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);

How are you trying to read the XML comments exactly? – user7116 Apr 02 '13 at 15:23 — user7116, Apr 02 '13 at 15:23

score 35 · Accepted Answer · answered Apr 02 '13 at 15:52

You'll need to either:

Look at the LeadingTrivia of the syntax that contains the XML doc comments
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);
    }
}

The OP gives an example of a multiline comment. I have the same issue. Any chance you could re-write your code to demonstrate how to read a multiline documentation comment (as per the original question)? — Quark Soup, Aug 24 '15 at 20:35
For the `Symbol` case, it should be identical. For the syntax case, you would just look at the `MultiLineDocumentationCommentTrivia` — Kevin Pilch, Aug 25 '15 at 20:06
I think `GetDocumentationComment` has since been replaced with `GetDocumentationCommentXml` — Jack Ukleja, May 12 '16 at 08:00

score 7 · Answer 2 · answered Jul 12 '17 at 14:29

Just to update Kevin Pilch answer above:

Add Microsoft.CodeAnalysis.CSharp via nuget

Code will be as follows:

using System;
using System.Linq;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.CSharp.Syntax;

class Program
{
    static void Main(string[] args)
    {
        var tree = CSharpSyntaxTree.ParseText(@"
/// <summary> This is an xml doc comment </summary>
class C
{
}");
        var root = (CompilationUnitSyntax) tree.GetRoot();
        var classNode = (ClassDeclarationSyntax) (root.Members.First());

        var trivias = classNode.GetLeadingTrivia();
        var xmlCommentTrivia = trivias.FirstOrDefault(t => t.Kind() == SyntaxKind.SingleLineDocumentationCommentTrivia);
        var xml = xmlCommentTrivia.GetStructure();
        Console.WriteLine(xml);

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

Adding "Microsoft.CodeAnalysis.CSharp" is very important. Otherwise t.Kind() method will not work ! — Utsav Chokshi, Dec 07 '17 at 05:59

score 2 · Answer 3 · answered Dec 06 '17 at 13:33

Update :

FirstOrDefault method is no longer available. So use enumerator instead.

Updated code :

using System;
using System.Linq;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.CSharp.Syntax;

class Program
{
    static void Main(string[] args)
    {
        var tree = CSharpSyntaxTree.ParseText(@"
/// <summary> This is an xml doc comment </summary>
class C
{
}");
        var root = (CompilationUnitSyntax) tree.GetRoot();
        var classNode = (ClassDeclarationSyntax) (root.Members.First());

        var trivias = classNode.GetLeadingTrivia();
        var enumerator = trivias.GetEnumerator();
        while (enumerator.MoveNext())
        {
           var trivia = enumerator.Current;
           if(trivia.Kind().Equals(SyntaxKind.SingleLineDocumentationCommentTrivia))
           {
               var xml = trivia.GetStructure();
               Console.WriteLine(xml);
           }
        }
    }
}

How to read XML documentation comments using Roslyn

3 Answers3

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