CD Publisher

In this exercise, we will develop an application for a small CD publishing company. The owner wants the prices to be calculated so a customer would get a discount if he orders more. To attract customers and encourage them to order more, she has decided to fix the prices so that the customer would pay:

• $20/CD if he orders less than 20 units
• $15/CD if he orders less than 50 units
• $12/CD if he orders less than 100 units
• $8/CD if he orders less than 500 units
• $5/CD if he orders more than 500 units

1. Start Visual Studio
2. Create a new Visual Basic Windows Application and name it CDPublisher
3. Design the form as follows:
    

   Control Name Text Other Properties Label   Number of CDs:   NumericUpDown updQuantity   Maximum: 10000 TextAlign: Center Label   Unit Price:   TextBox txtUnitPrice 0 TextAlign: Right Label   Total Price:   TextBox txtTotalPrice 0 TextAlign: Right Button btnClose Close

4. Double-click the Close button and implement it as follows:
    

   Private Sub btnClose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClose.Click Close() End Sub

5. Double-click the up down button to access its OnChange() event and implement it as follows:
    

   Private Sub updQuantity_ValueChanged(ByVal sender As System.Object, _ ByVal e As System.EventArgs) Handles updQuantity.ValueChanged Dim Quantity As Integer Dim UnitPrice, TotalPrice As Double Quantity = updQuantity.Value If Quantity < 20 Then UnitPrice = 20 ElseIf Quantity < 50 Then UnitPrice = 15 ElseIf Quantity < 100 Then UnitPrice = 12 ElseIf Quantity < 500 Then UnitPrice = 8 Else UnitPrice = 5 End If TotalPrice = Quantity * UnitPrice txtUnitPrice.Text = UnitPrice.ToString("C") txtTotalPrice.Text = TotalPrice.ToString("C") End Sub

6. Test the application
7. Close it