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.
Let’s pick up where we left off in the previous blog post, but it is time to clean up the app to use MVVM. First step: create a ViewModel folder and in that put two files:
I’m going to start off where we were at the end of Part 5, but this time instead of creating two labels (for State and Zip) I’m going to create one label with MultiBinding:
This is more efficient and also allows me to put VerticalOptions=”Center” into the label tag and have it affect all the contained labels. This is a nice alternative to having to use the HorizontalStackLayout
NB: You can continue to use the Xamarin.Forms <StackLayout> element, but HorizontalStackLayout and VerticalStackLayout have been optimized and thus are preferred.
When last we looked, we were returning a few countries. Let’s use ZipWise’s ability to look up a city name and give us all the info about all matching cities. We’ll then have fun with displaying that info.
When I ask for all cities named Middletown I get a nice set of results
I’ll leave it to you to put this into Json Prettifier as the result is pretty long for a blog post. We do, now, have a nice list of cities we can display, along with their states and zip codes.
We’ve seen how to get a single zip code and display it in a series of labels. Let’s use a collection to take a look at how we might deal with that in MAUI. To get started, we’ll create a new MAUI application named MultipleZip. Throw away what is in MainPage.xaml and MainPage.xaml.cs. You should have a nice clean slate.
As you can see there are three attributes: the Title, the ContentTemplate and the Route. The interesting ones are the latter two. We’ll talk about ContentTemplate in a bit. The Route speaks to the way navigation is performed in MAUI, and that is (surprise!) by using “routes” (you can think of them as URIs.) In this case, the Route couldn’t be simpler: we’re going directly to MainPage.
Let’s turn to MainPage. We’re going to start by noting that MainPage is a contentPage – the most common sort of page for MAUI. You can add controls, but like in Xamarin.Forms the page can only have one control, but of course layout controls can have child controls, so that is not burdensome.
As noted in part 0, I assume you are a Xamarin.Forms/C# programmer, familiar with Visual Studio. This series is not about converting your existing Xamarin.Forms apps; rather it is about converting your brain to MAUI. Since I’m learning as I’m going, your mileage may vary.
Community Toolkit
One of the tools you’ll absolutely want is the .NET Community Toolkit. It is available as an open-source project on GitHub. There are all sorts of goodies in there and you may want to take the time, at least, to read the Read.me file.
As noted in part 0, I assume you are a Xamarin.Forms/C# programmer, familiar with Visual Studio. This series is not about converting your existing Xamarin.Forms apps; rather it is about converting your brain to MAUI. Since I’m learning as I’m going, your mileage may vary.
To get started, install the preview edition of Visual Studio 2022 (that may not be necessary by the time you’re reading this) which fully supports MAUI. Next, create a new project. We’ll call it ZipCodeFinder because we’ll be using the web service ZipWise which is free for limited use (which is all we’ll need).
Open VS, create a new project, and choose the .NET MAUI app template:
All In One Project
Notice that the entire solution is now in one project. You could make the argument either way for this design, but this is what Microsoft decided, so let’s go with that.
I’m going to start a serious attempt to upgrade my skills from Xamarin.Forms to Maui. I’m not sure how difficult this will be, but I’m starting with James Montemagno’s excellent video/code course for beginners.
Unfortunate for me, and perhaps for you, is that his course is targeted at people new to Xamarin, Xaml, etc. In the following posts, which will come out sporadically, I will target my work towards intermediate and expert Xamarin.Forms programmers. That is I’ll assume you know and have experience with
Xamarin.Forms
Xaml
C# 7 or later
Since I’m really learning this myself, these will not come out on any strict cadence, but only as I learn something new. I will do everything I can to make sure what I provide is accurate, but let me know if I’ve done something dumb.
All the code will, of course, be publicly available on github.
Posted inC#, Maui|TaggedLearning Maui|Comments Off on Learning .Net Maui – Posting 0
Incredibly pleased to have one of the pioneers in Agile programming: Robert “Uncle Bob” Martin.
Uncle Bob is known for, among other things, his SOLID principles of development. He is the author of the seminal book Clean Code along with Clean Coder and one of my new favorites Clean Agile.
1995. Designing Object-Oriented C++ Applications Using the Booch Method. Prentice Hall. ISBN978-0132038379.
2002. Agile Software Development, Principles, Patterns, and Practices. Pearson. ISBN978-0135974445.
2009. Clean Code: A Handbook of Agile Software Craftsmanship. Prentice Hall. ISBN978-0132350884.
2011. The Clean Coder: A Code Of Conduct For Professional Programmers. Prentice Hall. ISBN978-0137081073.
2017. Clean Architecture: A Craftsman’s Guide to Software Structure and Design. Prentice Hall. ISBN978-0134494166.
I expect most people my age have had great ideas they never patented. I’ll list a few here just to make myself feel better and to encourage you to post yours (these are ideas that are already patented or can’t be)
30 years ago when we got our puppy I put up some bells on the door and taught him that ringing the bells means we’ll take him out. He never abused the privilege. Now, doggy bells are every where.
My best invention was 25 years ago. I suggested to the people I was working with that we create a drop down button. The idea was a button with an arrow next to it. You click the arrow and a small menu appears. Whatever you pick from the menu appears as the text of the button, and clicking the button takes that action. Woe is me, it is everywhere today.
Also about 25 years ago I conceived of Quake Awake — I had read that people who awaken at the beginning of an earth quake are likelier to survive than those who sleep through: hence: Quake Awake. It would look like a smoke detector, and you could set the sensitivity, the necessary duration of quaking, the times of day (if you only want it to go off if you are sleeping) and etc. I even had a patent lawyer tell me it was a great idea. Woe is me, you could now write that as an app in about 4 hours.
