Mastering Xamarin.Forms - Second Edition

Updating DetailPage

Finally, we will need to update how the map on DetailPage is being bound to the data in the DetailViewModel. Since the ViewModel is being initialized via the navigation service now, it happens after the page is constructed, and therefore the map doesn't have the data it needs. Normally, this would not be a problem thanks to data binding; however, since the map control does not allow for data binding, we will need to handle its data differently. The best way for the page to check when its ViewModel has data for its map control is to handle the ViewModel's PropertyChanged event. If the ViewModel's Entry property changes, the map control should be updated accordingly, as shown in the following steps:

1. First, move the two ...