Saving FlowDocument to SQL Server

Question

I need to save WPF FlowDocuments to SQL Server. What is the best format for doing that? String? Blob? Does it matter in a document less than 5K words or so?

Answer 1

FlowDocument is not serializable so SWeko's answer above will not work. You can use the methods below to get the FlowDocument to and from a Xaml string which can then be saved in the database using nvarchar(max).

    var stringReader = new StringReader(info);
    var xmlTextReader = new XmlTextReader(stringReader);
    return (FlowDocument)XamlReader.Load(xmlTextReader);

and

    var infoString = XamlWriter.Save(info);

Answer 2

You can serialize FlowDocument using the TextRange class. You can even use the RTF format. Saving:

FlowDocument docToSave; // Lets suppose this var is initialized.
var tr = new TextRange(docToSave.ContentStart,docToSave.ContentEnd);
var dst = new MemoryStream();
tr.Save(dst, DataFormats.Rtf);
dst.Close();

And loading:

FlowDocument docToLoad = new FlowDocument();
var tr = new TextRange(docToLoad.ContentStart,docToLoad.ContentEnd);
Stream src; // Lets suppose it is initialized.
tr.Load(src, DataFormats.Rtf);
src.Close();

See also https://www.wpf-tutorial.com/rich-text-controls/how-to-creating-a-rich-text-editor/

Answer 3

If you just want to store the FlowDocument objects in a database, without any processing, I would recommend using binary serialization, and storing the resulting byte array into a varbinary(max). This is fast and scales well.

However, if you already have the FlowDocuments as XML files, than it would be easier just to dump them into a nvarchar(max) field, with no (added) serialization/deserialization overhead. This scales trivially for values under 8k, and then performs kinda OK until you hit around the 10MB mark.