[Dev][Build] VS 2026 Support (#44304)

<!-- Enter a brief description/summary of your PR here. What does it
fix/what does it change/how was it tested (even manually, if necessary)?
-->
## Summary of the Pull Request
This PR updates the PowerToys solution to support **Visual Studio 2026
(PlatformToolset v145)**. It centralizes the build configuration,
updates the C++ language standards, and fixes an issue with a MouseJump
unit test that appears while using the VS 2026 supported build agent.

<!-- Please review the items on the PR checklist before submitting-->
## PR Checklist

- [ ] Closes: #xxx
- [x] **Communication:** I've discussed this with core contributors
already. If the work hasn't been agreed, this work might be rejected
- [x] **Tests:** Added/updated and all pass
- [ ] **Localization:** All end-user-facing strings can be localized
- [x] **Dev docs:** Added/updated
- [ ] **New binaries:** Added on the required places
- [ ] [JSON for
signing](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ESRPSigning_core.json)
for new binaries
- [ ] [WXS for
installer](https://github.com/microsoft/PowerToys/blob/main/installer/PowerToysSetup/Product.wxs)
for new binaries and localization folder
- [ ] [YML for CI
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/ci/templates/build-powertoys-steps.yml)
for new test projects
- [ ] [YML for signed
pipeline](https://github.com/microsoft/PowerToys/blob/main/.pipelines/release.yml)
- [ ] **Documentation updated:** If checked, please file a pull request
on [our docs
repo](https://github.com/MicrosoftDocs/windows-uwp/tree/docs/hub/powertoys)
and link it here: #xxx

<!-- Provide a more detailed description of the PR, other things fixed,
or any additional comments/features here -->
## Detailed Description of the Pull Request / Additional comments

**Build System & Configuration:**
- Updated `Cpp.Build.props` to use `v145` (VS 2026) as the default
`PlatformToolset`, with fall back to `v143` for VS 2022.
- Configured C++ Language Standard:
  - `stdcpplatest` for production projects.
- Removed explicit `<PlatformToolset>` definitions from individual
project files (approx. 37 modules) to inherit correctly from the central
`Cpp.Build.props`.

**Code Refactoring & Fixes:**
- Updated `DrawingHelperTests.cs` in MouseJump Unit Test to ease the
pixel difference tolerance. This became an issue after switching to the
new VS2026 build agent.
<!-- Describe how you validated the behavior. Add automated tests
wherever possible, but list manual validation steps taken as well -->
## Validation Steps Performed

- Validated successful compilation of the entire solution. Similar
updates have been made to the .NET 10 branch, but these are much cleaner
and will be merged into that branch once fully confirmed working.

---------

Co-authored-by: Kai Tao (from Dev Box) <kaitao@microsoft.com>
Co-authored-by: Gordon Lam (SH) <yeelam@microsoft.com>

.pipelines/v2/oneFuzz.yml

@@ -35,7 +35,9 @@ stages:
             ${{ else }}:
               name: SHINE-OSS-L
             ${{ if eq(parameters.useVSPreview, true) }}:
-              demands: ImageOverride -equals SHINE-VS17-Preview
+              demands: ImageOverride -equals SHINE-VS18-Preview
+            ${{ else }}:
+              demands: ImageOverride -equals SHINE-VS18-Latest
           buildPlatforms:
             - ${{ parameters.platform }}
           buildConfigurations: [Release]

.pipelines/v2/release.yml

@@ -51,7 +51,9 @@ extends:
     pool:
       name: SHINE-INT-S
       ${{ if eq(parameters.useVSPreview, true) }}:
-        demands: ImageOverride -equals SHINE-VS17-Preview
+        demands: ImageOverride -equals SHINE-VS18-Preview
+      ${{ else }}:
+        demands: ImageOverride -equals SHINE-VS18-Latest
       os: windows
     sdl:
       tsa:
@@ -74,7 +76,9 @@ extends:
                 demands:
                   # Our INT agents have a large disk mounted at P:\
                   - ${{ if eq(parameters.useVSPreview, true) }}:
-                    - ImageOverride -equals SHINE-VS17-Preview
+                    - ImageOverride -equals SHINE-VS18-Latest-Preview
+                  - ${{ else }}:
+                    - ImageOverride -equals SHINE-VS18-Latest
                 os: windows
               variables:
                 IsPipeline: 1 # The installer uses this to detect whether it should pick up localizations

.pipelines/v2/templates/job-build-project.yml

@@ -253,7 +253,7 @@ jobs:
       displayName: Build PowerToys main project
     inputs:
       solution: 'PowerToys.slnx'
-      vsVersion: 17.0
+      vsVersion: 18.0
       msbuildArgs: >-
         -restore -graph
         /p:RestorePackagesConfig=true
@@ -276,7 +276,7 @@ jobs:
     condition: and(succeeded(), eq(variables['BuildPlatform'], 'arm64'))
     inputs:
       solution: PowerToys.slnx
-      vsVersion: 17.0
+      vsVersion: 18.0
       msbuildArgs: >-
         -restore
         /p:Configuration=$(BuildConfiguration)
@@ -338,7 +338,7 @@ jobs:
     displayName: Build BugReportTool
     inputs:
       solution: '**/tools/BugReportTool/BugReportTool.sln'
-      vsVersion: 17.0
+      vsVersion: 18.0
       msbuildArgs: >-
         -restore -graph
         /p:RestorePackagesConfig=true
@@ -359,7 +359,7 @@ jobs:
     displayName: Build StylesReportTool
     inputs:
       solution: '**/tools/StylesReportTool/StylesReportTool.sln'
-      vsVersion: 17.0
+      vsVersion: 18.0
       msbuildArgs: >-
         -restore -graph
         /p:RestorePackagesConfig=true
@@ -381,7 +381,7 @@ jobs:
       displayName: Publish ${{ project }} for Packaging
       inputs:
         solution: ${{ project }}
-        vsVersion: 17.0
+        vsVersion: 18.0
         msbuildArgs: >-
           /target:Publish
           /graph

.pipelines/v2/templates/job-build-ui-tests.yml

@@ -82,7 +82,7 @@ jobs:
       displayName: Build UI Test Projects
       inputs:
         solution: '**/*UITest*.csproj'
-        vsVersion: 17.0
+        vsVersion: 18.0
         msbuildArgs: >-
           -restore
           -graph
@@ -103,7 +103,7 @@ jobs:
         displayName: 'Build UI Test Module: ${{ module }}'
         inputs:
           solution: '**/*${{ module }}*.csproj'
-          vsVersion: 17.0
+          vsVersion: 18.0
           msbuildArgs: >-
             -restore
             -graph

.pipelines/v2/templates/pipeline-ci-build.yml

@@ -49,7 +49,9 @@ stages:
               ${{ else }}:
                 name: SHINE-OSS-L
               ${{ if eq(parameters.useVSPreview, true) }}:
-                demands: ImageOverride -equals SHINE-VS17-Preview
+                demands: ImageOverride -equals SHINE-VS18-Preview
+              ${{ else }}:
+                demands: ImageOverride -equals SHINE-VS18-Latest
             buildPlatforms:
               - ${{ platform }}
             buildConfigurations: [Release]

.pipelines/v2/templates/pipeline-ui-tests-full-build.yml

@@ -29,7 +29,9 @@ stages:
             ${{ else }}:
               name: SHINE-OSS-L
             ${{ if eq(parameters.useVSPreview, true) }}:
-              demands: ImageOverride -equals SHINE-VS17-Preview
+              demands: ImageOverride -equals SHINE-VS18-Preview
+            ${{ else }}:
+              demands: ImageOverride -equals SHINE-VS18-Latest
           buildPlatforms:
             - ${{ parameters.platform }}
           buildConfigurations: [Release]

.pipelines/v2/templates/steps-build-installer-vnext.yml

@@ -36,7 +36,7 @@ steps:
     displayName: Build Shared Support DLLs
     inputs:
       solution: "**/installer/PowerToysSetup.slnx"
-      vsVersion: 17.0
+      vsVersion: 18.0
       msbuildArgs: >-
         /t:PowerToysSetupCustomActionsVNext;SilentFilesInUseBAFunction
         /p:RunBuildEvents=true;RestorePackagesConfig=true;CIBuild=true
@@ -75,7 +75,7 @@ steps:
     displayName: 💻 Build VNext MSI
     inputs:
       solution: "**/installer/PowerToysSetup.slnx"
-      vsVersion: 17.0
+      vsVersion: 18.0
       msbuildArgs: >-
         -restore
         /t:PowerToysInstallerVNext
@@ -92,7 +92,7 @@ steps:
     displayName: 👤 Build VNext MSI
     inputs:
       solution: "**/installer/PowerToysSetup.slnx"
-      vsVersion: 17.0
+      vsVersion: 18.0
       msbuildArgs: >-
         /t:PowerToysInstallerVNext
         /p:RunBuildEvents=false;PerUser=true;BuildProjectReferences=false;CIBuild=true
@@ -143,7 +143,7 @@ steps:
     displayName: 💻 Build VNext Bootstrapper
     inputs:
       solution: "**/installer/PowerToysSetup.slnx"
-      vsVersion: 17.0
+      vsVersion: 18.0
       msbuildArgs: >-
         -restore
         /t:PowerToysBootstrapperVNext
@@ -160,7 +160,7 @@ steps:
     displayName: 👤 Build VNext Bootstrapper
     inputs:
       solution: "**/installer/PowerToysSetup.slnx"
-      vsVersion: 17.0
+      vsVersion: 18.0
       msbuildArgs: >-
         /t:PowerToysBootstrapperVNext
         /p:PerUser=true;BuildProjectReferences=false;CIBuild=true

.pipelines/verifyAndSetLatestVCToolsVersion.ps1

@@ -1,9 +1,16 @@
-$VSInstances = ([xml](& 'C:\Program Files (x86)\Microsoft Visual Studio\Installer\vswhere.exe' -latest -requires Microsoft.VisualStudio.Component.VC.Tools.x86.x64 -include packages -format xml))
+# Build common vswhere base arguments
+$vsWhereBaseArgs = @('-latest', '-requires', 'Microsoft.VisualStudio.Component.VC.Tools.x86.x64')
+if ($env:VCWhereExtraVersionTarget) {
+    # Add version target if specified (e.g., '-version [18.0,19.0)' for VS2026)
+    $vsWhereBaseArgs += $env:VCWhereExtraVersionTarget.Split(' ')
+}
+
+$VSInstances = ([xml](& 'C:\Program Files (x86)\Microsoft Visual Studio\Installer\vswhere.exe' @vsWhereBaseArgs -include packages -format xml))
 $VSPackages = $VSInstances.instances.instance.packages.package
 $LatestVCPackage = ($VSPackages | ? { $_.id -eq "Microsoft.VisualCpp.Tools.Core" })
 $LatestVCToolsVersion = $LatestVCPackage.version;
 
-$VSRoot = (& 'C:\Program Files (x86)\Microsoft Visual Studio\Installer\vswhere.exe' -latest -requires Microsoft.VisualStudio.Component.VC.Tools.x86.x64 -property 'resolvedInstallationPath')
+$VSRoot = (& 'C:\Program Files (x86)\Microsoft Visual Studio\Installer\vswhere.exe' @vsWhereBaseArgs -property 'resolvedInstallationPath')
 $VCToolsRoot = Join-Path $VSRoot "VC\Tools\MSVC"
 
 # We have observed a few instances where the VC tools package version actually
@@ -24,5 +31,12 @@ If ($Null -Eq (Get-Item $PackageVCToolPath -ErrorAction:Ignore)) {
 }
 
 Write-Output "Latest VCToolsVersion: $LatestVCToolsVersion"
-Write-Output "Updating VCToolsVersion environment variable for job"
-Write-Output "##vso[task.setvariable variable=VCToolsVersion]$LatestVCToolsVersion"
+
+# VS2026 (MSVC 14.50+) doesn't need explicit VCToolsVersion - let MSBuild auto-select
+$MajorMinorVersion = [Version]::Parse($LatestVCToolsVersion)
+If ($MajorMinorVersion.Major -eq 14 -and $MajorMinorVersion.Minor -ge 50) {
+    Write-Output "VS2026 detected (MSVC 14.50+). Skipping VCToolsVersion override to allow MSBuild auto-selection."
+} Else {
+    Write-Output "Updating VCToolsVersion environment variable for job"
+    Write-Output "##vso[task.setvariable variable=VCToolsVersion]$LatestVCToolsVersion"
+}