2. Projects Using  Intrinsic and Professional ActiveX Controls(1)

1. Project using the Timer Control:

A digital clock is a very simple but very useful application involving the timer control.    This project requires a timer and two labels.    The running time will be displayed in one label and the current date will be displayed in the other label.  Timer is an Iintrinsic ActiveX control and so is already present in the Tool Box.   Drag one timer and two label controls  into the form.    Give the labels appropriate size, font and border and set their caption property blank.    Set the timer interval property as 1000(one second) and the Enabled property as True.   The project at the design time looks as in the figure 4.

 
                                                Figure 4

Entering the Event Codes:

Open the code window by double clicking the Timer control  and enter the code.  

Private Sub Timer1_Timer()

If Label1.Caption <> CStr(Time) Then

Label1.Caption = Date

Label2.Caption = Time

End If

End Sub

Running the Project:

Select Start from the Run Menu.   The clock will begin to run.   The current date will be displayed in the other label. The run mode window is as shown in the figure 5.    Another important point you notice is that the timer control does not appear in the run mode,  and is invisible, but works only from behind.

                            Figure 5

 Building  BarChart Project:

Bar Charts are very useful for displaying business data, say product sales versus years.   VB has an ActiveX control named Microsoft Chart Control, to draw  two dimensional and three dimensional bar charts.

Controls used in this project:

The MS Chart control is brought into the Toolbox from the component dialog box.  If it is not available in the dialog box, click the browse button and select the same from the control files directory.  The MSChart icon will appear in the tool box.   It must be placed in a bitmap container. So a picture box  control is first drawn into the form.   Then the MSChart control is placed inside the picture box.   Then a command button is placed in the form.   It is given the caption and name as ‘setchart’.   The design window will look as shown in the figure 6.   The code window is opened by double clicking the setchart button and the code is entered as shown in the figure 6a.   Save the form as chartfrm and the project as chartprj.   Select start from the Run menu.   You will have to enter 9 data values in response to prompts.

Private Sub setchart_Click()

Dim i, j, k

MSChart1.RowCount = 3

MSChart1.ColumnCount = 3

MSChart1.chartType = VtChChartType2dBar

k = 1996

For i = 1 To 3

For j = 1 To 3

MSChart1.Row = i

MSChart1.Column = j

MSChart1.RowLabel = k

MSChart1.Data = InputBox("enter values for row " & i & " column " & j)

Next j

k = k + 1

Next i

End Sub

  Figure 6a

 
                                                Figure 6

                                                        Figure 7