Group Order

[Joshua]

How can I specify the order in which groups are displayed in the RadListView? The control is automatically sorting my groups alphabetically (regardless of the order in which my items of a specific group are added to my collection), which I really don't want. In fact, my goal is to always have the groups in a specific order that cannot be re-ordered, and I want to specify this order explicitly. That is, it's not an ascending or descending order, but an arbitrary one that I specify.

Here's my XAML:

<telerikDataControls:RadListView x:Name="listView" ItemsSource="{Binding Path=Items}" ItemTemplateSelector="{StaticResource Key=itemDataSelector}" GroupHeaderTemplate="{StaticResource Key=headersTemplate}">
    <telerikDataControls:RadListView.GroupDescriptors>
        <telerikListView:PropertyGroupDescriptor PropertyName="Name"/>
    </telerikDataControls:RadListView.GroupDescriptors>
    <telerikDataControls:RadListView.HeaderTemplate>
        <DataTemplate>
            <Label Text="..."
                    FontSize="Title"
                    FontAttributes="Bold"
                    HorizontalOptions="Fill"
                    HorizontalTextAlignment="Center" />
        </DataTemplate>
    </telerikDataControls:RadListView.HeaderTemplate>
    <telerikDataControls:RadListView.FooterTemplate>
        <DataTemplate>
            <Label Text="..."
                    HorizontalOptions="Fill"
                    HorizontalTextAlignment="Center"/>
        </DataTemplate>
    </telerikDataControls:RadListView.FooterTemplate>
</telerikDataControls:RadListView>

 

I'm using Telerik UI for Xamarin 2020.1.218.1, Xamarin Forms 4.5.0.530.

[Didi]

Hi Joshua,

Thank you for the provided code.

The RadListView Grouping is alphabetically by default. In order to achieve non-alphabetically scenario you should use DelegateGroupDescripor and Converter. Please take a look at the attached project how the converter could be implemented. Note that it is up to you how the custom logic will be structured.

I hope the provided sample will help you get started with the scenario you want to achieve.

Regards,
Didi
Progress Telerik

[Joshua]

Hi Didi,

I was able to achieve custom sorting by providing a numeric key and using a ValueConverter in my binding to generate the headings (Label.Text) in my GroupHeaderTemplate, thank you for the suggestion and the example. I did not need to use a DelegateGroupDescriptor as I'm just grouping based off of the value of a single property (the Id of the group).

Regards,

Josh

[Paul Ridden]

Hi,

Is it possible to group by one property and then order on another?

I have groups of items which are for the same location however those groups then need to be in a certain order based on another property. Is this possible?

Kind regards,

Paul

[Paul Ridden]

I believe I have now implemented what I required, based on the sample posted above.