c# - How to read XML documentation comments using Roslyn

Question

I would like to be able to read XML documentation comments while parsing C# source code using Roslyn.

/// <summary>
/// Documentation...
/// </summary>

I tried setting the ParseDocumentationComments in the ParseOptions, but it doesn't seem to have an effect?

var parseOptions = ParseOptions.Default.WithParseDocumentationComments(true);
SyntaxTree unit = SyntaxTree.ParseFile(file, parseOptions);

Answer 1

You'll need to either:

1. Look at the LeadingTrivia of the syntax that contains the XML doc comments
2. Construct a Compilation, find the Symbol that has the XML doc comment and use the GetDocumentationComment() method on it.

A complete example:

using Roslyn.Compilers.CSharp;
using System;
using System.Linq;

class Program
{
    static void Main(string[] args)
    {
        var tree = SyntaxTree.ParseText(@"
/// <summary>This is an xml doc comment</summary>
class C
{
}");
        var classNode = (ClassDeclarationSyntax)tree.GetRoot().Members.First();
        var trivia = classNode.GetLeadingTrivia().Single(t => t.Kind == SyntaxKind.DocumentationCommentTrivia);
        var xml = trivia.GetStructure();
        Console.WriteLine(xml);

        var compilation = Compilation.Create("test", syntaxTrees: new[] { tree });
        var classSymbol = compilation.GlobalNamespace.GetTypeMembers("C").Single();
        var docComment = classSymbol.GetDocumentationComment();
        Console.WriteLine(docComment.SummaryTextOpt);
    }
}