C / C++ / MFC

21-Dec-09 23:49

After converting project from VC6.0 to VS2008,while running application it shows the following error

Unhandled exception at 0x787ac40c (mfc90d.dll) in CS3OperatorStation.exe: 0xC0000005: Access violation reading location 0x00000020.

When i debug it,i got this error in this particular line

void tSendActiveData()
{
while(1)
{
AfxGetMainWnd()->SendMessage(WM_COMMAND,ID_SENDACTIVEDATA,NULL); Sleep(500);
}
}
tSendActiveData is a thread.
I want to invoke this fucntion in this thread.thts why im using it.

Its working fine in VC6.0 version.

Anu

CPallini22-Dec-09 0:11

CPallini

22-Dec-09 0:11

You shouldn't do this. You should post a message to the main thread, using global namespace's PostMessage [^] with target the main window handle (you may pass it to the worker thread).
See this article [^] on how to use worker threads (read carefully the "Worker Threads and the GUI IV: AfxGetMainWnd" section).
Smile | :)

KingsGambit22-Dec-09 0:17

KingsGambit

22-Dec-09 0:17

Please check the return value of AfxGetMainWnd(). This function is supposed to return the main windows associated with the thread. As your thread does not have a window, the return value might be zero.

Maximilien22-Dec-09 0:22

Maximilien

22-Dec-09 0:22

Me think that AfxGetMainWnd() will return the window of the thread, not of the main application.

Pass a pointer of your main application window to your thread.

Max.

This signature was proudly tested on animals.

Anu_Bala22-Dec-09 0:48

22-Dec-09 0:48

How can i do that?

Anu

sh_read: Undeclared identifier

CPallini22-Dec-09 1:35

CPallini

22-Dec-09 1:35

Hint: the thread function has a parameter... Big Grin | :-D

Anu_Bala21-Dec-09 22:37

Re: sh_read: Undeclared identifier

21-Dec-09 22:37

Now im converting VC+.0 project in to VS2008 version.
It shows error on line
RFile.open(FName,ios::app,filebuf::sh_read);

as sh_read: Undeclared identifier

I included #include<fstream>,Using Namespace std;

But no use.It contniously show this error.
i declared RFile in header file as
class StreamOut : public ofstream
{
public:
StreamOut()
{
}
};
StreamOut RFile;

Im using RFile to Write also as
RFile.write(PageNo,2);
.
.
But it shows error on sh-read.
Anyother way to do this?

Anu

KingsGambit21-Dec-09 23:06

KingsGambit

21-Dec-09 23:06

Did you forget to mention the namespace std?

Re: sh_read: Undeclared identifier

Anu_Bala21-Dec-09 23:12

21-Dec-09 23:12

Yes, i included.
Now i change the fucntion as follow
RFile.open(FName,ios::app);

Now i doenot show error.I dont know its correct or not.

Anu

error C2487

Nandu_77b21-Dec-09 22:33

Nandu_77b

21-Dec-09 22:33

error C2487: 'CSingleton<T>::ms_pSingleton' : member of dll interface class may not be declared with dll interface

When I try to compile the below code in VS2008 above is the error. I am not sure hw to fix this, as the class is not exported (i am getting this error even when i try to export the member alone).

So please suggest me a better solution.

template <typename T>
class CSingleton
{
private:
ExportSlotCoreLib static T* ms_pSingleton;

CSingleton(const CSingleton&);

protected:
CSingleton() {
//assert(ms_pSingleton == NULL);
int offset = (char*)(T*)1 - (char*)(CSingleton <T>*)(T*)1;
ms_pSingleton = reinterpret_cast<T*>(reinterpret_cast<char*>(this) + offset);
}

~CSingleton() {
//assert(ms_pSingleton != NULL);
ms_pSingleton = NULL;
}

public:
static T& GetSingleton() {
return (T&)*ms_pSingleton;
}

static T* GetSingletonPtr() {
return ms_pSingleton;
}

};

Thanks,
Nandu

Re: error C2487

KingsGambit21-Dec-09 23:10

KingsGambit

21-Dec-09 23:10

Can you remove ExportSlotCoreLib from pSingleton declaration and try?

Re-Mssql question

MsmVc21-Dec-09 20:28

21-Dec-09 20:28

Hi All
USE database command is not working for me.I was asking same question in last week but still i have no solution then i ask one more time.Plz help me

connection code is here

CString str1="",str2="",str3="";
	HRESULT hr;
	if SUCCEEDED(hr = CoInitialize(NULL))
	{
		try
		{
		
			if (SUCCEEDED(spSQLServer.CreateInstance(__uuidof(SQLServer2))))
			{
				try
				{
					HOST=(_bstr_t)m_MHOST;
				
					if(rad1.GetCheck())
					{
						spSQLServer->LoginSecure = TRUE;
						spSQLServer->Connect((_bstr_t)m_MHOST);
					}
					else
					{
						spSQLServer->LoginSecure = FALSE;
						spSQLServer->Connect((_bstr_t)m_MHOST,(_bstr_t)m_MUSR,(_bstr_t)m_MPWD);
					}
					
				
					
				
				}
				catch(_com_error pCE)
				{
				
					str2.Format(_T("%s"),
					MessageBox(str2,"Message");
					return TRUE;
				}
			}
			else
			{
				str3.Format(_T("Unable to create the SQL Server object.\n"));
		
			}
		}
		catch(_com_error pCE)
		{
			str2.Format(_T("\n%s Error: %ld\r\n%s\r\n%s\r\n"),
				(TCHAR*)pCE.Source(),
				pCE.Error(),
				(TCHAR*)pCE.Description(),
				(TCHAR*)pCE.ErrorMessage());
		}

	
	}
	else
	{
		str2.Format(_T("Call to CoInitialize failed.\n"));
	}

Use database command code is here

QueryResultsPtr Qry;
_SQLServer2Ptr spSQLServer;
CString udata="use 'databasename'";
//(databasename is like master ,use create database)
Qry=spSQLServer->ExecuteWithResults((_bstr_t)udata,(LONG)udata.GetLength());

Select command is running fine like this

CString sel="select * from 'Database name'.dbo.'Table Name'"
Qry=spSQLServer->ExecuteWithResults((_bstr_t)sel,(LONG)sel.GetLength());

Can any one help me why

USE 'Database name'

not working.
Plz help me

Code-o-mat21-Dec-09 21:00

Code-o-mat

21-Dec-09 21:00

MsmVc wrote:
USE database command is not working for me.

-explain, does it give an error, does it simply not do what is expected (e.g: it completes successfully but does not seem to make any change), how do you know it fails?

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Sometimes you just have to hate coding to do it well. <

MsmVc21-Dec-09 21:05

21-Dec-09 21:05

it completes successfully but does not seem to make any change.
After use database command then i check through this command.

SELECT DB_NAME() AS DataBaseName

it's always show "Master" database name.

Code-o-mat21-Dec-09 21:13

Code-o-mat

21-Dec-09 21:13

Let's experiment, try this:

CString udata="use \"databasename\"";
//(databasename is like master ,use create database)
Qry=spSQLServer->ExecuteWithResults((_bstr_t)udata,(LONG)udata.GetLength());

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Sometimes you just have to hate coding to do it well. <

MsmVc21-Dec-09 21:17

21-Dec-09 21:17

thanks ,i use code which is given by you.But i got error

Microsoft SQL-DMO (ODBC SQLState: 42000) Error: -2147221402 [Microsoft][ODBC SQL Server Driver][SQL Server]Incorrect syntax near 'databasename'. Invalid STDGMEDIUM structure

Code-o-mat21-Dec-09 22:01

Code-o-mat

21-Dec-09 22:01

How about CString udata="use databasename"; ? Btw do you know that -according to msdn- Microsoft recommends not using sql-dmo in newer products because it will be removed by them?

> The problem with computers is that they do what you tell them to do and not what you want them to do. <
> Sometimes you just have to hate coding to do it well. <

MsmVc21-Dec-09 22:04