Mastering Xamarin.Forms - Second Edition

Creating a reverse visibility value converter

There are often cases where your user interface must wait for data to be loaded. In the meantime, the user might see what appears to be a broken or incomplete page. In these situations, it is best to let the user know what is happening by showing some sort of progress indicator and hiding the rest of the user interface, such as labels, until the data is ready.

Right now, our TripLog app uses only local data, so we do not really see any negative visual effects while the ViewModel data is loading. We will connect our app to a live API in the next chapter but, until then, we can simulate a waiting period by simply adding a three-second delay to our NewEntryViewModel ExecuteSaveCommand() method before ...