Sorting

The DataGrid provides a built-in sorting functionality which allows the user to order the view of the data the control represents. Sorting the control is possible both through the UI and programmatically.

Sorting through the UI

• Sort through the UI by clicking or tapping the column header. UserSortMode defines how user input (column header tap/click) affects the current sort state of the grid. The available options are Auto, Multiple, None, and Single. The default value of the UserSortMode is Auto.

The CanUserSort (bool) property is used to enable or disable the sorting of a specific column. It defines a value indicating whether the user can sort the data by the values in the column.

Programmatic Sorting

The DataGrid provides two ways of programmatic sorting:

• By a property with a PropertySortDescriptor
• By a custom key with a DelegateSortDescriptor

Property Sort Descriptor

You can sort the data in a DataGrid by pointing a property from the class that defines your objects. This can be achieved with a PropertySortDescriptor and setting its PropertyName property. The descriptor exposes the following important properties:

• PropertyName—Gets or sets the name of the property that is used to retrieve the key to sort by.
• SortOrder—Gets or sets the order of the sorting (ascending or descending).

<telerikDataGrid:RadDataGrid.SortDescriptors>
    <telerikCommon:PropertySortDescriptor PropertyName="Name"/>
</telerikDataGrid:RadDataGrid.SortDescriptors>

In the example, the used namespaces are defined like this:

xmlns:telerikDataGrid="clr-namespace:Telerik.XamarinForms.DataGrid;assembly=Telerik.Maui.Controls.Compatibility"
xmlns:telerikCommon="clr-namespace:Telerik.XamarinForms.Common.Data;assembly=Telerik.Maui.Controls.Compatibility"

Delegate Sort Descriptor

The difference between the DelegateSortDescriptor and the PropertySortDescriptor is that the DelegateSortDescriptor sorts data by a custom key, while the PropertySortDescriptor sorts by a defined key, which is a property from the model.

It exposes the following properties:

• KeyLookup—Gets or sets the IKeyLookup instance that is used to retrieve the sort key for each data item.
• SortOrder—Gets or sets the order of the sorting (ascending or descending).

To use a DelegateSortDescriptor, you need to create a class that implements the IKeyLookup interface which will return the key by which you want to sort. Then, you need to add the DelegateSortDescriptor to the RadDataGrid.SortDescriptors collection and set its KeyLookUp property.

The following example demonstrates a custom IKeyLookup implementation.

public class CustomIKeyLookup : IKeyLookup
{
    public object GetKey(object instance)
    {
        return (instance as Club).Name.Length;
    }
}

Add it to the GroupDescriptors collection of the DataGrid:

this.dataGrid.SortDescriptors.Add(new DelegateSortDescriptor() { KeyLookup = new CustomIKeyLookup()});

Here is how the DataGrid looks when sorting is applied:

See Also

• Columns
• Grouping
• Filtering
• Selection