UI gets stuck while loading lot of data from realm - xamarin

Question

I am trying to show 10,000 contacts on listview in xamarin forms using realm. But whenever user traverse to contact listing screen
it gets freezed and loads after a while.
Moreover , i have provided an option to search from list as well and that too gets stuck as search if performing on UI thread.
Following is the code to load data from realm
public override async Task Initialize(Object data )
{
private Realm _realmInstance = getRealm();
if (contactList != null)
{
contactList.Clear();
}
contactList = _realmInstance.All<Contact>().OrderByDescending(d => d.contactId).ToList();
// here the binding happens with realm data
contacts = new ObservableCollectionFast<Contact>(contactList);
}
public ObservableCollectionFast<Contact> contacts
{
get { return items; }
set
{
items = value;
OnPropertyChanged("contacts");
}
}
as it was taking time in loading i thought to fetch realm data in background and bind it on UI thread as follows
but that is throwing error
realm accessed from incorrect thread
await Task.Run(() => {
contactList = _realmInstance.All<Contact>().OrderByDescending(d => d.contactId).ToList();
});
if (contactList.Count() > 0)
{
ContactListView = true;
AddContactMsg = false;
}
else
{
AddContactMsg = true;
}
Device.BeginInvokeOnMainThread(() =>
{
contacts = new ObservableCollectionFast<Contact>(contactList);
});
i wanted to try limiting the results by using TAKE function of LINQ but unfortunately its not supported by realm yet. not sure how i can smoothly load records from realm to listview.
EDIT
as per the SushiHangover i have changed things from IList to IQueryable
public IQueryable<Contact> contacts
{
get { return items; }
set
{
items = value;
OnPropertyChanged("contacts");
}
}
public override async Task Initialize(Object data )
{
_realmInstance = getRealm();
contacts = dbContactList= _realmInstance.All<Contact>();
}
so far search is working pretty smoothly but IQueryable change leads to another issue. on repeatedly performing following steps results in app crash
tap on list item
detail page gets open then press back
scroll down to few records
perform step 1 and repeat
this results into stackoverflow error
04-19 06:05:13.980 F/art ( 3943): art/runtime/runtime.cc:289]
Pending exception java.lang.StackOverflowError thrown by 'void
md5b60ffeb829f638581ab2bb9b1a7f4f3f.CellAdapter.n_onItemClick(android.widget.AdapterView,
android.view.View, int, long):-2' 04-19 06:05:13.980 F/art (
3943): art/runtime/runtime.cc:289] java.lang.StackOverflowError: stack
size 8MB
Link to entire log file
code to fire item click command is
public ICommand OnContactSelectCommand => new Command<Contact>(OnContactSelect);
following code will open ups a detail page
private async void OnContactSelect(Contact contact)
{
if (contact != null)
{
await NavigationService.NavigateToAsync<ContactDetailViewModel>(contact.mContactId);
}
}
Note:
when i replace IQueryable with List i do not face any error
somehow my issue is related to realm github thread where user is getting exception on listView.SelectedItem = null while using IQueryable
here is my code of list view item tap
private static void ListViewOnItemTapped(object sender, ItemTappedEventArgs e)
{
var listView = sender as ListView;
if (listView != null && listView.IsEnabled && !listView.IsRefreshing)
{
// have commented this line because it was crashing the app
//listView.SelectedItem = null;
var command = GetItemTappedCommand(listView);
if (command != null && command.CanExecute(e.Item))
{
command.Execute(e.Item);
}
}
}