To set the range (minimum and maximum positions) for the slider in a slider control use the following function:

void CSliderCtrl::SetRange( int nMin, int nMax, BOOL bRedraw = FALSE );

Parameters:

nMin   Minimum position for the slider.

nMax   Maximum position for the slider.

bRedraw   The redraw flag. If this parameter is TRUE, the slider is redrawn after the range is set; otherwise the slider is not redrawn.

To retrieve the maximum and minimum positions for the slider in a slider control use the next function. It copies the values into the integers referenced by nMin and nMax.

void CSliderCtrl::GetRange( int& nMin, int& nMax ) const;

Here: nMin   Reference to an integer that receives the minimum position; nMax   Reference to an integer that receives the maximum position.

3. The working with progress bar

A progress bar is a window that an application can use to indicate the progress of a lengthy operation. It consists of a rectangle that is gradually filled, from left to right, with the system highlight color as an operation progresses.

Pic. 6.1 Progress bar.

You can use the progress control to indicate the progress of a lengthy operation. It is a rectangle that is gradually filled, from left to right, with the system highlight color as the operation progresses.

The progress control is represented in MFC by class CProgressCtrl.

You construct a CProgressCtrl object in two steps. First call the constructor, which creates the CProgressCtrl object; then call Create, which creates the progress bar control.

BOOL CProgressCtrl::Create(DWORD dwStyle, const RECT& rect, CWnd* pParentWnd, UINT nID );

Here are:

dwStyle   Specifies the progress bar control's style. Apply any combination of window styles to the control.

rect   Specifies the progress bar control's size and position. It can be either a CRect object or a RECT structure

pParentWnd   Specifies the progress bar control's parent window, usually a CDialog. It must not be NULL.

nID   Specifies the progress bar control's ID.

The basic settings for the progress control (CProgressCtrl) are the range and current position. The range represents the entire duration of the operation. The current position represents the progress that your application has made toward completing the operation. Any changes to the range or position causes the progress control to redraw itself.

By default, the range is set to 0 – 100, and the initial position is set to 0. To change the range of the progress control, use the SetRange member function. To set the position, use SetPos.

The functions to work with Progress bar

The SetRange() function sets the upper and lower limits of the progress bar control's range and redraws the bar to reflect the new ranges.

void CProgressCtrl::SetRange( int nLower, int nUpper );

nLower   Specifies the lower limit of the range (default is zero).

nUpper   Specifies the upper limit of the range (default is 100).

SetPos() function sets the progress bar control's current position as specified by nPos and redraws the bar to reflect the new position.

int CProgressBar::SetPos( int nPos );

Here nPos   New position of the progress bar control.

CProgressCtrl::StepIt( ); advances the current position for a progress bar control by the step increment (usually 10) and redraws the bar to reflect the new position. That step can be changes by SeyStep() function.

The example program to work with spin, slider and progress bar

In our example, that considering control elements are located in the dialog window. So their initiation is in the InitDialog() function. In the Listing 6.2 you can see it.

Listing 6.2. The spin, slider and progress bar initiation

BOOL CSDialog::OnInitDialog()

{RECT r; int i;

int parts[NUMPARTS];

r.left=r.top=r.right=r.bottom=0;

CDialog::OnInitDialog();

GetClientRect(&r);

m_Spin.Create(WS_VISIBLE | WS_CHILD | WS_BORDER | UDS_SETBUDDYINT | UDS_ALIGNRIGHT, r,this,IDC_SPIN1);

slay=(CSliderCtrl*)GetDlgItem(IDC_SLIDER1);

bt1=(CButton*)GetDlgItem(IDC_BUTTON1);

edd2=(CEdit*)GetDlgItem(IDC_EDIT1);

bt2=(CButton*)GetDlgItem(IDC_BUTTON2);

pc=(CProgressCtrl*)GetDlgItem(IDC_PROGRESS1);

m_Spin.SetBuddy(GetDlgItem(IDC_EDIT2));

m_Spin.SetRange(0,100);

m_Spin.SetPos(5);

slay->SetRange(0,100);

slay->SetPos(15);

return TRUE;

}

The listings of handlers on horizontal and vertical scrolling are on the Listing 6.3. The results are the next: the slider settings by horizontal scrolling are influences on the spin and progress bar, which are changing their selves. The vertical scrolling has influence on the spin parameters and progress bar. The selection of element is provided by corresponding test of objects (see SB testing in every case).

Listing 6.3. The horizontal and vertical handlers and their using for spin, progress bar and slider.

void CSDialog::OnHScroll(UINT SBCode, UINT Pos, CScrollBar * SB)

{if(SB==(CScrollBar *)slay)

{m_Spin.SetPos(slay->GetPos());

pc->SetPos(slay->GetPos());

char str3[40];

wsprintf(str3,"Slider position %d",slay->GetPos());

m_Status.SetText(str3,1,0);

}}

void CSDialog::OnVScroll(UINT SBCode, UINT Pos, CScrollBar * SB)

{if(SB=(CScrollBar *)&m_Spin)

{slay->SetPos(m_Spin.GetPos());

pc->SetPos(m_Spin.GetPos());

char str3[40];

wsprintf(str3,"Spin position %d",m_Spin.GetPos());

}}