Computer Programming Concepts and Visual Basic David I. Schneider

SOLUTION:
Object Property Setting
frmCircles BorderStyle 0-None
cmdMove Caption Move and Show Circle
cmdQuit Caption Quit
‘Class module for CCircle
Private m_x As Integer ‘Dist from center of circle to left side of form
Private m_y As Integer ‘Distance from center of circle to top of form
Private m_r As Single ‘Radius of circle
Private Sub Class_Initialize()
‘Set the initial center of the circle to the upper
‘left corner of the form and set its radius to 500.
m_x = 0
m_y = 0
m_r = 500
End Sub
Public Property Get Xcoord()
As Integer Xcoord = m_x
End Property
Public Property Let Xcoord(ByVal vNewValue As Integer)
m_x = vNewValue
End Property
Public Property Get Ycoord() As Integer
Ycoord = m_y
End Property
Public Property Let Ycoord(ByVal vNewValue As Integer)
m_y = vNewValue
End Property
Public Sub Show()
‘Display the circle.
‘See discussion of Circle method in Section 10.4.
frmCircles.Circle (m_x, m_y), m_r
End Sub
Public Sub Move(Dist)
‘Move the center of the circle Dist twips to the right
‘and Dist twips down.
m_x = m_x + Dist
m_y = m_y + Dist
Call Show
Classes and Objects 363