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Visual C++ 6.0 21天自学教程 一本适合初学和对c++有一定基础的人学习的好书

<PRE> 1: void CMouseDlg::OnMouseMove(UINT nFlags, CPoint point)
 2: {
 3:     // TODO: Add your message handler code here and/or call default
 4:
 5:     ///////////////////////
 6:     // MY CODE STARTS HERE
 7:     ///////////////////////
 8:
 9:         // Check to see if the left mouse button is down
10:     if ((nFlags &amp; MK_LBUTTON) == MK_LBUTTON)
11:     {
12:         // Get the Device Context
13:         CClientDC dc(this);
14:
15:         // Create a new pen
16:         CPen lpen(PS_SOLID, 16, RGB(255, 0, 0));
17:
18:         // Use the new pen
19:         dc.SelectObject(&amp;lpen);
20:
21:         // Draw a line from the previous point to the current point
22:         dc.MoveTo(m_iPrevX, m_iPrevY);
23:         dc.LineTo(point.x, point.y);
24: 
25:         // Save the current point as the previous point
26:         m_iPrevX = point.x;
27:         m_iPrevY = point.y;
28:     }
29:
30:     // Check to see if the right mouse button is down
31:     if ((nFlags &amp; MK_RBUTTON) == MK_RBUTTON)
32:     {
33:         // Get the Device Context
34:         CClientDC rdc(this);
35:
36:         // Create a new pen
37:         CPen rpen(PS_SOLID, 16, RGB(0, 0, 255));
38: 
39:         // Use the new pen
40:         rdc.SelectObject(&amp;rpen);
41: 
42:         // Draw a line from the previous point to the current point
43:         rdc.MoveTo(m_iPrevX, m_iPrevY);
44:         rdc.LineTo(point.x, point.y);
45: 
46:         // Save the current point as the previous point
47:         m_iPrevX = point.x;
48:         m_iPrevY = point.y;
49:     }
50:
51:     ///////////////////////
52:     // MY CODE ENDS HERE
53:     ///////////////////////
54:
55:     CDialog::OnMouseMove(nFlags, point);
</PRE>
<PRE>56: }</PRE>

<DL>
	<DT></DT>
	<DD><B>2. </B>Extend the OnKeyDown function to add some of the following standard
	cursors:
	<P>
</DL>


<UL>
	<LI>IDC_CROSS
	<P>
	<LI>IDC_UPARROW
	<P>
	<LI>IDC_SIZEALL
	<P>
	<LI>IDC_SIZENWSE
	<P>
	<LI>IDC_SIZENESW
	<P>
	<LI>IDC_SIZEWE
	<P>
	<LI>IDC_SIZENS
	<P>
	<LI>IDC_NO
	<P>
	<LI>IDC_APPSTARTING
	<P>
	<LI>IDC_HELP
</UL>


<DL>
	<DT></DT>
	<DD>Your modified OnKeyDown function can look something like the following:
	<P>
</DL>

<PRE>void CMouseDlg::OnKeyDown(UINT nChar, UINT nRepCnt, UINT nFlags)
{
    // TODO: Add your message handler code here and/or call default
    ///////////////////////
    // MY CODE STARTS HERE
    ///////////////////////
    char lsChar;        // The current character being pressed
    HCURSOR lhCursor;    // The handle to the cursor to be displayed
    // Convert the key pressed to a character
    lsChar = char(nChar);
    // Is the character &quot;A&quot;
    if (lsChar == `A')
    {
        // Load the arrow cursor
        lhCursor = AfxGetApp()-&gt;LoadStandardCursor(IDC_ARROW);
        // Set the cursor flag
        m_bCursor = TRUE;
        // Set the screen cursor
        SetCursor(lhCursor);
    }
    // Is the character &quot;B&quot;
    if (lsChar == `B')
    {
        // Load the I beam cursor
        lhCursor = AfxGetApp()-&gt;LoadStandardCursor(IDC_IBEAM);
        // Set the cursor flag
        m_bCursor = TRUE;
        // Set the screen cursor
        SetCursor(lhCursor);
    }
    // Is the character &quot;C&quot;
    if (lsChar == `C')
    {
        // Load the hourglass cursor
        lhCursor = AfxGetApp()-&gt;LoadStandardCursor(IDC_WAIT);
        // Set the cursor flag
        m_bCursor = TRUE;
        // Set the screen cursor
        SetCursor(lhCursor);
    }
    // Is the character &quot;D&quot;
    if (lsChar == `D')
    {
        // Load the cross hair cursor
        lhCursor = AfxGetApp()-&gt;LoadStandardCursor(IDC_CROSS);
        // Set the cursor flag
        m_bCursor = TRUE;
        // Set the screen cursor
        SetCursor(lhCursor);
    }
    // Is the character &quot;E&quot;
    if (lsChar == `E')
    {
        // Load the up arrow cursor
        lhCursor = AfxGetApp()-&gt;LoadStandardCursor(IDC_UPARROW);
        // Set the cursor flag
        m_bCursor = TRUE;
        // Set the screen cursor
        SetCursor(lhCursor);
    }
    // Is the character &quot;F&quot;
    if (lsChar == `F')
    {
        // Load the size cursor
        lhCursor = AfxGetApp()-&gt;LoadStandardCursor(IDC_SIZEALL);
        // Set the cursor flag
        m_bCursor = TRUE;
        // Set the screen cursor
        SetCursor(lhCursor);
    }
    // Is the character &quot;G&quot;
    if (lsChar == `G')
    {
        // Load the up/right-down/left size cursor
        lhCursor = AfxGetApp()-&gt;LoadStandardCursor(IDC_SIZENWSE);
        // Set the cursor flag
        m_bCursor = TRUE;
        // Set the screen cursor
        SetCursor(lhCursor);
    }
    // Is the character &quot;H&quot;
    if (lsChar == `H')
    {
        // Load the up/left-down/right size cursor
        lhCursor = AfxGetApp()-&gt;LoadStandardCursor(IDC_SIZENESW);
        // Set the cursor flag
        m_bCursor = TRUE;
        // Set the screen cursor
        SetCursor(lhCursor);
    }
    // Is the character &quot;I&quot;
    if (lsChar == `I')
    {
        // Load the left-right size cursor
        lhCursor = AfxGetApp()-&gt;LoadStandardCursor(IDC_SIZEWE);
        // Set the cursor flag
        m_bCursor = TRUE;
        // Set the screen cursor
        SetCursor(lhCursor);
    }
    // Is the character &quot;J&quot;
    if (lsChar == `J')
    {
        // Load the up-down size cursor
        lhCursor = AfxGetApp()-&gt;LoadStandardCursor(IDC_SIZENS);
        // Set the cursor flag
        m_bCursor = TRUE;
        // Set the screen cursor
        SetCursor(lhCursor);
    }
    if (lsChar == `K')
    {
        // Load the no cursor
        lhCursor = AfxGetApp()-&gt;LoadStandardCursor(IDC_NO);
        // Set the cursor flag
        m_bCursor = TRUE;
        // Set the screen cursor
        SetCursor(lhCursor);
    }
    if (lsChar == `L')
    {
        // Load the app starting cursor
        lhCursor = AfxGetApp()-&gt;LoadStandardCursor(IDC_APPSTARTING);
        // Set the cursor flag
        m_bCursor = TRUE;
        // Set the screen cursor
        SetCursor(lhCursor);
    }
    if (lsChar == `M')
    {
        // Load the help cursor
        lhCursor = AfxGetApp()-&gt;LoadStandardCursor(IDC_HELP);
        // Set the cursor flag
        m_bCursor = TRUE;
        // Set the screen cursor
        SetCursor(lhCursor);
    }
    // Is the character &quot;X&quot;
    if (lsChar == `X')
    {
        // Load the arrow cursor
        lhCursor = AfxGetApp()-&gt;LoadStandardCursor(IDC_ARROW);
        // Set the cursor flag
        m_bCursor = TRUE;
        // Set the screen cursor
        SetCursor(lhCursor);
        // Exit the application
        OnOK();
    }
    ///////////////////////
    // MY CODE ENDS HERE
    ///////////////////////
    CDialog::OnKeyDown(nChar, nRepCnt, nFlags);
</PRE>
<PRE>}
</PRE>
<H2><A NAME="Heading10"></A>Day 4</H2>
<H3>Quiz</H3>

<DL>
	<DT></DT>
	<DD><B>1. </B>What did you accomplish by adding the two timer IDs to the resource
	symbols?
	<P>
	<DT></DT>
	<DD>You defined the two IDs so that they were available as constants throughout the
	application.
	<P>
	<DT></DT>
	<DD><B>2. </B>What is another way to add these two IDs to the application?
	<P>
	<DT></DT>
	<DD>Add them as #define constants in the class header file (Day2Dlg.h), as follows:
	<P>
</DL>

<PRE>/////////////////////////////////////////////////////////////////////// CTimersDlg dialog
#define ID_CLOCK_TIMER 1
#define ID_COUNT_TIMER 2
class CTimersDlg : public CDialog
{
.
.
</PRE>
<PRE>.
</PRE>

<DL>
	<DT></DT>
	<DD><B>3. </B>How can you tell two timers apart in the OnTimer function?
	<P>
	<DT></DT>
	<DD>You use the timer ID to determine which timer triggered the event.
	<P>
	<DT></DT>
	<DD><B>4. </B>How many timer events does your application receive if the timer is
	set for one second and your application has been busy for one minute, preventing
	it from receiving any timer event messages?
	<P>
	<DT></DT>
	<DD>One.
	<P>
</DL>

<H2>Exercise</H2>
<P>Update your application so that when the counter timer is started, the clock timer
is reset to run at the same interval as the counter timer. When the counter timer
is stopped, return the clock timer to a one-second interval.</P>
<P>To change the interval at which a timer is running, you need to first stop the
timer and then restart it, as in Listing B.6.</P>
<P>
<H4>LISTING B.6. THE REVISED OnStarttime AND OnStoptimer FUNCTIONS.</H4>
<PRE> 1: void CTimersDlg::OnStarttime()
 2: {
 3:     // TODO: Add your control notification handler code here
 4: 
 5:     ///////////////////////
 6:     // MY CODE STARTS HERE
 7:     ///////////////////////
 8: 
 9:     // Update the variables
10:     UpdateData(TRUE);
11: 
12:     // Initialize the count
13:     m_iCount = 0;
14:     // Format the count for displaying
15:     m_sCount.Format(&quot;%d&quot;, m_iCount);
16: 
17:     // Update the dialog
18:     UpdateData(FALSE);
19:     // Start the timer
20:     SetTimer(ID_COUNT_TIMER, m_iInterval, NULL);
21: 
22:     // Stop the clock timer
23:     KillTimer(ID_CLOCK_TIMER);
24:     // Restart the clock timer with the counter interval
25:     SetTimer(ID_CLOCK_TIMER, m_iInterval, NULL);
26: 
27:     // Enable the Stop Timer button
28:     m_cStopTime.EnableWindow(TRUE);
29:     // Disable the Start Timer button
30:     m_cStartTime.EnableWindow(FALSE);
31: 
32:     ///////////////////////
33:     // MY CODE ENDS HERE
34:     ///////////////////////
35: }
36: 
37: void CTimersDlg::OnStoptimer()
38: {
39:     // TODO: Add your control notification handler code here
40: 
41:     ///////////////////////
42:     // MY CODE STARTS HERE
43:     ///////////////////////
44: 
45:     // Stop the timer
46:     KillTimer(ID_COUNT_TIMER);
47: 
48:     // Stop the clock timer
49:     KillTimer(ID_CLOCK_TIMER);
50:     // Restart the clock timer with 1 second interval
51:     SetTimer(ID_CLOCK_TIMER, 1000, NULL);
52: 
53:     // Disable the Stop Timer button
54:     m_cStopTime.EnableWindow(FALSE);
55:     // Enable the Start Timer button
56:     m_cStartTime.EnableWindow(TRUE);
57: 
58:     ///////////////////////
59:     // MY CODE ENDS HERE
60:     ///////////////////////
</PRE>
<PRE>61: }</PRE>
<P>
<H2><A NAME="Heading13"></A>Day 5</H2>
<H3>Quiz</H3>

<DL>
	<DT></DT>
	<DD><B>1. </B>What are the possible return codes that your application might receive
	from the MessageBox function call when you specify the MB_RETRYCANCEL button combination?
	<P>
	<DT></DT>
	<DD>IDRETRY and IDCANCEL.
	<P>
	<DT></DT>
	<DD><B>2. </B>What are the common dialogs that are built into the Windows operating
	systems that are defined as MFC classes?
	<P>
	<DT></DT>
	<DD>The common Windows dialogs that are defined as MFC classes are
	<P>
</DL>


<UL>
	<LI>File selection
	<P>
	<LI>Font selection
	<P>
	<LI>Color selection
	<P>
	<LI>Page setup for printing
	<P>
	<LI>Printing
	<P>
	<LI>Find and replace
</UL>


<DL>
	<DT></DT>
	<DD><B>3. </B>What is the difference between a modal dialog and a modeless dialog?
	<P>
	<DT></DT>
	<DD>A modal dialog stops all application processing until the user responds to the
	dialog. A modeless dialog allows the user to continue working with the rest of the
	application while the dialog is open for use.
	<P>
	<DD><B>4. </B>How can you display a File Save dialog for the user instead of the
	File Open dialog that you did have in your application?
	<DT></DT>
	<DD>In the class instance variable declaration, pass FALSE instead of TRUE. This
	makes the variable declaration look like this:
	<P>
</DL>

<PRE>CFileDialog m_ldFile(FALSE);
</PRE>

<DL>
	<DT></DT>
	<DD><B>5. </B>Why did you not need to create any functions and add any code to your
	custom dialog?
	<P>
	<DT></DT>
	<DD>The only functionality that was needed on the custom dialog was calling UpdateData
	before closing the dialog. Because the OK and Cancel buttons were never deleted from
	the dialog, the OK button automatically performed this functionality.
	<P>
</DL>

<H3>Exercises</H3>

<DL>
	<DT></DT>
	<DD><B>1. </B>Modify your application so that it includes the directory with the
	filename in the application. (Hint: The GetFileName function returns the path and
	filename that was selected in the File Open dialog.)
	<P>
	<DT></DT>
	<DD>Modify the OnFileopen function as follows:
	<P>
</DL>

<PRE>void CDialogsDlg::OnFileopen() 
{
    // TODO: Add your control notification handler code here
    ///////////////////////
    // MY CODE STARTS HERE