DataSourceSorting.cs

#region Copyright Syncfusion Inc. 2001-2019.
// Copyright Syncfusion Inc. 2001-2019. All rights reserved.
// Use of this code is subject to the terms of our license.
// A copy of the current license can be obtained at any time by e-mailing
// licensing@syncfusion.com. Any infringement will be prosecuted under
// applicable laws. 
#endregion
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

using Android.App;
using Android.Content;
using Android.OS;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Syncfusion.DataSource;
using Android.Graphics;

namespace SampleBrowser
{
    public class DataSourceSorting : SamplePage, IDisposable
    {
        #region Fields

        private DataSource dataSource;
        private ContatsViewModel viewModel;
        private ListView listView;
        private Spinner groupDropdown;
        private GridLayout gridlayout;
        private TextView groupTextView;
        private SearchView filterText;

        #endregion

        #region Override

        public override Android.Views.View GetSampleContent(Android.Content.Context context)
        {
            LinearLayout linear = new LinearLayout(context) { Orientation = Orientation.Vertical };
            listView = new ListView(context);
            listView.FastScrollEnabled = true;
            viewModel = new ContatsViewModel();
            dataSource = new DataSource();
            dataSource.Source = viewModel.ContactsList;
            dataSource.LiveDataUpdateMode = LiveDataUpdateMode.AllowDataShaping;
            dataSource.SortDescriptors.Add(new SortDescriptor("ContactName", Syncfusion.DataSource.ListSortDirection.Ascending));
            listView.Adapter = new ContactsAdapter(dataSource, context);
            filterText = new SearchView(context);
            filterText.SetIconifiedByDefault(false);
            filterText.SetPadding(0, 0, 0, (int)(10 * context.Resources.DisplayMetrics.Density));
            filterText.SetQueryHint("Search contact");
            filterText.QueryTextChange += OnFilterTextChanged;
            linear.AddView(new LinearLayout(context) { Focusable = true, FocusableInTouchMode = true }, 0, 0);
            linear.AddView(filterText);
            linear.AddView(listView);
            return linear;
        }

        public override View GetPropertyWindowLayout(Context context)
        {
            gridlayout = new GridLayout(context);
            gridlayout.SetPadding(20, 20, 20, 20);
            gridlayout.RowCount = 2;
            gridlayout.ColumnCount = 2;
            groupTextView = new TextView(context);
            groupTextView.Text = "Sort by";
            groupDropdown = new Spinner(context, SpinnerMode.Dialog);
            var groupAdapter = new ArrayAdapter(context, Android.Resource.Layout.SimpleSpinnerItem);
            groupAdapter.SetDropDownViewResource(Android.Resource.Layout.SimpleSpinnerDropDownItem);
            groupAdapter.Add("Ascending");
            groupAdapter.Add("Descending");

            groupDropdown.Adapter = groupAdapter;
            groupDropdown.ItemSelected += GroupDropdown_ItemSelected;

            gridlayout.AddView(groupTextView, LinearLayout.LayoutParams.WrapContent, (int)(30 * context.Resources.DisplayMetrics.Density));
            gridlayout.AddView(groupDropdown);
            return gridlayout;
        }

        private void GroupDropdown_ItemSelected(object sender, AdapterView.ItemSelectedEventArgs e)
        {
            var spinner = sender as Spinner;
            var direction = spinner.GetItemAtPosition(e.Position).ToString();
            dataSource.BeginInit();

            dataSource.SortDescriptors.Clear();
            dataSource.SortDescriptors.Add(new SortDescriptor()
            {
                PropertyName = "ContactName",
                Direction = direction == "Ascending" ? Syncfusion.DataSource.ListSortDirection.Ascending : Syncfusion.DataSource.ListSortDirection.Descending
            });
            dataSource.EndInit();
            (this.listView.Adapter as ContactsAdapter).NotifyDataSetChanged();
        }

        private void OnFilterTextChanged(object sender, SearchView.QueryTextChangeEventArgs e)
        {
            if (dataSource != null)
            {
                this.dataSource.Filter = FilterContacts;
                this.dataSource.RefreshFilter();
            }
        }

        private bool FilterContacts(object obj)
        {
            var contacts = obj as Contacts;
            if (contacts.ContactName.ToLower().Contains(filterText.Query.ToLower())
                || contacts.ContactNumber.ToLower().Contains(filterText.Query.ToLower()))
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        public void Dispose()
        {
            if (dataSource != null)
            {
                dataSource.Dispose();
                dataSource = null;
            }

            if (gridlayout != null)
            {
                gridlayout.Dispose();
                gridlayout = null;
            }

            if (groupDropdown != null)
            {
                groupDropdown.Dispose();
                groupDropdown = null;
            }

            if (groupTextView != null)
            {
                groupTextView.Dispose();
                groupTextView = null;
            }

            if (listView != null)
            {
                listView.Dispose();
                listView = null;
            }

            if (filterText != null)
            {
                filterText.Dispose();
                filterText = null;
            }
        }

        #endregion
    }
}