WISE OWL EXERCISES
VISUAL C# EXERCISES
- Creating forms (4)
- Coding form events (1)
- Laying out your code (2)
- C# variables (4)
- Enumerations and constants (2)
- Conditions (2)
- Modular code (3)
- Arrays (2)
- Looping (2)
- Files and folders (3)
- Properties in C# (3)
- Using lists (3)
- Validating forms (6)
- Toolbars, menus and status bars (1)
- FileDialogs and StreamReaders (1)
- Debugging and trapping errors (1)
- Introduction to DataGridViews (1)
- DataGridView events (3)
- Complex DataGridViews (2)
- Creating classes (2)
- The form as a class (1)
- Data structures (4)
- Inheritance (4)
- Interfaces (2)
- Delegates and events (2)
- Writing LINQ (1)
- Advanced LINQ (3)
- LINQ to SQL models (1)
- Writing LINQ to SQL (2)
- Grouping using LINQ (2)
Visual C# | Creating classes exercise | Use basic classes to create a shopping list app in C#
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In a new or existing project, create a new from called frmShoppingList to look like this:
Call the text boxes txtItem, txtUnit and txtAmount, and the listbox txtList.
First add code to the Cancel button (it should just close the form, which being the current object you can refer to as this).
Create a class called ShoppingList, and create 3 private fields to hold the 3 things being entered:
// private fields for each textbox
private string itemName;
private string unit;
private double amount;
Create one public property for each of these private fields, to expose the value of it to the world.
Attach code to the Add item button which will create a new instance of the ShoppingList class, and make it work (well, soon):
// can now create and add to list new item
ShoppingItem thing = new ShoppingItem();
// could use our amount property here
thing.Amount = Convert.ToDouble(txtAmount.Text);
thing.ItemName = txtItem.Text;
thing.Unit = txtUnit.Text;
thing = null;
You can assume that a user has typed in sensible things in each of the 3 text boxes, although the answer given does trap for this.
The only thing left now is to create the Add method for the ShoppingItem class. This should take a TextBox as an argument (hint: you may need to add an additional using statement at the top of your class).
Run your application and try adding a few items:
What the form might look like after adding 3 items.
Close down your application and all open files (don't worry about the fact that this loses your shopping list - you can always create another ...).