How to add hyperlink that links to heading in word with openxml
<p>I'm trying to add a hyperlink that links to a heading inside the same word document.</p>

<p>This is my code so far:</p>

<ol>
<li><p>First I add the hyperlink</p>

<pre><code>Paragraph p = new Paragraph();
Hyperlink h = new Hyperlink(){ Anchor = new StringValue("_Link") };
Run r = new Run();
RunProperties rp = new RunProperties(){ Val = "Hyperlink" };
Text t = new Text("Click here");

r.Append(rp);
r.Append(t);
p.Append(r);
body.Append(p);
</code></pre></li>
<li><p>Then I add the Heading (with the necessary Bookmark)</p>

<pre><code>Paragraph p = new Paragraph();
Run r = new Run(new Text("My Heading"));
ParagraphProperties pp = new ParagraphProperties();
ParagraphStyleId psi = new ParagraphStyleId(){ Val = new StringValue("Heading1") };

p.Append(r);
p.Append(pp);
p.Append(psi);
p.Append(new BookmarkStart() { Name = new StringValue("_Link") };
p.Append(new BookmarkEnd());
body.Append(p);
</code></pre></li>
</ol>

<p>I don't see what I'm missing. I set the anchor in the hyperlink, that should link to the Heading with a Bookmark which holds the equal name. (Anchor from hyperlink == Name from Bookmark in Heading).</p>

<p>Or do I need to add a HyperLinkRelationship to MainDocumentPart.HyperlinkRelationship, like I've to do when I want to add a hyperlink with an URI to a website?</p>