C / C++ / MFC

LionAM wrote:

It is passed to the library. However, the function fails with an access violation when the dll tries to change a member of the colorspace struct. The problem is that fz_device_bgr has different values inside the dll and inside the sample (where it is undefinded?).

class CMyClass
{
public:
    CString m_DefaultErrorExt;
    CString & m_sErrorExt;

public:
    CMyClass(void) : sErrorExt(DefaultErrorExt) {}
    CMyClass(CString & ExternError) : sErrorExt(ExternError) {}
};

BOOL CMyClass::Execute(LPCTSTR lpszParam1, CString& sError);

class MyClass
{
public:
  bool execute()
  {
    try
    {
      // ...
      throw exception("Testing testing");
      return true;
    }
    catch(exception& e)
    {
      m_lastError = e.what();
      return false;
    } 
  }
  CString& lastError()
  {
    return m_lastError;
  }
private:
  CString m_lastError;
};

void tryIt()
{
  MyClass c;
  if( c.execute() )
    cout << "All well" << endl;
  else
    cout << "MyClass.execute failed: " << c.lastError().GetString() << endl;
}

CMyClass
{
    BOOL Execute(LPCTSTR lpszSQL,CString& sError);
}

BOOL CMyClass::Execute(LPCTSTR lpszSQL,CString& sError)
{
    try
    {
        throw ....
    }
    catch(CException* e)
    {
        e->GetErrorMessage(sError.GetBufer(255),255);
        sError->ReleaseBuffer();
        e->Delete();
    }
}

CMyClass obj;
CString sError;
if(! obj.Execute(_T("SELECT * FROM mytable"),sError))
{
    MessageBox(sError);
    return;
}

pix_programmer wrote:

static MenuSettings mSettings;

MenuSettings mSettings;

extern MenuSettings mSettings;

class Derived : public Base
{
  int data;
public:
      Derived() { data = 100;}
      void foo1() { }
      void foo3() { cout << data << endl;}
} ;

msr_codeproject wrote:

1) How it is possible to call foo3() of derived class.

msr_codeproject wrote:

I am not able to understand this. Please explain.

Derived * d = (Derived*)new Base() ;

Derived * d = new Derived;