Update azure-pipelines.yml

azure-pipelines.yml

@@ -113,6 +113,16 @@ jobs:
           Write-Host ("##vso[task.setvariable variable=NugetPackageVersion;]$tagVersion")
         displayName: Set NuGet Version to Tag Number
         condition: startsWith(variables['Build.SourceBranch'], 'refs/tags/')
+      # if this is a PR build, then update the version number
+      - powershell: |
+          $prNumber = $env:System_PullRequest_PullRequestNumber
+          $commitId = "$($env:System_PullRequest_SourceCommitId)".Substring(0, 7)
+          $fullVersionString = "$(CurrentSemanticVersionBase)-build.$prNumber+$commitId"
+          Write-Host("GitHub PR = $prNumber, Commit = $commitId");
+          Write-Host ("##vso[task.setvariable variable=NugetPackageVersion;]$fullVersionString")
+          Write-Host "##vso[build.updatebuildnumber]$fullVersionString"
+        displayName: Set NuGet Version to PR Version
+        condition: and(succeeded(), eq(variables['build.reason'], 'PullRequest'))
       # restore, build and pack the packages
       - task: MSBuild@1
         displayName: Build Xamarin.CommunityToolkit.csproj