Tag Archives: maui

.net, microsoft, mobile, Notes from the field, professional, software development, tech

First steps with MAUI: some friction

I am evaluating Microsoft’s MAUI (Multi-platform app UI) for use on a cross-platform project. I mainly develop on a Mac with Visual Studio Code.

Setup for MAUI development is well explained here though getting everything in place for Mac Catalyst, iOS and Android is tedious. There is a tricky issue related to Apple’s Xcode, needed for MAUI for the Apple targets. Apple’s recommendation is that you install Xcode from the App Store. As you would expect, it updates quite frequently and always when there is a new version of macOS. The version on my machine is therefore 26.6. After installing MAUI for .NET 10 I got an error when trying to build, stating that I had the wrong version (mine was too new).

The workaround for this is either to install multiple versions of Xcode, which is fiddly, or to set ValidateXcodeVersion to false in the .csproj project file.

As it turns out, there is another fix. The .NET for iOS SDK (used by MAUI) was updated last month to require Xcode 26.6. Note: require, not support. Each version of the SDK requires one and only one version of Xcode, and there is a lag between Apple releasing a new version, and Microsoft updating its SDKs.

My instinct is to set ValidateXcodeVersion false during development and to watch out for strange errors that might be fixed for a production build, using the correct Xcode version.

Microsoft’s MAUI SDK engineering lead said:

Updates can include different things that amount to varying levels of work. Sometimes there’s api changes in the SDKs Xcode ships that we need to account for, sometimes they change Cli tools or break things in other ways. Depending on the changes it can be a little bit of work or a lot. 

Lately minor version updates to Xcode tend to be somewhat compatible with existing MAUI (Mac/ios) workloads and you can technically force trying to use it with the right build settings, but we generally advise not installing Xcode from the App Store so that it isn’t silently updated and you can install updates when you know they’ll be supported by MAUI instead.

This is friction, though it comes with the cross-platform territory. Note that Apple insists on building with the latest Xcode for store submission.

With that out of the say, I started building an experimental app. This is not Windows and conceptually one should think of the app UI as a single page, mobile app style, even if developing for Windows and Mac Catalyst. I decided to use a Tab Bar for navigation, but ran into an issue: when debugging the app for Mac Catalyst, the Tab Bar did not appear.

I thought this was something I was doing wrong, even though it was a simple and basic case. Then after digging a bit I discovered that it was a bug, that I was not the first to hit it, and that it was fixed with a workaround late last year.

The solution is to run: dotnet workload update from the command line to get the latest version.

Both issues are a reminder of how tricksy cross-platform development can be, particularly for frameworks like MAUI which use native widgets rather then drawing them from scratch like Flutter or Avalonia UI.

The solution, it seems to me, is to keep the user interface simple.

microsoft, mobile, mono, software development, tech

No Mono in Microsoft’s cross-platform MAUI framework on .NET 11 – and a quick hands-on

Microsoft has released preview 6 of .NET 11, for which release is expected in November, including a big change to MAUI (Multi-platform App UI): it now runs only on .NET Core, rather than the Mono runtime.

Principal product manager David Ortinau reports that “your app builds and runs on CoreCLR, the same runtime behind ASP.NET Core, your cloud services, and desktop .NET.”

According to Ortinau, performance is generally faster than Mono on iOS and Mac Catalyst. The implication is that it is slower on Android, though he does say that it is within 10% on startup and app size. Selecting Mono is no longer an option, and the only use of Mono in .NET 11 is for Blazor WebAssembly.

There is a key remark in Ortinau’s post. “We have worked closely with first party .NET MAUI apps validating our progress, and have received feedback from several others,” he says. The question developers may ask: what first party .NET MAUI apps? Microsoft does not use MAUI for its well-known cross-platform apps such as Teams or Office. In 2023, the company said it uses MAUI for its 365 admin, Azure admin and Store Commerce apps, though I do not know if this is still the case.

Slide from .NET Conf 2023 showing some limited use of MAUI at Microsoft

Developers would have more confidence in MAUI, both for its quality and its long-term future, if Microsoft itself made more use of it.

That said, the company does seem to be putting substantial effort into MAUI for .NET 11. Along with the CoreCLR work there are other updates in this preview. Microsoft states that the focus in .NET 11 is “to improve product quality” and this is something developers will be happy about; in some cases a statement like this might imply neglect but for MAUI it is exactly what is needed.

I have a demo MAUI project and decided to upgrade it to the new preview, working with Visual Studio Code on a Mac. It was not as easy as I had hoped. The process involved not only updating the target framework, but also the minimum versions of Android, iOS and Mac Catalyst. Then the Android SDK had to be updated, with an annoyance related to the recommended:

dotnet build -t:InstallAndroidDependencies -f net11.0-android “-p:AndroidSdkDirectory=[your path to the Android SDKs]”

The command failed with an error about the Android SDK licenses not being accepted. The fix is to set an environment variable:

export AcceptAndroidSDKLicenses=True

and then it works, though I’m not sure how this satisfies the lawyers. I also had an error where

builder.Logging.AddDebug();

could not find the AddDebug method; the fix was to add a package reference to Microsoft.Extensions.Logging.Debug to the .csproj file.

With all that done, the “Start debugging” command is not working for me in VS Code. I get a message that the “configured debug type ‘coreclr_mobile’ is not supported, and an instruction to install coreclr_mobile Extension; clicking this button gets me “no extensions found.” Update – this was resolved after updating both the C# and C# Dev Kit extensions to pre-release versions (.NET MAUI was already pre-release).

However, dotnet run from the command line works:

Demo of MAUI using .NET 11 Preview 6 on a Mac

I plan to do some more experimentation; note that this is a preview of .NET so some friction is expected.