Advanced MFC Programming

Chapter 9. Font
Frame border
is gray
Figure 9-4. Set frame border to gray
Variable m_perBar will be used to implement percentange bar, and m_nPercent will be used to record
the current position of the percentage bar.
Variable m_nPercent is initialized in the constructor:
CProgDlg::CProgDlg(CWnd* pParent /*=NULL*/)
: CDialog(CProgDlg::IDD, pParent)
{
//{{AFX_DATA_INIT(CProgDlg)
//}}AFX_DATA_INIT
m_nPercent=0;
}
In the sample, WM_INITDIALOG message handler is added to the application through using Class Wizard,
and funtion CProgDlg::OnInitDialog() is implemented as follows:
BOOL CProgDlg::OnInitDialog()
{
CDialog::OnInitDialog();
m_perBar.SubclassDlgItem(IDC_STATIC_PROG, this);
SetTimer(TIMER_ID, 100, NULL);
return TRUE;
}
Control IDC_STATIC_PROG is changed to a progress bar through implementing subclass, then a timer is
started to generate events that will be handled to advance the percentage bar.
To handle time out events, in the sample, a WM_TIMER message handler is added throgh using Class
Wizard. The corresponding member function CProgDlg::OnTimer(…) is implemented as follows:
void CProgDlg::OnTimer(UINT nIDEvent)
{
if(nIDEvent == TIMER_ID)
{
m_perBar.SetPercentage(m_nPercent++);
if(m_nPercent == 100)m_nPercent=0;
}
CDialog::OnTimer(nIDEvent);
}
If timer times out, we advance the percentage bar one step forward (1%); if the percentage bar reaches
100%, we reset it to 0%.
We must destroy timer when the application exits. The best place of doing this is when we receive
WM_DESTROY message. This message handler can also be added through using Class Wizard. In the sample,
the corresponding member function is implemented as follows:
void CProgDlg::OnDestroy()
{
CDialog::OnDestroy();
KillTimer(TIMER_ID);
}
For the purpose of testing the percentage bar, a new command Dialog | Progress is added to the
application, whose command ID is ID_DIALOG_PROGRESS. A WM_COMMAND message handler is added to class
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