Question

I have a listview and a search textbox. When I type any character or symbol into the textbox, then it matches the typed text with the listbox items. If there is any match then it highlights the matched item. In that point, I want to remove the not matched items from the listview. Only the matched items will remain in the listview. What do you recommend me to solve that ? My other code is below.

 private void TxtSearch_PreviewKeyUp(object sender, System.Windows.Input.KeyEventArgs e)
 {
        ListControl lc = getactivListview();
        FindListViewItem(lc);
 }


 private void FindListViewItem(DependencyObject obj)
    {
        for (int i = 0; i < VisualTreeHelper.GetChildrenCount(obj); i++)
        {
            ListViewItem lv = obj as ListViewItem;
            if (lv != null)
            {
                HighlightText(lv);
            }
            FindListViewItem(VisualTreeHelper.GetChild(obj as DependencyObject, i));
        }
    }

    private void HighlightText(Object itx)
    {
        if (itx != null)
        {
            if (itx is TextBlock)
            {
                Regex regex = new Regex("(" +TxtSearch.Text + ")", RegexOptions.IgnoreCase);
                TextBlock tb = itx as TextBlock;
                if (TxtSearch.Text.Length == 0)
                {
                    string str = tb.Text;
                    tb.Inlines.Clear();
                    tb.Inlines.Add(str);
                    return;
                }
                string[] substrings = regex.Split(tb.Text);
                tb.Inlines.Clear();
                foreach (var item in substrings)
                {
                    if (regex.Match(item).Success)
                    {
                        Run runx = new Run(item);
                        runx.Background = Brushes.Lime;
                        tb.Inlines.Add(runx);

                        if (tb.IsMouseOver)
                        {
                            tb.IsEnabled = false;
                        }
                    }
                    else
                    {
                        tb.Inlines.Add(item);
                        tb.IsEnabled = false;
                    }
                }

                return;
            }
            else
            {
                for (int i = 0; i < VisualTreeHelper.GetChildrenCount(itx as DependencyObject); i++)
                {
                    HighlightText(VisualTreeHelper.GetChild(itx as DependencyObject, i));
                }
            }
        }
    }

Answer 1

Well, the easiest and most natural way in WPF is use of databinding and filter ModelView collection on it.

for example:

public class ModelView 
{
    private IEnumerable<Data> _data = ....
    public string Filtrer {get;set;}

    public IEnumerable<Data> GetData() {

          return FilteredData();
    }

    private IEnumerable<Data> FilteredData()
   {
      if(string.IsNullOrEmpty(Filter))
         return _data;

      return   _data.Where(x=>x...Filter); //SOME CONDITON EXECUTION
   }
}

You bind to view GetData() which return either full or filtered collection, based on the absence or presence of the filter string.

Like an example how can be databinding implemented on ListView (it’s not a shot topic and hardly can be explained in this simple answer), can have a look on: Data Binding in WPF ListView