Object-Oriented In-Class Assignment
Programming – VB Auto Center
The president of the Valley Boulevard (VB) Auto Center has asked you to build a system with a form like the one shown here. The project must separate the business logic for programming from the user interface.
Project Specifications and Requirements:
• Create a "class" named Sale. The Sale class must have properties for each of the purchase options, e.g.: stereo system, leather interior, computer navigation, standard, pearlized, and customized detailing. The Sale class must also have properties that will store the values that are typed into the two text boxes (car sales price and trade-in allowance).
• Separate the logic for processing sales from the form code by using methods in the Sale class. The Sale class must have a method (function) for each of the following:
1. to compute the cost of the accessories & finish,
2. to compute the sales tax,
3. to compute the subtotal, and
4. to compute the amount due.
• Accessories and Car Exterior Finish options are priced as shown in this table. These values should be given appropriate names and stored as module-level constant values in the Sale class or program (your option on how you set this up).
Accessory Price Finish Price
Stereo System $425.76 Standard No additional charge
Leather Interior $987.41 Pearlized $345.72
Computer Navigation $1,741.23 Customized Detailing $599.99
• At Design Mode:
o Disable the Clear button.
o Set the TabStop property for the buttons to False.
o Set the TabOrder to tab from the Car Sales Price to the Trade-In Allowance to the Accessories group box control (each check box will tab in turn in this control and are selected by pressing the space bar), to the Finish group box control (the up and down arrow keys move the selection).
• On Startup:
o Focus is set on the Car Sales Price textbox.
o The checkboxes are all unchecked.
o The Standard finish should be selected by default.
o All labels and text boxes are cleared (empty).
• Controlling Correct Data Entry. Enforce the following business rules:
o If the Car Sales Price is blank, display the message "Enter a Car Sales Price", then set the focus to the textbox.
o If the Car Sales Price is non-numeric, display the message "Car Sales Price Must Be a Number", then set the focus to the textbox and use the SelectAll() method to highlight the invalid data.
o If the Car Sales Price is a negative value, display the message "Car Sales Price Cannot Be Less Than Zero", then the focus to the textbox and use the SelectAll() method to highlight the invalid data.
o If the Trade-In Allowance is non-numeric, display the message "Car Sales Price Must Be a Number", then set the focus to the textbox and use the SelectAll() method to highlight the invalid data.
o If the Trade-In Allowance is a negative value, display the message "Car Sales Price Cannot Be Less Than Zero", then the focus to the textbox and use the SelectAll() method to highlight the invalid data.
o If the Trade-In Allowance is blank, do not display an error message. Instead, store the value 0.00 to the textbox.
o Do not allow the program to display more than one error message at a time, even if there is more than one business rule violated. This will give the system user an opportunity to correct each error one at a time.
• Calculate button:
o Compute all values and display them in the appropriate labels as shown on the form above.
o Format ALL output labels and text boxes as right-justified and currency-formatted ($)
o Disable the Calculate button; enable the Clear button.
• Clear button:
o The check boxes should be unchecked.
o The Exterior Finish radio buttons should be reset such that the Standard option button is selected.
o The text boxes and labels that display currency values should be cleared.
o Set the focus to the Car Sales Price text box.
o Enable the Calculate button; disable the Clear button
• Exit button: Close the form.
Computing the Label Values:
• System users can select any combination of accessories (none, one, two, or all three). System users can only select one finish. Compute the combined cost of all accessories and finish and display the value to the appropriate label.
• The Sales Tax is computed on both the Car Sales Price and the cost of Accessories and Finish. Store the Sales Tax Rate as a constant (0.08D)
• The Subtotal is computed by adding the Car's Sales Price, cost of Accessories and Finish, and Sales Tax amount. Display the Subtotal value formatted as currency to the label as shown in the form.
• The Amount Due is computed by subtracting the Trade-in Allowance from the Subtotal. Display the Amount Due value formatted as currency to the label as shown in the form.
More:
Add a second form that will display summary totals for the number of sales made, the total amount due for all sales, and the total, and the total trade-in value for all sales. Maintain the totals as shared read-only properties of the Sale class. Create property procedures for the Sale class that can be called to display the data to the Sales Summary form. The summary form should be similar to the one shown here:
• Add a Summary button on the Main form that, when clicked, will display the Sales Summary Form.
• The Close button on the Sales Summary form will close the Sales Summary form returning control to the Main form.
DUE November 4th
