|
5.
Projects using Intrinsic and Professional ActiveX Controls(4)
2.
Project
for
Drawing a
Piechart:
The
Piechart
application
uses
the
Circle
method
to
draw
pie
charts
with
connected
arcs. Because
a
connected
arc
is a
closed
shape,
it
can
also
be
filled
with
a
pattern
or a
solid
color
as
specified
by
the
FillStyle
and
FillColor
properties.
The
program
generates
10
random
numbers
in
the
range
20
to
100,
stores
them
in
the
piedata()
array,
and
then
calculates
the
arc
that
corresponds
to
each
number. Because
the
total
must
be a
full
circle,
each
element
of
the
piechart()
array
corresponds
to
an
arc
of
2*pi*piedata()/total. Each
slice’s
starting
angle
is
the
ending
angle
of
the
previous
slice,
and
its
ending
angle
is
the
starting
angle
plus
the
angle
corresponding
to
the
element
in
the
piedata
array.
Drag
two
check
boxes
and
three
command
buttons
from
the
Toolbox,
caption
them,
size
them
and
position
them
as
shown
in
the
figure
3.
Open
the
code
window
of
the
command
buttons
and
enter
the
codes
as
shown
in
the
figure
4a.. Save
and
run
the
application. The
run
mode
window
will
appear
as
in
the
figure
4.
Figure
3
Private
Sub
Command1_Click()
Dim
pieData(10)
As
Integer
Form1.Cls
For
i =
0 To
9
pieData(i)
= 20
+
Rnd()
*
100
Total
=
Total
+
pieData(i)
Next
Form1.DrawWidth
= 3
For
i =
0 To
9
arc1
=
arc2
arc2
=
arc1
+
6.28
*
pieData(i)
/
Total
If
Check1.Value
Then
Form1.FillStyle
= 2
+ (i
Mod
5)
Else
Form1.FillStyle
= 0
End
If
If
Check2.Value
Then
Form1.FillColor
=
QBColor(8
+ (i
Mod
6))
Else
Form1.FillColor
=
QBColor(9)
End
If
Form1.Circle
(Form1.ScaleWidth
/ 2,
Form1.ScaleHeight
/
2),
Form1.ScaleHeight
/
2.5,
,
-arc1,
-arc2
Next
End
Sub
Private
Sub
Command2_Click()
End
End
Sub
Private
Sub
Command3_Click()
Form1.Cls
End
Sub
Figure
4a
Figure
4
   |
