LoadOnDemand Fires SelectionChanged

[Bruce]

I have several ListView's that are IsLoadOnDemandEnabled="True" and SelectionMode="Single".  In every case, touching "Load more items" fires a SelectionChanged event, unselecting any row that was set prior to loading more items.  This unselecting does not occur when SelectionMode="Multiple".  To make matters worse, the SelectionChange event fires before the LoadOnDemand event, giving me know way of interrupting the de-selection.

This makes no sense from a user's perspective.  Loading more records does not in any way imply that the currently-selected record(s) should be unselected.

I'm inclined to call this a pure bug, but I'm happy to hear your thoughts on the matter.

[Stefan Nenchev]

Hello, Bruce,

I have tested the scenario but could not reproduce the issue. I have tested the behavior with the LoadOnDemandEventAuto  as well as the LoadOnDemandManual examples from the SDK Samples Browser application(it can be found in the Examples/Forms folder of your local Telerik UI for Xamarin installation -- usually C:\Program Files (x86)\Progress\Telerik UI for Xamarin R1 2018\Examples\Forms). Would it be possible to provide more information on your exact setup so we can try reproducing the behavior and investigate it in more details? Is the issue reproducible on all platforms or just a single one is affected? You can consider raising a ticket(it would be great if you can attach a sample project that shows the undesired effects, you can modify some of the existing examples which I have referenced above) so that we provide you with more information as soon as possible.

Have a great rest of the week, Bruce.

Regards,
Stefan Nenchev
Progress Telerik

[Bruce]

I'll work on getting a sample project made and over to you.  Look for it later today.

[Bruce]

I was able to duplicate the problem.  I opened ticket 1160574 and attached my sample Solution to the ticket.

[Stefan Nenchev]

Hello, Bruce,

Thank you for providing the solution. As advised, the behavior indeed looks like a bug when using the LoadOnDemand Manual functionality in iOS. We are currently investigating the behavior. I will update the ticket and this thread once we have more information on the matter.

Regards,
Stefan Nenchev
Progress Telerik

[Bruce]

Good to hear.  I'll look for an update from you.

[Stefan Nenchev]

Hello, Bruce,

As discussed in the ticket, I can confirm that the behavior you have reported is a bug in the RadListView. You can track the issue on the following link from our Ideas & Feedback portal - ListView: [iOS]Clicking on LoadMore button throws SelectionChanged and clears the SelectedItem in some cases. I am here providing the information in case some other members are interested on the topic.

So basically, indeed the SelectionChanged event is thrown unnecessary in some cases. Аctually, if you have preset the SelectedItem and you click on the LoadMorebutton - the SelectedItem of the RadListView is lost. Testing the behavior, it seems that his is happening only the first time you click on the LoadMore button. From then on, the selected item is kept as it should be. With this in mind, I have attached a sample project which suggests a possible workaround of caching the selected item before calling the load on demand functionality only the first time.

Regards,
Stefan Nenchev
Progress Telerik