RichTextBox: Duplicated default ListItem entry in the DropDownList content form on XAML import

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Last Updated: 22 Jul 2026 13:17 by ADMIN

Scheduled for Scheduled for Q3 2026 (August)

Martin Ivanov

Created on: 30 Apr 2026 20:01

Category: RichTextBox

Type: Bug Report

RichTextBox: Duplicated default ListItem entry in the DropDownList content form on XAML import

When a DropDownList SDT form is saved in a XAML document and then imported with the XamlFormatProvider, an extra ListItem entry is added in the items collection of the DropDownList. The extra entry is the default "Choose an item".

To work this around, iterate all ComboBoxProperties and manually remove duplicates of the "Choose an item" entry.

var dropDownLists = radRichTextBox.Document.EnumerateChildrenOfType<SdtRangeStart>()
     .Where(x => x.SdtProperties is ComboBoxProperties)
     .Select(x => x.SdtProperties).OfType<ComboBoxProperties>();
 var defaultItemString = LocalizationManager.GetString("Documents_ContentControlsGenerator_ListItem");
 foreach (var item in dropDownLists)
 {
     if (item.Items.Count > 0 && item.Items.Any(x => x.Value != defaultItemString) && item.Items.Any(x => x.Value == defaultItemString))
     {
         var occurrence = item.Items.FirstOrDefault(x => x.Value == defaultItemString);
         while (occurrence != null)
         {
             item.Items.Remove(occurrence);
             occurrence = item.Items.FirstOrDefault(x => x.Value == defaultItemString);
         }
     }
 }