WISE OWL EXERCISES
VISUAL BASIC EXERCISES
VISUAL BASIC EXERCISES
- Drawing forms (2)
- Form events (1)
- Variables and data types (2)
- Enumerations and constants (2)
- Form validation (3)
- Menus and toolbars (2)
- Files and folders (1)
- Basic DataGridViews (1)
- Reacting to DataGridView events (3)
- Advanced DataGridViews (2)
- Creating classes (4)
- Coding in VB.NET (2)
- Variables and constants (3)
- Testing conditions (2)
- Passing arguments (3)
- Using arrays (2)
- Loops (2)
- Working with files (3)
- Lists (3)
- Creating properties (3)
Visual Basic | Creating classes exercise | Create classes to facilitate writing your shopping list
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You can learn how to do this exercise on the relevant Wise Owl classroom training course (sadly for the moment only in the UK).
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Right-click on your project in Solution Explorer and choose to add the form from the above folder (you can alternatively press SHIFT + ALT + A ).
The initial form. The idea is that when you type in an item and click on the Add Item button, it will be added to the list on the right.
First add code to the Cancel button so that clicking on it closes the form.
Remember that you can use me to refer to the current form.
Create a class called ShoppingList. Within this, create 3 simple properties, to hold the item name, unit and amount. Here's an example for the item name:
'item name property
Private _ItemName As String = ""
Public Property ItemName As String
Set(value As String)
_ItemName = value
You should now be able to attach code to the Add Item button which:
- Creates a new instance of your ShoppingList class;
- Sets the item name, unit and amount properties.
The only thing you need to add now is the code to add the item to the textbox on the right of the form. To do this you could add a public method to your class, which passes in the textbox to which you want to add text:
Public Sub Add(ListTextBox As TextBox)
'add a blank line if appropriate
If ListTextBox.Text.Length > 0 Then _
ListTextBox.Text &= vbCrLf
'add item to the list of items
ListTextBox.Text &= Amount.ToString("0.00") & _
" " & Unit & " of " & ItemName
Make sure that you call this method at the end of your Add Item button code, and test your system to check that it accumulates items to buy:
You'll gradually accumulate items in your list.
Test that your system works, then close the form down (don't worry for now that this will then lose your shopping list!).