/// <summary>
    /// The class extends the functionality of a DataGridView with filtering
    /// </summary>
    [Serializable()]
    [ToolboxBitmap(typeof(DataGridView))]
    public partial class FilterableDataGridView : DataGridView
    {
        /// <summary>
        /// A collection to store the filters
        /// </summary>
        /// <remarks>
        /// ObservableCollection&lt;T&gt; requires .NET 4.0
        /// </remarks>
        private ObservableCollection<FilterItem> _filters;

        /// <summary>
        /// Property to get or set the collection of the filters
        /// </summary>
        [DesignerSerializationVisibility(DesignerSerializationVisibility.Content)]
        public ObservableCollection<FilterItem> Filters
        {
            get
            {
                return _filters;
            }
            set
            {
                _filters = value;

                if (_filters != null)
                {
                    // Subscribe to the CollectionChanged event, so the filtering can be done automatically
                    _filters.CollectionChanged += new System.Collections.Specialized.NotifyCollectionChangedEventHandler(_filters_CollectionChanged);
                }
            }
        }

        /// <summary>
        /// The event handler of the filters CollectionChanged event,
        /// so the filtering can be automatic when the collection changes
        /// </summary>
        /// <param name="sender">sender</param>
        /// <param name="e">Event arguments</param>
        void _filters_CollectionChanged(object sender, System.Collections.Specialized.NotifyCollectionChangedEventArgs e)
        {
            //If a new element is added
            if (e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Add)
            {
                foreach (FilterItem fi in e.NewItems)
                {
                    //subscribe to its event, so filtering will be done automatically every time when the filter changes
                    fi.FilterChanged += Filter;
                }
            }
            //If the filter is removed
            else if (e.Action == System.Collections.Specialized.NotifyCollectionChangedAction.Remove)
            {
                foreach (FilterItem fi in e.OldItems)
                {
                    //unsubscribe from its event
                    fi.FilterChanged -= Filter;
                }
            }

            //Finally filter the list
            Filter();
        }

        /// <summary>
        /// Constructor
        /// </summary>
        public FilterableDataGridView()
        {
            InitializeComponent();

            Filters = new ObservableCollection<FilterItem>();
        }

        /// <summary>
        /// Constructor
        /// </summary>
        /// <param name="container"></param>
        public FilterableDataGridView(IContainer container)
        {
            container.Add(this);

            InitializeComponent();

            Filters = new ObservableCollection<FilterItem>();
        }

        /// <summary>
        /// Method to filter the DataGridView
        /// It gets called whenever the filters collection changes or a filter changes.
        /// Explicit call is possible, however not necessary.
        /// </summary>
        public void Filter()
        {
            //Set the selected cell to null, so every cell(/row) can be hidden
            this.CurrentCell = null;
            //Check every row in the DataGridView
            foreach (DataGridViewRow row in Rows)
            {

                bool visible = true;
                //Check every FilterItem
                foreach (FilterItem fi in _filters)
                {
                    //The char used to delimit the columns from each other
                    // it is also used to denote an OR relation ship between the filter texts
                    char c = '|';
                    //Split the string to column names
                    List<string> columns = new List<string>(fi.FilterColumn.Split(c));
                    List<string> filters = new List<string>(fi.Filter.Split(c));
                    bool atLeastOneContains = false;

                    //Check every columns
                    foreach (string column in columns)
                    {
                        foreach (string filter in filters)
                        {
                            if (row.Cells[column].Value != null && row.Cells[column].Value.ToString().ToUpper().Contains(filter.ToUpper()))
                            {
                                //If the column contains any of the filter texts, the filter is satisfied
                                atLeastOneContains = true;
                                break;
                            }
                        }
                        if (atLeastOneContains)
                        {
                            //If the column contains the filter text, the filter is satisfied
                            break;
                        }
                    }
                    //If none of the columns contain the text, the row can't be visible
                    if (!atLeastOneContains)
                    {
                        visible = false;
                        break;
                    }
                }
                //Set the Visible property the Row
                row.Visible = visible;
            }
        }
    }