Bind Command to a template view from viewmodel xamarin prism - xamarin

Question

I use prism on the project. My problem is: i have a View OrdemServicoView and a model OrdemServicoViewModel, OrdemServicoView has a syncfusion list... inside has a DataTemplate with a some propertys pass and i can bind, but when i try use command inside template it doesnt work, the command code is in OrdemServicoViewModel... how can i do that?
OrdemServicoViewModel:
public DelegateCommand<object> ItemSelectedCommand { get; set; }
OrdemServicoView (List):
<syncfusion:SfListView.ItemTemplate>
<DataTemplate>
<templates:OrdemServicoCardView />
</DataTemplate>
</syncfusion:SfListView.ItemTemplate>
In OrdemServicoCardView i try to make a button with ItemSelectedCommand binded

Answer 1

The problem you are having has to do with Binding Context. For instance normally within your View your BindingContext is your ViewModel. When working with a DataTemplate inside of something like a ListView your BindingContext is instead whatever data model you may be passing to that ListView as the ItemsSource. The trick therefore is to be able to reference back to the original ViewModel.
<syncfusion:SfListView.ItemTemplate x:Name="lv">
<DataTemplate>
<Button Text="Some Button"
Command="{Binding BindingContext.MyCommand,Source={x:Reference lv}}" />
</DataTemplate>
</syncfusion:SfListView.ItemTemplate>
How we do it is rather simple, first you need to provide a name on an element that has our ViewModel as it's Binding Context. You can pick anything you like really, I usually just reference the Parent Page but the actual List View will work just fine as well. Next we need to add that named element as the Binding Source. Finally we need to realize our new Binding Context is the Element we added as the Source, so we must prepend our Binding with the BindingContext property to have the proper scope into our ViewModel.