private void textbox_TextChanged_1(object sender, TextChangedEventArgs e) { CustomFilter updatedFilter = new CustomFilter(); updatedFilter.CurrentFilter = (sender as TextBox).Text; if (this.dataGrid.FilterDescriptors.Count > 0) { this.dataGrid.FilterDescriptors.RemoveAt(0); } this.dataGrid.FilterDescriptors.Add(new DelegateFilterDescriptor { Filter = updatedFilter }); }