Question

I am developing a WPF application.There is a datagrid in my Application i have created a context menu to hide and unhide column header of the datagrid while assigning the itemsource of datagrid to an IEnumerable collection.

 this.dataGrid1.ItemsSource = objref.Result;


                grid_data = objref.Result;
                cxMenu = new ContextMenu();

                foreach (Microsoft.Windows.Controls.DataGridColumn item in dataGrid1.Columns)
                {
                    menuItem = new MenuItem();
                    menuItem.Header = item.Header;
                    menuItem.IsChecked = true;
                    cxMenu.Items.Add(menuItem);
                    menuItem.Click += new RoutedEventHandler(menuItem_Click);
                    menuItem.Checked += new RoutedEventHandler(menuItem_Checked);
                    menuItem.Unchecked += new RoutedEventHandler(menuItem_Unchecked);
                }

Everythjing working fine. when i uncheck the columns are successfully remobved but when i again check the MenuItem of my ContextMenu it is not added.

Handler of my check event is as follows.

 void menuItem_Checked(object sender, RoutedEventArgs e)
    {
        MenuItem item = sender as MenuItem;
        dataGrid1.ItemsSource = null;
        dataGrid1.ItemsSource = objref.Result;// Again assgining the whole set to itemssource
        List<string> menuList = new List<string>();
        menuList.Clear();



    foreach (MenuItem menuItem in cxMenu.Items)
    {
        if (menuItem.IsChecked == false)
        {
            menuList.Add(menuItem.Header.ToString());
        }
    }

        Functionsclass objref = new Functionsclass();


        foreach (string menuItem in menuList)
        {
            foreach (Microsoft.Windows.Controls.DataGridColumn column in dataGrid1.Columns)
            {
                if (column.Header.ToString() == menuItem)
                {
                    dataGrid1.Columns.Remove(column);
                    break;
                }
            }
        }
    }

But my column is not added when i check again. Please help me on this.

Update 2:

 void menuItem_Click(object sender, RoutedEventArgs e)
    {
        MenuItem item = sender as MenuItem;
        if (item.IsChecked)
        {
            item.IsChecked = false;
        }
        else
        {
            item.IsChecked = true;
        }
    }

    void menuItem_Unchecked(object sender, RoutedEventArgs e)
    {
        MenuItem item = sender as MenuItem;
        foreach (Microsoft.Windows.Controls.DataGridColumn column in dataGrid1.Columns)
        {
            if (column.Header.ToString().Contains(item.Header.ToString()))
            {
                dataGrid1.Columns.Remove(column);
                break;
            }
        }
    }

Uncheck handler.

Answer 1

If you just want to hide/show columns, I don’t think Removing/Adding columns is the right approach. I suggest you make use of the Visibility property of the column. set it to Visibility.Collapsed to hide it, then Visibility.Visible to make it visible again.

column.Visibility = Visibility.Collapsed; // Column is hidden

column.Visibility = Visibility.Visible; //Column is Visible