Implement Search, Filter and Sort

This article will demonstrate how you can implement searching, filtering and sorting on RadTreeView data. The final result will look like this: radtreeview-search-filter-sort-overview

The purpose of this article is to demonstrate how you can implement additional logic to the RadTreeView control. This is why we will skip the definition of our models and view-model. For more detailed information you can scroll down to the end of the article and find a link to a downloadable, ready to run project.

The RadTreeView is a data-driven control, designed to display large amounts of hierarchical data and it does not provide searching, filtering and sorting functionality out of the box. Hence, such operations should be implemented on the data it represents. Below you can find sample implementation of:

Searching

The searching functionality is triggered when the Search button is pressed. Basically, we first get the entered text in the first TextBox and then we search if the Name of each Category contains it. If nothing is found - we search in that Category's Products. When an existing item is found it is selected and brought into the view port of the RadTreeView.

For more details examine the following code:

: Example 1: Implement Searching

        //the RadTreeView.ItemsSource collection is traversed to find an item by a provided name  
        string searchText = null; 
        private void Search(object sender, RoutedEventArgs e) 
        { 
            if (!string.IsNullOrEmpty(searchTextBox.Text)) 
            { 
                searchText = searchTextBox.Text.ToLower(); 
                foreach (Category category in radTreeView.ItemsSource) 
                { 
                    if (category.Name.ToLower().Contains(searchText)) 
                    { 
                        RadTreeViewItem item = radTreeView.GetItemByPath(category.Path); 
                        item.BringIntoView(); 
                        item.IsSelected = true; 
                        return; 
                    } 
                    foreach (Product product in category.Products) 
                    { 
                        if (product.Name.ToLower().Contains(searchText)) 
                        { 
                            RadTreeViewItem item = radTreeView.GetItemByPath(category.Path + "\" + product.Path); 
                            item.BringIntoView(); 
                            item.IsSelected = true; 
                            return; 
                        } 
                    } 
                } 
            } 
            isFiltered = false; 
        }   
    'the RadTreeView.ItemsSource collection is traversed to find an item by a provided name' 
    Dim searchText As String = Nothing 
    Private Sub Search(sender As Object, e As RoutedEventArgs) 
        If Not String.IsNullOrEmpty(searchTextBox.Text) Then 
            searchText = searchTextBox.Text.ToLower() 
            For Each category As Category In radTreeView.ItemsSource 
                If category.Name.ToLower().Contains(searchText) Then 
                    Dim item As RadTreeViewItem = radTreeView.GetItemByPath(category.Path) 
                    item.BringIntoView() 
                    item.IsSelected = True 
                    Return 
                End If 
                For Each product As Product In category.Products 
                    If product.Name.ToLower().Contains(searchText) Then 
                        Dim item As RadTreeViewItem = radTreeView.GetItemByPath(category.Path + "\" + product.Path) 
                        item.BringIntoView() 
                        item.IsSelected = True 
                        Return 
                    End If 
                Next 
            Next 
        End If 
        isFiltered = False 
    End Sub 

Filtering

The filtering functionality is triggered immediately when the text of the second TextBox is changed. The first step, again, is to get the text that is entered into the filterTextBox. After that, we call a helper method (which will also be used in the sorting functionality) that accepts as arguments a collection to sort and a filter string and returns a new filtered collection. With the help of that method we change the ItemsSource of the RadTreeView control so that it visualizes only the items that contain the filtering criteria.

Below you can examine the implementation of these two methods:

Example 2: Implement Filtering

        //the SampleDataSource collection is dynamically filtered to display only those items matching the filter criteria    
        string filterText = null; 
        private void filterTextBox_TextChanged(object sender, TextChangedEventArgs e) 
        { 
            if (!String.IsNullOrEmpty(filterTextBox.Text)) 
            { 
                filterText = filterTextBox.Text == " Enter product name" ? "" : filterTextBox.Text; 
                radTreeView.ItemsSource = FilterCollection(new SampleDataSource(), filterText); 
            } 
            else 
            { 
                radTreeView.ItemsSource = new SampleDataSource(); 
                filterText = null; 
            } 
            isFiltered = true; 
        } 
 
        //this method filters a business collection    
        private ObservableCollection<Category> FilterCollection(ObservableCollection<Category> collection, string filterText) 
        { 
            foreach (Category category in collection) 
            { 
                category.Products = new ObservableCollection<Product>(category.Products.Where(p => p.Name.ToLower().Contains(filterText))); 
            } 
            return new ObservableCollection<Category>(collection.Where(cat => (cat.Name.ToLower().Contains(filterText) && cat.Products.Count == 0) || cat.Products.Count > 0)); 
        } 
    'the SampleDataSource collection is dynamically filtered to display only those items matching the filter criteria' 
    Dim filterText As String = Nothing 
    Private Sub filterTextBox_TextChanged(sender As Object, e As TextChangedEventArgs) 
        If Not [String].IsNullOrEmpty(filterTextBox.Text) Then 
            filterText = If(filterTextBox.Text = " Enter product name", "", filterTextBox.Text) 
            radTreeView.ItemsSource = FilterCollection(New SampleDataSource(), filterText) 
        Else 
            radTreeView.ItemsSource = New SampleDataSource() 
            filterText = Nothing 
        End If 
        isFiltered = True 
    End Sub 
 
    'this method filters a business collection' 
    Private Function FilterCollection(collection As ObservableCollection(Of Category), filterText As String) As ObservableCollection(Of Category) 
        For Each category As Category In collection 
            category.Products = New ObservableCollection(Of Product)(category.Products.Where(Function(p) p.Name.ToLower().Contains(filterText))) 
        Next 
        Return New ObservableCollection(Of Category)(collection.Where(Function(cat) (cat.Name.ToLower().Contains(filterText) AndAlso cat.Products.Count = 0) OrElse cat.Products.Count > 0)) 
    End Function 

Sorting

The sort functionality is triggered when the selection of the ComboBox is changed. When the SelectionChanged event occurs we check the SelectedItem. and based on its Value, we sort the RadTreeView. collection.

Example 3: Implement Sorting

        //When the Sorting ComboBox selection is changed, the SampleDataSource collection is sorted accordingly         
        private void sortingComboBox_SelectionChanged(object sender, SelectionChangedEventArgs e) 
        { 
            if ((sortingComboBox.SelectedItem as RadComboBoxItem).Content.Equals("Category name")) 
            { 
                if (filterText != null) 
                { 
                    radTreeView.ItemsSource = FilterCollection(new SampleDataSource(), filterText).OrderBy(c => c.Name); 
                } 
                else 
                { 
                    radTreeView.ItemsSource = new SampleDataSource().OrderBy(c => c.Name); 
                } 
            } 
            else 
            { 
                if (filterText != null) 
                { 
                    radTreeView.ItemsSource = FilterCollection(new SampleDataSource(), filterText).OrderBy(c => c.Products.Count); 
                } 
                else 
                { 
                    radTreeView.ItemsSource = new SampleDataSource().OrderBy(c => c.Products.Count); 
                } 
            } 
            isFiltered = false; 
        }      
    'When the Sorting ComboBox selection is changed, the SampleDataSource collection is sorted accordingly'      
    Private Sub sortingComboBox_SelectionChanged(sender As Object, e As SelectionChangedEventArgs) 
        If TryCast(sortingComboBox.SelectedItem, RadComboBoxItem).Content.Equals("Category name") Then 
            If filterText IsNot Nothing Then 
                radTreeView.ItemsSource = FilterCollection(New SampleDataSource(), filterText).OrderBy(Function(c) c.Name) 
            Else 
                radTreeView.ItemsSource = New SampleDataSource().OrderBy(Function(c) c.Name) 
            End If 
        Else 
            If filterText IsNot Nothing Then 
                radTreeView.ItemsSource = FilterCollection(New SampleDataSource(), filterText).OrderBy(Function(c) c.Products.Count) 
            Else 
                radTreeView.ItemsSource = New SampleDataSource().OrderBy(Function(c) c.Products.Count) 
            End If 
        End If 
        isFiltered = False 
    End Sub  

You can download a runnable project demonstrating this approach from our online SDK repository. Please open this link and navigate to TreeView / FilterSearchSort.

See Also

In this article
Not finding the help you need? Improve this article