How to get property value of a project file using msbuild - visual-studio

Question

Using MSBuild I include a solution>
<ItemGroup>
<ProjectToBuild Include="$(SVNLocalPath)\$(SolutionName)"> </ProjectToBuild>
</ItemGroup>
I need to include all the *.csproj file from the solution with the condition of the proj file contain or define a property; for example if x.csproj contain a defined property "TestProjectType" would like to include the project into my itemGroup
something like this
<Target Name = "TestProperties">
<Message Text="TestProperties"/>
<ItemGroup>
<AllProj Include="$(SVNLocalPath)\*.csproj"/>
<AllTestProj Include="%(AllProj.Identity)" Condition="%(AllProj.ProjectTypeGuids)=={3AC096D0-A1C2-E12C-1390-A8335801FDAB};{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}"/>
</ItemGroup>
<Message Text="#(AllTestProj )"/>
</Target>
Thanks

Answer 1

You can achieve that through custom task.
A simple sample to check a property (test) in all projects exclude current project of current solution:
<UsingTask TaskName="GetPropertyTask" TaskFactory="CodeTaskFactory" AssemblyFile="$(MSBuildToolsPath)\Microsoft.Build.Tasks.v12.0.dll">
<ParameterGroup>
<ProjectFile ParameterType="System.String" Required="true" />
<BuildOutput ParameterType="System.String[]" Output="true" />
</ParameterGroup>
<Task>
<Reference Include="System.Xml"/>
<Reference Include="Microsoft.Build"/>
<Using Namespace="Microsoft.Build" />
<Using Namespace="Microsoft.Build.Evaluation" />
<Using Namespace="Microsoft.Build.Utilities" />
<Code Type="Fragment" Language="cs">
<![CDATA[
var properties = new Dictionary<string, string>
{
{ "Configuration", "$(Configuration)" },
{ "Platform", "$(Platform)" }
};
//Log.LogMessage(MessageImportance.High, "customLog");
// Log.LogMessage(MessageImportance.High, ProjectFile);
var collection = new ProjectCollection(properties);
var project = collection.LoadProject(ProjectFile);
ProjectProperty pp = project.Properties.Where(p => p.Name == "MyCustomProperty").FirstOrDefault();
string customValue = pp==null?"empty":pp.EvaluatedValue;
BuildOutput = new String[] { customValue };
]]></Code>
</Task>
</UsingTask>
<Target Name="AfterBuild">
<GetPropertyTask ProjectFile="%(ProjectToScan.FullPath)">
<Output ItemName="ProjectToScanOutput" TaskParameter="BuildOutput"/>
</GetPropertyTask>
<Message Text="ClassLibrary1" Importance="high" Condition="'%(ProjectToScanOutput.Identity)' == 'test'" />
</Target>
More information, please refer to this article.