ExportDropDownFormFieldAsText

public bool ExportDropDownFormFieldAsText { get; set; }

Document doc = new Document();
DocumentBuilder builder = new DocumentBuilder(doc);

// Use a document builder to insert a combo box with the value "Two" selected.
builder.InsertComboBox("MyComboBox", new[] { "One", "Two", "Three" }, 1);

// The "ExportDropDownFormFieldAsText" flag of this SaveOptions object allows us to
// control how saving the document to HTML treats drop-down combo boxes.
// Setting it to "true" will convert each combo box into simple text
// that displays the combo box's currently selected value, effectively freezing it.
// Setting it to "false" will preserve the functionality of the combo box using <select> and <option> tags.
HtmlSaveOptions options = new HtmlSaveOptions();
options.ExportDropDownFormFieldAsText = exportDropDownFormFieldAsText;    

doc.Save(ArtifactsDir + "HtmlSaveOptions.DropDownFormField.html", options);

string outDocContents = File.ReadAllText(ArtifactsDir + "HtmlSaveOptions.DropDownFormField.html");

if (exportDropDownFormFieldAsText)
    Assert.True(outDocContents.Contains(
        "<span>Two</span>"));
else
    Assert.True(outDocContents.Contains(
        "<select name=\"MyComboBox\">" +
            "<option>One</option>" +
            "<option selected=\"selected\">Two</option>" +
            "<option>Three</option>" +
        "</select>"));