Question

I’m perhaps being a bit lazy asking this here, but I’m just getting started with LINQ and I have a function that I am sure can be turned into two LINQ queries (or one nested query) rather than a LINQ and a couple of foreach statements. Any LINQ gurus care to refactor this one for me as an example?

The function itself loops through a list of .csproj files and pulls out the paths of all the .cs files included in the project:

static IEnumerable<string> FindFiles(IEnumerable<string> projectPaths) {                 string xmlNamespace = '{http://schemas.microsoft.com/developer/msbuild/2003}';     foreach (string projectPath in projectPaths)     {         XDocument projectXml = XDocument.Load(projectPath);         string projectDir = Path.GetDirectoryName(projectPath);          var csharpFiles = from c in projectXml.Descendants(xmlNamespace + 'Compile')                               where c.Attribute('Include').Value.EndsWith('.cs')                               select Path.Combine(projectDir, c.Attribute('Include').Value);         foreach (string s in csharpFiles)         {             yield return s;         }     } } 

Answer 1

How about:

        const string xmlNamespace = '{http://schemas.microsoft.com/developer/msbuild/2003}';          return  from projectPath in projectPaths                 let xml = XDocument.Load(projectPath)                 let dir = Path.GetDirectoryName(projectPath)                 from c in xml.Descendants(xmlNamespace + 'Compile')                 where c.Attribute('Include').Value.EndsWith('.cs')                 select Path.Combine(dir, c.Attribute('Include').Value);