Custom Sorting and Grouping in DataGrid Using Built-in UI in MAUI

Environment

Version	Product	Author
7.1.0	Telerik UI for .NET MAUI DataGrid	Dobrinka Yordanova

Description

When working with the Telerik DataGrid for MAUI, you might need to customize the sorting and grouping logic while still allowing users to utilize the built-in UI options for these operations. This involves overriding the default sort and group descriptors with custom logic.

This KB article also answers the following questions:

• How can I implement custom sorting in a DataGrid while using the built-in UI in MAUI?
• Is it possible to use delegate descriptors for custom grouping in the DataGrid with the default UI?
• How do I enable users to sort and group DataGrid columns using custom logic in MAUI?

Solution

To customize the sorting and grouping logic in a DataGrid while keeping the built-in UI functionality, follow these steps (the example uses the DataGridComboBoxColumn column):

1. Create a custom column class that inherits from DataGridComboBoxColumn.
2. Override the CreateSortDescriptor() and CreateGroupDescriptor() methods.
3. Implement your custom logic using DelegateSortDescriptor and DelegateGroupDescriptor.
4. Apply the custom column to the DataGrid control.

Below is a sample implementation:

public class CustomComboBoxColumn : DataGridComboBoxColumn
{
    protected override GroupDescriptorBase CreateGroupDescriptor()
    {
        // Implement your custom grouping logic here
        return new DelegateGroupDescriptor() { DisplayContent = "", KeyLookup = new CustomIKeyLookup() };
    }

    protected override SortDescriptorBase CreateSortDescriptor()
    {
        // Implement your custom sorting logic here
        return new DelegateSortDescriptor() { KeyLookup = new CustomSortKeyLookup(), Comparer = new CustomComparer() };
    }
}

Then, define the custom columns within your DataGrid control in XAML:

<telerik:RadDataGrid ItemsSource="{Binding ItemsSource}"
                     AutoGenerateColumns="False" UserEditMode="Cell"
                     UserGroupMode="Enabled">
    <telerik:RadDataGrid.Columns>
        <local:CustomComboBoxColumn HeaderText="Column 4"
                                    PropertyName="Column4"
                                    ItemDisplayBindingPath="Name"
                                    ItemsSource="{Binding PlanTypes}">
        </local:CustomComboBoxColumn>

        <local:CustomComboBoxColumn HeaderText="Column 5"
                                    PropertyName="Column5"
                                    ItemDisplayBindingPath="Name"
                                    ItemsSource="{Binding TypeRecords}">
        </local:CustomComboBoxColumn>
    </telerik:RadDataGrid.Columns>
</telerik:RadDataGrid>

This approach allows you to maintain the user-friendly features of the DataGrid, like sorting and grouping through the UI, while applying your specific logic for these operations.

See Also

• DataGrid Overview
• Grouping in DataGrid
• Sorting in DataGrid