Non-static members not accessible in static function - c++

Question

I have defined a function
HRESULT AMEPreviewHandler:: CreateHtmlPreview()
{
ULONG CbRead;
const int Size= 115000;
char Buffer[Size+1];
HRESULT hr = m_pStream->Read(Buffer, Size, &CbRead );
//this m_pStream is not accessible here even it is declared globally. the program is asking me to
// declare it static because this CreateHtmlPreview() function called
//inside the Static function (i mean here :-static CreateDialog\WM_Command\CreateHtmlPreview();)
//but if i declare it static the two problems arised are
//(1.) It is not able to access the value of the m_pStream which is defined globally.
//(2.)If i declare it static globally then there are so many other function which are using this
// value of m_pStream are not able to access it because they are non static.
}
It is declared static somewhere in my program like this:
static HRESULT CreateHtmlPreview(); //i have declared it static because i am calling this function from DialogProc function.If i dont create it static here it dont work
//The function CreateHtmlPreview() is called inside the DialogProc function like this-
BOOL CALLBACK AMEPreviewHandler::DialogProc(HWND m_hwndPreview, UINT Umsg, WPARAM wParam, LPARAM lParam)
{......
case WM_COMMAND:
{
int ctl = LOWORD(wParam);
int event = HIWORD(wParam);
if (ctl == IDC_PREVIOUS && event == BN_CLICKED )
{
CreateHtmlPreview(); //here i am calling the function
return 0;
}
}
}
So what can be done to make the value of non static m_pStream accessible in the static CreateHtmlPreview() function definition ?

Answer 1

In static class functions you can access to only static class members.

Answer 2

What if you make CreateHtmlPreview() a free function?
What if you make it just create an html preview (instead of also reading from a stream)?
void CreateHtmlPreview(const char * buffer, int size)
{
//...
}
Then read the data from the proc, and call it in DialogProc
//...
m_pStream->Read(Buffer, Size, &CbRead );
CreateHtmlPreview(Buffer, Size);
You will probably need to make the function return the preview to be any use though.
You do say you need to make it
static because i am calling this function from DialogProc function
however, the DialogProc is not static (in the code you have posted), so I don't see what the problem would be.

Answer 3

Can't you just pass the m_pStream var as a function argument?
Instead of defining the function this way
HRESULT AMEPreviewHandler:: CreateHtmlPreview()
{
ULONG CbRead;
const int Size= 115000;
char Buffer[Size+1];
HRESULT hr = m_pStream->Read(Buffer, Size, &CbRead );
}
You can do it like this (you should define the stream type!)
HRESULT AMEPreviewHandler:: CreateHtmlPreview(stream)
{
ULONG CbRead;
const int Size= 115000;
char Buffer[Size+1];
HRESULT hr = stream->Read(Buffer, Size, &CbRead );
}
And call it like this
CreateHtmlPreview(m_pStream);

Answer 4

DoctorLove i have solved this problem actually the code by idea of accesing the non static varible using this parameter- the problem was i had not initialized the instance in WM_INITDIALOG now i donze like this-
case WM_INITDIALOG:
{
instance = (AMEPreviewHandler*)lParam;
instance->m_pStream;
return0;
}
and it works fine.