10
...
}

/*virtual*/ void CYourView::OnDraw(CDC* pDC)
{
  CSize cMaxCharSize(GetMaxCharSize(pDC, &m_cFont));
  CRect cMaxCharRect(CPoint(100, 100), cMaxCharSize);
  pDC->FillSolidRect(cMaxCharRect, RGB(0, 128, 200));
...
}

virtual void BeHappy() = 0;

shiv@nand8-Apr-10 2:17

shiv@nand

8-Apr-10 2:17

thank you