c# WPF: DataGrid Delete Selected Row

Hi everyone

I have a datagrid, which I linked to a list as a source, and in a column I put a button to delete the row until the user clicked on that row to delete it.

But I get the following error !!

Thanks for the guidance everyone

<pre>   <DataGrid VerticalAlignment="Center" VerticalContentAlignment="Center" HorizontalContentAlignment="Center" HorizontalAlignment="Center" IsEnabled="{Binding ElementName=chkitems, Path=IsChecked}"  Height="266" x:Name="dgvitems" AutoGenerateColumns="False" CanUserAddRows="True" CanUserDeleteRows="True" CanUserReorderColumns="False" CanUserResizeColumns="False" CanUserSortColumns="False" IsReadOnly="False" Width="451">
                        <DataGrid.Columns>
                            <DataGridTextColumn Header="نام کالا" Width="250" FontSize="14" Binding="{Binding name}"/>
                            <DataGridTextColumn Header="تعداد" Width="80" FontSize="14" Binding="{Binding number}"/>
                            <DataGridTemplateColumn Header=" ">
                                <DataGridTemplateColumn.CellTemplate >
                                    <DataTemplate>
                                        
                                        <Button x:Name="btndelete"  VerticalAlignment="Center" HorizontalAlignment="Center"  BorderBrush="{x:Null}" Click="Btndelete_Click" ToolTip="حذف رکورد" Background="{x:Null}">
                                            <materialDesign:PackIcon Kind="CloseCircle" Foreground="Red" Width="16" Height="16" HorizontalAlignment="Center" VerticalAlignment="Center" HorizontalContentAlignment="Center" VerticalContentAlignment="Center"/>
                                        </Button>
                                    </DataTemplate>
                                </DataGridTemplateColumn.CellTemplate>
                            </DataGridTemplateColumn>
                        </DataGrid.Columns>
                        
                    </DataGrid>

<pre lang="c#">

 public class datagridset
            {
            
            public string name { get; set; }
            public int number { get; set; }
        };


          -----

             <pre> private void Window_Loaded(object sender, RoutedEventArgs e)
        {
            List<datagridset> datagridsets = new List<datagridset>();
            dgvitems.ItemsSource = datagridsets.ToList();
        }

        ------
                 private void Btndelete_Click(object sender, RoutedEventArgs e)
        {
           if(dgvitems.SelectedItem!=null)
            {
                dgvitems.Items.Remove(dgvitems.SelectedItem);
            }
        }