It depends on you, they all can achieve the effect.
However if you want to reduce the CPU consumption of the program, then don't use the onAppearing
method too much to refresh the page data.
Another method is that you can change the data of the model through Delegate/Event/MessageCenter.
You can refer to this discussion to know how to use Delegate/Event/MessageCenter.
Here I will give the sample by using MessageCenter to achieve that.
For example, the TestViewModel as follows:
public class TestViewModel : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
protected virtual void NotifyPropertyChanged([CallerMemberName] string propertyName = "")
{
PropertyChanged?.Invoke(this, new PropertyChangedEventArgs(propertyName));
}
private string pagetitle;
public string PageTitle
{
get
{
return pagetitle;
}
set
{
if (pagetitle != value)
{
pagetitle = value;
NotifyPropertyChanged();
}
}
}
}
Then bind it in FirstPage as follows, and Subscribe MessageCenter inside it:
TestViewModel testViewModel = new TestViewModel();
BindingContext = testViewModel;
MessagingCenter.Subscribe<object>(this, "Hi", (sender) =>
{
// Do something whenever the "Hi" message is received
testViewModel.PageTitle = "Modified Title";
});
Then in the SecondPage, when changing the data by sending message. When back to FirstPage, the View Will be updated.
private void Button_Clicked(object sender, EventArgs e)
{
MessagingCenter.Send<object>(this, "Hi");
}