listview binding images with url crashes

Hi everyone,

i couldnt find my specific problem at forums' posts,
so i want to ask that,

i only have a listview component in a page,
like that :

<br /> <ListView x:Name="SeparatorListView" SeparatorColor="Transparent" ItemsSource="{Binding JobApplications}" Margin="0,0,0,0" RowHeight="100" HorizontalOptions="FillAndExpand" VerticalOptions="FillAndExpand" BackgroundColor="White" CachingStrategy="RecycleElement"><br /> &lt;ListView.ItemTemplate><br /> <DataTemplate><br /> <ImageCell Height="80" Text="{Binding Applicant.FullName}" Detail="{Binding Position.PositionName}" ImageSource="{Binding Photo.Url}"/><br /> </DataTemplate><br /> &lt;/ListView.ItemTemplate><br /> </ListView><br />

and i bind the bindingcontext in onappearing method

protected async override void OnAppearing()
{
BindingContext = this;
base.OnAppearing();
var result = await HttpServices.JobApplicationService.GetApproveList();
JobApplications = new ObservableCollection(result);
}

and when i opened that page , app crashes suddenly.
is there any known development step to fix that ?