Computer Science 275.001

Interaction Programming

Fall 2006

Visual Basic

Programming Assignment #1

Due: Thursday, August 31, 2006

(Due in drop-box by 1:00 PM)

(.exe file)

(zipped solution)

Your first VB2005 assignment in this course is designed to provide you with some practice with procedures, functions, conditionals, labels, and buttons. The single form in this application will provide a straightforward calendar implementation, displaying a single day at a time and allowing the user to adjust the day, month, and year of the displayed date forwards and backwards via buttons. In addition, the form will display the day of the week for the displayed date, as well as the name of the national holiday being displayed (if the date is a national holiday).
The form will have the structure displayed below:
 

Note that this design involves event handlers for seven buttons: an exit button and six previous/next buttons for the month, day, and year being displayed. In addition, an adjustment should only affect the time unit that is associated with a particular button (e.g., adding a day to New Year's Eve takes the user to December 1 of that same year, subtracting a month from a January date takes the user to December of that same year). Finally, any of ten national holidays are recognized by this application, with font colors switched from black to dark red whenever a holiday is displayed.

Required member functions in your form’s class include:

Ÿ Event handlers for loading the form and clicking each of the seven buttons.

Ÿ A sub-procedure for updating the date labels (called at the end of each event handler).

Ÿ A function that calculates the name of the current date’s holiday, returning an empty string if the date is not a holiday.

In addition, your class should have a data member to store the current date, as well as arrays storing the names of the months and the names of the days of the week.

Holiday Calculation

The ten national holidays that you should implement in your application are:

• New Year’s Day – January 1
• Martin Luther King, Jr., Day – the third Monday in January
• Presidents’ Day – the third Monday in February
• Memorial Day – the last Monday in May
• Independence Day – July 4
• Labor Day – the first Monday in September
• Columbus Day – the Monday nearest to October 12
• Veterans Day – November 11
• Thanksgiving Day – the fourth Thursday in November
• Christmas Day – December 25

For instance, to test for Presidents’ Day, check whether the month is February, and the day of the week is Monday, and the day of the month is between 15 and 21. Similarly, to check for Columbus Day, check whether the month is October, and the day of the week is Monday, and the day of the month is between 9 and 15.

The Visual Basic 2005 Date Class

To facilitate the implementation of this application, use the VB2005 Date class, which provides much of the functionality that you will require.

'The following code sets the variable up with the run-time date.

Dim CurrentDate As Date

CurrentDate = Now

'The following code sets the variable CurrentDay up with the numerical value of

'CurrentDate’s day (between 1 and the number of days in CurrentDate’s month).

Dim CurrentDay As Integer = CurrentDate.Day

'The following code sets the variable CurrentMonth up with the

'numerical value of CurrentDate’s month (between 1 and 12).

Dim CurrentMonth As Integer = CurrentDate.Month

'The following code sets the variable CurrentYear up

'with the numerical value of CurrentDate’s year.

Dim CurrentYear As Integer = CurrentDate.Year

'The following code sets the variable CurrentDayOfWeek up with the numerical value of

'CurrentDate’s day of the week (0 for Sunday, 1 for Monday, ..., 6 for Saturday).

Dim CurrentDayOfWeek As Integer = CurrentDate.DayOfWeek

CurrentDate = CurrentDate.AddDays(3) 'Advance the entire date 3 days.

CurrentDate = CurrentDate.AddDays(-2) 'Move the entire date back 2 days.

CurrentDate = CurrentDate.AddMonths(1) 'Advance the entire date 1 month.

CurrentDate = CurrentDate.AddMonths(-5) 'Move the entire date back 5 months.

CurrentDate = CurrentDate.AddYears(20) 'Advance the entire date 20 years.

CurrentDate = CurrentDate.AddYears(-4) 'Move the entire date back 4 years.

'The following code sets the variable CurrentDaysInMonth up with the numerical value

'of the number of days in CurrentDate’s month, given its month and year values.

Dim CurrentDaysInMonth As Integer = Date.DaysInMonth(CurrentDate.Year, CurrentDate.Month)

Remember that your entire project folder is due on your drop-box by 1:00 PM on Thursday, August 31, 2006.