how can I take one class properties to another class in C# WPF?

Question

I am new to C# WPF and I am creating an application to add Item details to a form. My problem is I want to add item details from a wpf window to a datagrid which is in the main window. I created a class and add properties to set and get values. but I cannot get returns to main window from class. And I want to add those items to the datagrid too. [

Class Code:

public class AddItemToPRGrid
{
    public string ItemNo { get; set; }
    public string ItemName { get; set; }
    public int Qty { get; set; }
    public DateTime expDate { get; set; }
}

Add Items Window Code:

public partial class PnlAddItem : Window
{
    public PnlAddItem()
    {
        InitializeComponent();
    }
    public static string no;
    private void btnAddItem_Click(object sender, RoutedEventArgs e)
    {
        AddItemToPRGrid addItemToPRGrid = new AddItemToPRGrid();
        addItemToPRGrid.ItemNo = txtItemNo.Text;
        addItemToPRGrid.ItemName = txtItemName.Text;
        addItemToPRGrid.Qty = Convert.ToInt32(txtItemQty.Text);
        addItemToPRGrid.expDate = (DateTime)dpItemExpDate.SelectedDate;
        this.Visibility = Visibility.Hidden;
        
    }
}

Main Window Code:

public partial class MainWindow : Window
{
    public MainWindow()
    {
        InitializeComponent();
    }

    private void btnCreatePR_Click(object sender, RoutedEventArgs e)
    {
        AddItemToPRGrid addItemToPRGrid = new AddItemToPRGrid();

        //This MessageBox is used to identify whether the value is return from class
        MessageBox.Show(addItemToPRGrid.ItemNo);
    }
    private void btnAddItem_Click(object sender, RoutedEventArgs e)
    {
        
        PnlAddItem AddItemWindow = new PnlAddItem();
        AddItemWindow.ShowDialog();
    }
}

XAML Code:

<Grid Height="250">
    <DataGrid x:Name="dataGridAddItem" 
              CanUserAddRows="True"
              ColumnWidth="*">
        <DataGrid.Columns>
            <DataGridTextColumn Header="Item No" Binding="{Binding ino}"/>
            <DataGridTextColumn Header="Item Name" Binding="{Binding iname}"/>
            <DataGridTextColumn Header="Quantity" Binding="{Binding qty}"/>
            <DataGridTextColumn Header="Expiry Date" Binding="{Binding expirydate}"/>
        </DataGrid.Columns>
    </DataGrid>
</Grid>

Answer 1

you can return result via property:

public partial class PnlAddItem : Window
{
    public PnlAddItem()
    {
        InitializeComponent();
    }

    public AddItemToPRGrid Item { get; private set; }

    private void btnAddItem_Click(object sender, RoutedEventArgs e)
    {
        Item = new AddItemToPRGrid 
        {
            ItemNo = txtItemNo.Text,
            ItemName = txtItemName.Text,
            Qty = Convert.ToInt32(txtItemQty.Text),
            expDate = (DateTime)dpItemExpDate.SelectedDate
        };
        this.Close();            
    }
}

then add it to DataGrid:

private void btnAddItem_Click(object sender, RoutedEventArgs e)
{
    var AddItemWindow = new PnlAddItem();
    AddItemWindow.ShowDialog();
    if (AddItemWindow.Item != null)
    {
        // add to datagrid, e.g. MainDataGrid.Items.Add(AddItemWindow.Item);
    }
}