(B) All Win32 API applications implement the "event-driven" paradigm with something called the
message loop. What Win32 API function is usually used to retrieve the next message in the program's
message loop? What information is contained in its parameters? What message should cause the loop
to terminate?

of the program?
 
 
 
 

3A. In a Win32 API application, what happens after the Windows operating system sends a
message back to the application's message loop?

  
  
  
  
  

4. Write some Visual C++ Win32 API code that will draw a red rectangle whose upper left-hand corner
is at x=100, y=200 on the window's client area and that has a width of 90 pixels and a height of 60
pixels whenever the right mouse button goes down. Assume the message that is sent to the window when
the button goes down is wMsg.
  
  
  
  
  
  

  
   
   

6. The following Visual C++ code is placed the view class of an MFC doc/view application:

  

(B) Exactly what will appear on the screen if the user glides the mouse horizontally over the window's
client area?
   
    

  
  
7A. In an MFC Single Document Interface application the Visual Studio Designer has been used to prepare
the template for a dialog box whose ID is IDD_CHOICE that contains a Listbox control whose ID is IDC_C
containing the CStrings "Choice 1" and "Choice 2".
  
Explain how you would use Visual Studio to prepare a dialog box class called CChoice based on the MFC
CDialog class that will encapsulate the dialog box in Part A.

  

  
    

7B. Assume you have declared a public CString variable called m_choice in the CChoice class and that you
have used the "Dialog Data Exchange (DDX)" mechanism of associating the m_choice variable with the
IDC_C Listbox control. The dialog box is to be invoked in response to the user clicking on a "Make Choice"
menu item on the main window. In the skeleton menu item handler below write some Visual C++ code that
will start the dialog box modally and display either a filled red square or circle centered in the middle of the client
area of the parent window, depending  whether the user chose "Choice 1" or "Choice 2" from the its list box
before clicking its "OK" button. ("Choice 1" means a square; "Choice 2" means a circle.) The radius of the
circle or the length of the side of the square should be 100 pixels. This handler function is defined in the class
derived from CView.

  
void CTextView::OnMakeChoice()
{
    // TODO: Add your command handler code here

 

 

 

 

 
   
}

    

8. A .NET Frmework C# class called Circ is supposed to encapsulate some functionality associated with
a circle. The class has a constructor, a private integer field called radius, and a public property called Rad
that provides controlled access to the radius field. It also has a public method called Circumference()
that is supposed to compute and return the circumference (length of the arc of the circle) of an instance
of Circ. The following is skeleton C# code for the Circumference() method:

public int Circumference()

   
  
  
}
 
(A) Write some C# code (not more than three lines each) that completes the bodies of the constructor and
the Circ( ) methods given above. Write your code in the spaces after the comments above.<>
  
(B) Write some C# code that will use this Circ class in a Windows Form in the following way: (1) create a
new instance of the Circ class called myCirc that has a radius of 50; (2) obtain and display the value of
myCirc's radius in the upper lefthand corner of the window's form; (3) change myCirc's radius to 100;
(4) compute the circumference of myCirc and display it and the new radius just underneath the display
of  the original radius. The two lines displayed should look something like the following:
 
The circle had a radius of 50 9. Assume the Form class of a .NET application has an event called SomeEv. The delegate for that
event has been defined as follows:
  
public delegate void SomeEvHandler(object objSender, EventArgs someEvArgs);
  
(A) Write a line of C# code that will add an event handler called MySomeEvHandler to the the Form's
SomeEv Event.
 
 
 
 

(B) Add some C# code to the skeleton MySomeEvHandler() code given below that will cause the
image stored in the file myPic.jpg to be displayed in the client area of the window. The upper lefthand
corner of the image should be 100 pixels in from the window's lefthand border and 20 pixels down
from the top of the window's client area. (You may assume that the file myPic.jpg is in the same
directory as the program's executable file.)

private void MySomeEvHandler(object s, EventArgs e)

     // Your code goes here
 
 
 
 
 

}
   
 

     // Your code goes here

    
   
 
 
   

11B. Assume the handler function for the timer event is called timer1_tick(...). Write some C# code for this
handler that will display your name at some random location between (x=0, y=0) and (x=200, y=100)
on the client area of the window every time the timer times out.