Как удалить выбранный столбец в DataGrid? (С#/ВПФ)

Вы можете установить видимость в свернутом виде:

CsvGrid.Columns[i].Visibility = Visibility.Collapsed;

Изменение источника привязки:

ВПФ:

<Grid>
    <DataGrid x:Name = "TheGrid" ItemsSource = "{Binding dataTable}">
        <DataGrid.Columns>
            <DataGridTemplateColumn Header = "Delete">
                <DataGridTemplateColumn.CellTemplate>
                    <DataTemplate>
                        <CheckBox Tag = "2" Checked = "Remove_me"></CheckBox>
                    </DataTemplate>
                </DataGridTemplateColumn.CellTemplate>
            </DataGridTemplateColumn>
        </DataGrid.Columns>
    </DataGrid>
</Grid>

Код позади:

   DataTable dt1 = new DataTable();

   public MainWindow()
    {
        InitializeComponent();
        dt1 = new DataTable();

        dt1.Columns.Add("1");

        dt1.Columns.Add("2");

        dt1.Columns.Add("3");

        DataRow dr = dt1.NewRow();

        TheGrid.ItemsSource = dt1.DefaultView;
    }
    private void Remove_me(object sender, RoutedEventArgs e)
    {

        CheckBox checkbox = (CheckBox)sender;
        dt1.Columns.Remove(checkbox.Tag.ToString())

        TheGrid.ItemsSource = null;
        TheGrid.ItemsSource = dt1.DefaultView;

    }

CsvGrid.Items.Refresh();
CsvGrid.UpdateLayout();

for (int i = 0; i < CsvGrid.Columns.Count; i++)
{
    foreach (var checkBox in CheckBoxes.Children.OfType<CheckBox>().Where(x => x.IsChecked == true))
    {
        if (CsvGrid.Columns[i].Header.ToString() == checkBox.Tag.ToString()) CsvGrid.Columns.RemoveAt(i);
     }
}

CsvGrid.SelectAllCells();
CsvGrid.ClipboardCopyMode = DataGridClipboardCopyMode.IncludeHeader;
ApplicationCommands.Copy.Execute(null, CsvGrid);
String result = (string) Clipboard.GetData(DataFormats.Text);
CsvGrid.UnselectAllCells();

SaveFileDialog saveFileDialog = new SaveFileDialog();
saveFileDialog.FileName = "Document";
saveFileDialog.DefaultExt = ".xls";
saveFileDialog.Filter = "Excel|*.xls|Excel 2010|*.xlsx|CSV files (*.csv)|*.CSV";
saveFileDialog.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
if (saveFileDialog.ShowDialog() == true)
{
    File.WriteAllText(saveFileDialog.FileName, result.Replace(',', ' '));
    MessageBox.Show("File created!");
}