Please complete in C#

In this exercise, you'll add two classes to the Inventory Maintenance app that inherit

the InventoryItem class. Then, you'll add code to the forms to provide for these new

classes.

$1.$Open the InventoryMaintenance project in the ExtraStarts $\frac{\frac{?}{?}}{?}$ Ch $14$ directory. Then,

review the code for the New Item form to see that the items in the combo box

and the label for the combo box depend on which radio button is selected.

$2.$Display the InventoryItem class and modify the GetDisplayText $()$ method so it's

overridable.

$3.$Add a class named Plant that inherits the InventoryItem class. This new class

should add a string property named Size. It should also provide a default

constructor and a constructor that accepts four parameters $($item number,

description, price, and size$)$ to initialize the class properties. This constructor

should call the base class constructor to initialize the properties defined by that

class. Finally, this class should override the GetDisplayText$()$ method to add the

size in front of the description, as in this example:

$32456491$ gallon Agapanthus $($$$7\mathrm{.}95)$

$4.$Add another class named Supply that inherits the InventoryItem class and adds a

string property named Manufacturer. Like the Plant class, the Supply class

should provide a default constructor and a constructor that accepts four

parameters, and it should override the GetDisplayText method so the

manufacturer is added in front of the description like this:

$9210584$ Ortho Snail pellets $($$$12\mathrm{.}95)$

$5.$Modify the event handler for the Click event of the Save button on the New Item

form so it creates a new item of the appropriate type using the data entered by the

user.

$6.$Modify the event handler for the Click event of the Add button on the Inventory

Maintenance form so it displays a dialog indicating that the item has been added

successfully, as shown above. The message should use the Size and Description

properties for a Plant object, and the Manufacturer and Description properties for

a Supply object.

$7.$Test the app by adding at least one of each type of inventory item.

This is the code I have so far:

using System.Xml$.$Linq;

namespace InventoryMaintenance

$\{$

public partial class frmNewItem : Form

$\{$

public frmNewItem$()$

$\{$

InitializeComponent$()$;

$\}$

private InventoryItem item $=$ null!;

public InventoryItem GetNewItem$()$

$\{$

rdoPlant.Checked $=$ true;

this.ShowDialog$()$;

return item;

$\}$

private void rdoPlant$\_$CheckedChanged$($object sender$,$ EventArgs e$)$

$\{$

if $($rdoPlant$.$Checked$)$

lblSizeOrManufacturer.Text $=$ "Size:";

else

lblSizeOrManufacturer.Text $=$ "Manufacturer:";

LoadComboBox$()$;

$\}$

private void LoadComboBox$()$

$\{$

cboSizeOrManufacturer.Items.Clear$()$;

if $($rdoPlant$.$Checked$)$

$\{$

cboSizeOrManufacturer.Items.Add$("1$ gallon"$)$;

cboSizeOrManufacturer.Items.Add$("5$ gallon"$)$;

cboSizeOrManufacturer.Items.Add$("15$ gallon"$)$;

cboSizeOrManufacturer.Items.Add$("24-$inch box"$)$;

cboSizeOrManufacturer.Items.Add$("36-$inch box"$)$;

$\}$

else

$\{$

cboSizeOrManufacturer.Items.Add$("$Bayer$")$;

cboSizeOrManufacturer.Items.Add$("$Jobe$\text{'}$s$")$;

cboSizeOrManufacturer.Items.Add$("$Ortho$")$;

cboSizeOrManufacturer.Items.Add$("$Roundup$")$;

cboSizeOrManufacturer.Items.Add$("$Scotts$")$;

$\}$

$\}$

private void btnSave$\_$Click$($object sender$,$ EventArgs e$)$

$\{$

if $($IsValidData$())$

$\{$

item $=$ new$($

Convert.ToInt$32($txtItemNo$.$Text$),$

txtDescription.Text,

Convert.ToDecimal$($txtPrice$.$Text$)$

$)$;

this.Close$()$;

$\}$

$\}$

private bool IsValidData$()$

$\{$

bool success $=$ true;

string errorMessage $=""$;

errorMessage $+=$ Validator.IsPresent$($txtItemNo$.$Text, "Item no$")$;

errorMessage $+=$ Validator.IsInt$32($txtItemNo$.$Text, "Item no$")$;

errorMessage $+=$ Validator.IsPresent$($txtDescription$.$Text, "Description"$)$;

errorMessage $+=$ Validator.IsPresent$($txtPrice$.$Text, "Price"$)$;

errorMessage $+=$ Validator.IsDecimal$($txtPrice$.$Text, "Price"$)$;

$//$ Validate combo box $-$ use label text for name $-$ remove ending colon

string name $=$ lblSizeOrManufacturer.Text.Substring$(0,$ lblSizeOrManufacturer.Text.Length $-1)$;

errorMessage $+=$ Validator.IsSelected$($cboSizeOrManufacturer$.$SelectedIndex, name$)$;

if $($errorMessage $!="")$

$\{$

success $=$ false;

MessageBox.Show$($errorMessage$,$ "Entry Error"$)$;