Advanced MFC Programming

Chapter 5. Common Controls
Custom Resource
The AVI data can be included in the application as a resource. However, Developer Studio does not
support this kind of resource directly. So we have to treat it as a custom resource. We can create AVI
resource from a “*.avi” file through following steps: 1) Execute Insert | Resource command, then click
“Import” button from the “Insert resource” dialog box. 2) From the popped up “File open” dialog box,
browse and select a “*.avi” file and open it (we can use “5.17\CCtl\search.avi” or any other “*.avi” file for
this purpose). 3) When we are asked to provide the resource type, input “AVI”. 4) Name the resource ID as
IDR_AVI.
Sample Implementation
In the dialog box’s initialization stage, we need to initialize the animate control, progress control and
set timer as follows:
……
BOOL CCCtlDlg::OnInitDialog()
{
}
ASSERT(m_animateCtrl.Open(IDR_AVI));
ASSERT(m_animateCtrl.Play(0, -1, -1));
m_progressCtrl.SetRange(0, 50);
m_progressCtrl.SetStep(2);
SetTimer(PROGRESS_CTRL, 500, NULL);
return TRUE;
First, function CAnimateCtrl::Open(…) is called to open the animation resource, then function
CAnimateCtrl::Play(…) is called to play the AVI data. When doing this, we pass 0 to its first parameter
and -1 to the second parameter, this will let the animation be played from the first frame to the last frame.
The third parameter is also -1, this means the animation will be played again and again without being
stopped.
Then we initialize the range of progress control from 0 to 50, incremental step 2, and a timer with time
out period of 500 milliseconds is set.
Message WM_TIMER can be handled by adding message handlers, this can be easily implemented
through using Class Wizard. In the sample, this member function is implemented as follows:
void CCCtlDlg::OnTimer(UINT nIDEvent)
{
if(nIDEvent == PROGRESS_CTRL)
{
m_progressCtrl.StepIt();
}
CDialog::OnTimer(nIDEvent);
}
The only parameter of this function is nIDEvent, which indicates the ID of the timer that has just timed
out. If we have two or more timers set within the same window, by examining this ID we know which
timer has timed out. In the sample, when timer times out, we simply call function
CProgressCtrl::StepIt() to advance the progress bar one step forward.
Summary:
1) A spin control must work together with another control, which is called the “Buddy” of the spin
control. Usually the “Buddy” is an edit box, but it could be any other types of controls such as button
or static control.
2) To set buddy automatically, we must make sure that the buddy window is the previous window of the
spin control in Z-order.
1) The buddy can also be set by calling function CSpinButtonCtrl::SetBuddy(…).
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