OpenXML Add paragraph style (Heading1,Heading2, Head 3 Etc) to a word processing document

Question

Can anybody guide me how to add predefined styles on paragraph using open XML Word Processing? I have tried various solutions available on forums but nothing works for me. Here is what i want to accomplish:

// Create a document by supplying the filepath. 
WordprocessingDocument wordDocument = WordprocessingDocument.Create("E:/Test/Executive.Docx", WordprocessingDocumentType.Document);

// Add a main document part. 
MainDocumentPart mainPart = wordDocument.AddMainDocumentPart();

// Create the document structure and add some text.
mainPart.Document = new Document();
Body body = mainPart.Document.AppendChild(new Body());
Paragraph para = body.AppendChild(new Paragraph());
   
Run run = para.AppendChild(new Run());
run.AppendChild(new Text("Executive Summary"));
if (para.Elements<ParagraphProperties>().Count() == 0)
    para.PrependChild<ParagraphProperties>(new ParagraphProperties());

// Get the ParagraphProperties element of the paragraph.
ParagraphProperties pPr = para.Elements<ParagraphProperties>().First();

// Set the value of ParagraphStyleId to "Heading3".
pPr.ParagraphStyleId = new ParagraphStyleId() { Val = "Heading1" };

Answer 1

Your technique would totally work if you were editing an existing document. The problem is that a fresh document doesn't have a "Heading 1" predefined. You'd have to add it. So you have two choices:

1. Work with an existing template document

Create a template document (TemplatePath) to use as a base. In the code, copy it to the final destination (FinalPath) and add text/whatever to it, applying styles. Heading 1 will already be in the template.

if (File.Exists(FinalPath))
  File.Delete(FinalPath);
File.Copy(TemplatePath, FinalPath);
WordprocessingDocument wordDocument = WordprocessingDocument.Open(FinalPath, true);
Paragraph para = body.AppendChild(new Paragraph());
Run run = para.AppendChild(new Run());
run.AppendChild(new Text("Executive Summary"));
para.ParagraphProperties = new ParagraphProperties(new ParagraphStyleId() { Val="Heading1" });

2. Create your new document from scratch

If you do this, it will have no built-in styles. So create a style, call it "Heading 1" and apply it to your paragraph.

WordprocessingDocument wordDocument = WordprocessingDocument.Create(FinalPath, WordprocessingDocumentType.Document);
MainDocumentPart mainPart = wordDocument.AddMainDocumentPart();
mainPart.Document = new Document();
Body body = mainPart.Document.AppendChild(new Body());
Paragraph para = body.AppendChild(new Paragraph());
Run run = para.AppendChild(new Run());
run.AppendChild(new Text("Executive Summary"));
StyleDefinitionPart styleDefinitionsPart = wordDocument.AddStylesDefinitionPart();
Styles styles = styleDefinitionsPart.Styles;
Style style = new Style() {
  Type = StyleValues.Paragraph, 
  StyleId = styleid, 
  CustomStyle = true
};
StyleName styleName1 = new StyleName() { Val = "Heading1" };
style.Append(styleName1);
StyleRunProperties styleRunProperties1 = new StyleRunProperties();
styleRunProperties1.Append(new Bold);
styleRunProperties1.Append(new Italic());
styleRunProperties1.Append(new RunFonts() { Ascii = "Lucida Console" };);
styleRunProperties1.Append(new FontSize() { Val = "24" });  // Sizes are in half-points. Oy!
style.Append(styleRunProperties1);
styles.Append(style);
pPr.ParagraphStyleId = new ParagraphStyleId(){ Val = "Heading1" };
para.PrependChild<ParagraphProperties>(new ParagraphProperties());

<sarcasm>See? OpenXML is a piece of cake!</sarcasm> I swear, my eyes are rolling so hard I'm getting a headache.