Improve Build Times with Visual Studio 2022

The Uno Platform template prior to Uno Platform 5.2 provides a cross-targeted Class library that includes multiple target frameworks, and your application may contain your own cross-targeted projects as well. This document explains how to make your builds faster.

Note

For projects created with Uno Platform 5.2 or later, the Uno.Sdk takes care of building appropriate target frameworks for the selected debugger target when starting a debugging session. Optionally, you can follow our migration guide to use the new project structure. If you want to always build one target framework you can follow the guide below.

Reduce the number of built TargetFrameworks (5.2 templates and later)

When using an Uno Platform 5.2 template or later, in the Folder Explorer, you can apply the following steps to build only a subset of target frameworks using a configuration file.

To do so:

Create a file named solution-config.props.sample next to your .sln file, with this content:

<Project>
    <!--
        This file is used to control the platforms compiled by Visual Studio, and allow for a faster
        build when testing for a single platform. This will also result in better intellisense, as
        the compiler will only load the assemblies for the platform that is being built. You do not
        need to use this when compiling from Visual Studio Code, the command line or other IDEs.

        Instructions:
        1) Copy this file and remove the ".sample" name
        2) Uncomment the single property below for the target you want to build
        3) Make sure to do a Rebuild, so that nuget restores the proper packages for the new target

        Notes:
        - You may optionally close the solution before making changes and reload the solution afterwards. This will avoid Visual Studio
        asking you to reload any projects, it will also ensure that the changes are picked up by Visual Studio, and trigger a restore of
        the packages.
        - You may want to unload the platform heads that you are not going to build for. This will ensure that Visual Studio does not
        try to build them, and will speed up the build process.
    -->

    <PropertyGroup>
        <!-- Uncomment each line for each platform that you want to build: -->

        <!-- <OverrideTargetFramework Condition="''!='hint: Windows App Sdk (WinUI)'">net8.0-windows10.0.19041.0</OverrideTargetFramework> -->
        <!-- <OverrideTargetFramework Condition="''!='hint: Webassembly'">net8.0-browserwasm</OverrideTargetFramework> -->
        <!-- <OverrideTargetFramework Condition="''!='hint: Desktop'">net8.0-desktop</OverrideTargetFramework> -->
        <!-- <OverrideTargetFramework Condition="''!='hint: iOS'">net8.0-ios</OverrideTargetFramework> -->
        <!-- <OverrideTargetFramework Condition="''!='hint: Android'">net8.0-android</OverrideTargetFramework> -->
        <!-- <OverrideTargetFramework Condition="''!='hint: MacCatalyst'">net8.0-maccatalyst</OverrideTargetFramework> -->
    </PropertyGroup>
</Project>

Make sure to replace net8.0 and -windows10.0.19041.0 with the appropriate version from your .csproj project.

You can commit solution-config.props.sample to your source control.
Next, make a copy of solution-config.props.sample to solution-config.props. This file is automatically loaded by the Uno.Sdk.
If you're using git, add this solution-config.props to your .gitignore.

Note

This avoids altering the target frameworks or your own CI, as well as other clones made by other developers.
Follow the directives from the file, uncommenting one of the OverrideTargetFramework to your choosing.
In the project head, as well as any other libraries using the Sdk="Uno.Sdk", add the following block immediately below the last <TargetFrameworks> line:
```
<TargetFrameworks Condition=" '$(OverrideTargetFramework)' != '' ">$(OverrideTargetFramework)</TargetFrameworks>
```
Once done, if you're in Visual Studio 2022, you may need to close and re-open your solution or otherwise click the reload button. For other IDEs, the projects will reload automatically.

At this point, you'll notice that the list of target frameworks available in the debugger will have been reduced to the list you added in OverrideTargetFramework.

Improve performance using the Uno Platform templates (5.1 and earlier)

When using an Uno Platform 5.0 template, in the Solution Explorer, you'll find a folder named Solution Items, and a file named solution-config.props.sample.

You can follow the directions specified in this file, or follow them here:

Right-click on the root item (your solution name) and Open in file explorer
Locate the solution-config.props.sample and make a copy named solution-config.props in the same folder
Back in Visual Studio, and for your convenience you can right-click on Solution Items and add solution-config.props

Now that we have configured this file, let's say that you want to debug for WebAssembly:

In the solution-config.props file, uncomment the line that mentions Wasm or WebAssembly then save it.
For the change to take effect, close and reopen the solution, or restart Visual Studio.

Repeat this process when changing your active development platform.

Note

The solution-config.props is automatically included in a .gitignore file to avoid having your CI environment build only for one target.

Cross-targeted library builds in Visual Studio

While building with the command line dotnet build -f net7.0-ios only builds the application's head and the class library for net7.0-ios, as of Visual Studio 17.8, class library builds are considering all target frameworks, regardless of the project head's target framework being built. (Please help the Uno Platform community by upvoting the issue!)

Considering that during development, it is common to work on a single platform at a given time, the two sections below contain a suggested set of changes to the Uno Platform solution that can be performed on the solution to restrict the active build platform, and therefore significantly speed up build times and make intellisense respond faster.

Choose the section covering your cases, whether you're using a solution built using Uno Platform 5.0 templates or created with an earlier version.

Improve your own solution (4.9 and earlier)

If you created your solution with an earlier version of Uno Platform, you can make some modifications to make your build faster:

Let's create a set of solution filters to ensure that individual project heads can be loaded:
1. Create a new app template with iOS, Android, WebAssembly and Windows targets selected.
2. Right click on the .Mobile and .Wasm projects and select Unload Project
3. On the top level Solution node, right-click to select Save As Solution Filter, name the filter MyApp-Windows-Only.slnf
4. Right-click on the Mobile project, select Reload Project
5. Unload the .Windows project, then save a new solution filter called MyApp-Mobile-Only.slnf
6. Repeat the operation with the .Wasm project, with a solution filter called MyApp-Wasm-Only.slnf
These solution filters will prevent Visual Studio to restore NuGet packages for TargetFrameworks that will be ignored by the configuration done below.

Now, next to the solution file, create a file named targetframework-override.props:

<Project>
    <Import Project="solution-config.props" Condition="exists('solution-config.props')" />

    <!-- Override the TargetFrameworks list with the one specified in MyAppTargetFrameworkOverride -->
    <PropertyGroup Condition="'$(MyAppTargetFrameworkOverride)'!=''">
        <TargetFrameworks>$(MyAppTargetFrameworkOverride)</TargetFrameworks>
    </PropertyGroup>
</Project>

Also next to the solution file, create a file named solution-config.props.sample:

<Project>
    <PropertyGroup>
        <!--
        Uncomment the following line to enable single-target framework builds
        in order to get faster performance when debugging for a single platform.

        Once this file is modified, use the appropriate solution filter to avoid
        NuGet restore issues.

        Available target frameworks can be found in the project heads of your solution.
        -->
        <!-- <MyAppTargetFrameworkOverride>net7.0-ios</MyAppTargetFrameworkOverride> -->
    </PropertyGroup>
</Project>

Next, in all projects of the solution which are cross-targeted (with multiple TargetFrameworks values), add the following lines right after the PropertyGroup which defines <TargetFrameworks>:

<!-- Import the TargetFramework override configuration -->
<Import Project="../../targetframework-override.props" />

The file should then look like this:

<Project Sdk="Microsoft.NET.Sdk">
    <PropertyGroup>
        <TargetFrameworks>net7.0-windows10.0.19041;net7.0;net7.0-ios;net7.0-android</TargetFrameworks>
    </PropertyGroup>
</Project>
<!-- Import the TargetFramework override configuration -->
<Import Project="../../targetframework-override.props" />

Note

If the template is created with dotnet new, the path will instead be ../targetframework-override.props

Create a copy of the file solution-config.props.sample next to itself, and name it solution-config.props
If using git, add this specific file to the .gitignore so it never gets committed. This way, each developer can keep their own version of the file without corrupting the repository.
Commit your changes to the repository.

At this point, your solution is ready for single-TargetFramework use.

For example, to work on net7.0-ios:

Before opening the solution, open the solution-config.props file and uncomment MyAppTargetFrameworkOverride to contain net7.0-ios
Open the MyApp-Mobile-Only.slnf solution filter in Visual Studio 2022
You should only see the .Mobile and Class Library projects in your solution
When building and debugging the app, you'll only now build for the target specified in solution-config.props.

Important

When changing the MyAppTargetFrameworkOverride value, make sure to close the solution and reload it so the build system recognizes properly the change.