Busy week, so this one will be short. I’ve taken the code from Part 7 and copied it into Part 8. The source for 8 is here. So, what’s new?
The most important improvement in 8 is the addition of Community Toolkit for Maui and the Microsoft toolkit for MVVM. Open your “Manage NuGet Packages” window and check that you have or add these packages
- CommunityToolkit.Maui
- CommunityToolkit.Maui.Core
- Microsoft.MauiDependencies
- Microsoft.Maui.Extensions
- Microsoft.Toolkit.Mvvm
This allows you to make some magic. The most impressive of which is how much code you will no longer have to write, because the MVVM kit provides code generators. We’ll see a lot more of this as we go, but let’s get started by making some changes.
ObservableObject
The first thing we’ll do is delete ViewModelBase! We won’t need it anymore as we’ll have MainViewModel inherit from ObservableObject. This provides two things: a generic implementation of OnNotifyChanged and also OnNotifyChanging which can be very useful.
ObservableProperty
Look at your ResultList property. Lots of boilerplate code. Delete everything except the backing variable, and just above that add the attribute ObservableProperty
[ObservableProperty]
private List<Result> _resultList;
That’s it. The toolkit will generate the property for you. You can work exactly as if you had implemented the property yourself. For example, we can use the (generated) property like this:
ResultList = new List<Result>();(For those of you who are curious about how this is done, take a look at this article).
Usings and namespaces…
Intellisense will fix up your using statements, but the ones you’ll need so far are
using CommunityToolkit.Maui;
using Microsoft.Toolkit.Mvvm;
using Microsoft.Toolkit.Mvvm.ComponentModel;
Truth is, you only need the last for this example, but you’ll need the others soon.
In the XAML you’ll want to use this namespace
xmlns:toolkit="http://schemas.microsoft.com/dotnet/2022/maui/toolkit"Your program should continue to work as intended.
More soon.
Caveat Emptor… As noted in the first of this series, I’m learning as I write. I’ll correct things that were initially incorrect, but your mileage may vary.
Comments: The best way to send comments, and especially corrections is to send email to jesseliberty@gmail.com. Thanks!
