Sorting in Xamarin ListView (SfListView)
17 Aug 202113 minutes to read
The SfListView
supports sorting the data either in ascending or descending order by using DataSource.SortDescriptors property and by using the custom logic.
NOTE
When
ItemsSource
changed for ListView,DataSource.SortDescriptors
will be cleared by default. You need to addDataSource.SortDescriptors
again after changingItemsSource
if you want to retain sorting in listview.
NOTE
To sort the newly added listview items at runtime, set the SfListView.DataSource.LiveDataUpdateMode to LiveDataUpdateMode.AllowDataShaping. To learn more details about the
LiveDataUpdateMode
, refer to here.
Programmatic sorting
Sorting the data by creating the SortDescriptor with required property name and direction and adding it into the DataSource.SortDescriptors property.
SortDescriptor
object holds the following three properties:
- PropertyName: Describes the name of the sorted property.
- Direction: Describes an object of type ListSortDirection that defines the sorting direction.
- Comparer: Describes the comparer to be applied when sorting take place.
<ContentPage xmlns:syncfusion="clr-namespace:Syncfusion.ListView.XForms;assembly=Syncfusion.SfListView.XForms"
xmlns:data="clr-namespace:Syncfusion.DataSource;assembly=Syncfusion.DataSource.Portable">
<sync:SfListView x:Name="listView">
<sync:SfListView.DataSource>
<data:DataSource>
<data:DataSource.SortDescriptors>
<data:SortDescriptor PropertyName="ContactName" Direction="Ascending"/>
</data:DataSource.SortDescriptors>
</data:DataSource>
</sync:SfListView.DataSource>
</syncfusion:SfListView>
</ContentPage>
listView.DataSource.SortDescriptors.Add(new SortDescriptor()
{
PropertyName = "ContactName",
Direction = ListSortDirection.Ascending,
});
listView.RefreshView();
NOTE
It is mandatory to specify the
PropertyName
ofSortDescriptor
.
Custom sorting
Sort the items based on the custom logic and it can be applied to either SfListView.DataSource.SortComparer property or SortDescriptor.Comparer which is added into theĀ DataSource.SortDescriptors collection.
You can download the entire sample code from the github.
NOTE
If the
PropertyName
in the SortDescriptor andGroupDescriptor
are same then, GroupResult will be passed as parameters for theSortDescriptor.Comparer
. Otherwise data objects are passed. To sort the data items alone, set the differentPropertyName
in bothSortDescriptor
andGroupDescriptor
properties.
<ContentPage xmlns:syncfusion="clr-namespace:Syncfusion.ListView.XForms;assembly=Syncfusion.SfListView.XForms"
xmlns:data="clr-namespace:Syncfusion.DataSource;assembly=Syncfusion.DataSource.Portable">
<ContentPage.Resources>
<ResourceDictionary>
<local:CustomSortComparer x:Key="CustomSortComparer" />
</ResourceDictionary>
</ContentPage.Resources>
<syncfusion:SfListView x:Name="listView"
<syncfusion:SfListView.DataSource>
<data:DataSource>
<data:DataSource.SortDescriptors>
<data:SortDescriptor Comparer="{StaticResource CustomSortComparer}"/>
</data:DataSource.SortDescriptors>
</data:DataSource>
</syncfusion:SfListView.DataSource>
</syncfusion:SfListView>
</ContentPage>
listView.DataSource.SortDescriptors.Add(new SortDescriptor()
{
Comparer = new CustomSortComparer()
});
public class CustomSortComparer : IComparer<object>
{
public int Compare(object x, object y)
{
if (x.GetType() == typeof(ListViewContactsInfo))
{
var xitem = (x as ListViewContactsInfo).ContactName;
var yitem = (y as ListViewContactsInfo).ContactName;
if (xitem.Length > yitem.Length)
{
return 1;
}
else if (xitem.Length < yitem.Length)
{
return -1;
}
else
{
if (string.Compare(xitem, yitem) == -1)
return -1;
else if (string.Compare(xitem, yitem) == 1)
return 1;
}
}
return 0;
}
}
For more information about custom sorting of groups, please refer the documentation here.
Sort the items on header tapped
To apply the sorting when tapping the header, handle the ItemTapped event of the SfListView
.
<ContentPage xmlns:syncfusion="clr-namespace:Syncfusion.ListView.XForms;assembly=Syncfusion.SfListView.XForms"
xmlns:data="clr-namespace:Syncfusion.DataSource;assembly=Syncfusion.DataSource.Portable">
<syncfusion:SfListView x:Name="listView" ItemSize="60"
ItemsSource="{Binding customerDetails}"
ItemTapped="ListView_ItemTapped"
IsStickyHeader="True">
<syncfusion:SfListView.HeaderTemplate>
<DataTemplate>
<ViewCell>
<ViewCell.View>
<StackLayout BackgroundColor="Teal">
<Label TextColor="White" FontSize="20" FontAttributes="Bold" Text="CustomerDetails" />
</StackLayout>
</ViewCell.View>
</ViewCell>
</DataTemplate>
</syncfusion:SfListView.HeaderTemplate>
</syncfusion:SfListView>
</ContentPage>
listView = new SfListView();
listView.ItemsSource = viewModel.customerDetails;
listView.ItemSize = 60;
listView.ItemTapped += ListView_ItemTapped;
listView.IsStickyHeader = true;
listView.HeaderTemplate = new DataTemplate(() =>
{
var stackLayout = new StackLayout { BackgroundColor = Color.Teal };
var label = new Label { Text = "CustomerDetails", TextColor = Color.White,
FontAttributes = FontAttributes.Bold, FontSize = 20 };
stackLayout.Children.Add(label);
return stackLayout;
});
When the ItemTapped
event is raised for the Header, add the SortDescriptor and refresh the view.
private void ListView_ItemTapped(object sender, Syncfusion.ListView.XForms.ItemTappedEventArgs e)
{
//Applying sorting to the underlying data when the header item is tapped.
if (e.ItemType == ItemType.Header && listView.IsStickyHeader)
{
listView.DataSource.SortDescriptors.Clear();
listView.DataSource.SortDescriptors.Add(new SortDescriptor()
{
PropertyName = "ContactName",
Direction = ListSortDirection.Ascending
});
}
}
Sort the items along with grouping
The SfListView
allows sorting the items along with grouping by adding the DataSource.GroupDescriptors and the DataSource.SortDescriptors with required property name.
Sorting with grouping by year
Sorting the items along with grouping by using KeySelector based on retuning the year value of the data-time property.
<ContentPage xmlns:syncfusion="clr-namespace:Syncfusion.ListView.XForms;assembly=Syncfusion.SfListView.XForms"
xmlns:data="clr-namespace:Syncfusion.DataSource;assembly=Syncfusion.DataSource.Portable">
<ContentPage.Content>
<syncfusion:SfListView x:Name="listView" ItemsSource="{Binding Items}" ItemSize="50">
<syncfusion:SfListView.GroupHeaderTemplate>
<DataTemplate>
<Grid>
<Label Text= "{Binding Key}" BackgroundColor="Teal" FontAttributes="Bold" TextColor="White"/>
</Grid>
</DataTemplate>
</syncfusion:SfListView.GroupHeaderTemplate>
</syncfusion:SfListView>
</ContentPage.Content>
</ContentPage>
var listView = new SfListView();
listView.ItemSize = 50;
listView.ItemsSource = viewModel.Items;
listView.GroupHeaderTemplate = new DataTemplate(() =>
{
var grid = new Grid();
var headerLabel = new Label
{
TextColor = Color.White,
FontAttributes = FontAttributes.Bold,
BackgroundColor=Color.Teal
};
headerLabel.SetBinding(Label.TextProperty, new Binding("key"));
grid.Children.Add(headerLabel);
return grid;
});
listView.DataSource.GroupDescriptors.Add(new GroupDescriptor()
{
PropertyName = "DateOfBirth",
KeySelector = (object obj1) =>
{
var item = (obj1 as Contacts);
return item.DateOfBirth.Year;
},
});
this.listView.DataSource.SortDescriptors.Add(new SortDescriptor()
{
PropertyName = "DateOfBirth",
Direction = ListSortDirection.Ascending
});
The following screenshot shows the output when items are sorted by year. Download the entire source code from GitHub here
Sorting with grouping by month and year
Sorting the items along with grouping by using KeySelector
based on returning the month and year value of the data-time property.
<ContentPage xmlns:syncfusion="clr-namespace:Syncfusion.ListView.XForms;assembly=Syncfusion.SfListView.XForms"
xmlns:data="clr-namespace:Syncfusion.DataSource;assembly=Syncfusion.DataSource.Portable">
<ContentPage.Content>
<syncfusion:SfListView x:Name="listView">
<syncfusion:SfListView.DataSource>
<data:DataSource>
<data:DataSource.GroupDescriptors>
<data:GroupDescriptor PropertyName="ContactName" />
</data:DataSource.GroupDescriptors>
<data:DataSource.SortDescriptors>
<data:SortDescriptor PropertyName="ContactName" Direction="Ascending"/>
</data:DataSource.SortDescriptors>
</data:DataSource>
</syncfusion:SfListView.DataSource>
</syncfusion:SfListView>
</ContentPage.Content>
</ContentPage>
public partial class MainPage : ContentPage
{
public MainPage()
{
InitializeComponent();
listView.DataSource.GroupDescriptors.Add(new GroupDescriptor()
{
PropertyName = "DateOfBirth",
KeySelector = (object obj1) =>
{
var item = (obj1 as Contacts);
return item.DateOfBirth.Month + "/" + item.DateOfBirth.Year;
},
Comparer = new CustomGroupComparer()
});
this.listView.DataSource.SortDescriptors.Add(new SortDescriptor()
{
PropertyName = "DateOfBirth",
Direction = ListSortDirection.Ascending
});
}
}
The following screenshot shows the output when items are sorted by month and year.
NOTE
You can refer to our Xamarin ListView feature tour page for its groundbreaking feature representations. You can also explore our Xamarin.Forms ListView example to know how to render set of data items with Xamarin.Forms views or custom templates.