I struggled a lot with the API and I found out that the read only property is also available via an another way<\/strong>.<\/p>\n

First of all, you have to add the UIAutomationClient.dll assembly as a reference.<\/p>\n

The solution is to get the native element linked to the WpfEdit which is of AutomationElement type. With it I can retrieve the the TextPattern which is supported by the RichTextBox automation peer. <\/p>\n

This pattern can be use to select the whole text in the RichTextbox. Then you can retrieve the selection with the same pattern and ask for the IsReadOnly attribute value<\/strong>.<\/p>\n

Pretty easy to find no ? (I am just kidding here :-s) !<\/p>\n

The resulting, commented, code is here :
\n[csharp]
\n public static bool IsReadOnly(this WpfEdit richText)
\n {
\n if (richText == null) throw new ArgumentNullException("richText");<\/p>\n

\/\/We are in WPF so NativeElement is of AutomationElement type.
\n var element = richText.NativeElement as AutomationElement;<\/p>\n

\/\/Retrieve the TextPattern,
\n var pattern = element.GetCurrentPattern(TextPattern.Pattern) as TextPattern;
\n if (pattern == null)
\n throw
\n new InvalidOperationException("Cannot retrieve the info from the control");<\/p>\n

\/\/use the pattern to select the whole RichTextBox
\n pattern.DocumentRange.Select();<\/p>\n

\/\/ use the pattern to get the selection
\n var selection = pattern.GetSelection();<\/p>\n

if (selection.Any())
\n {
\n \/\/Retrieve the value of the IsReadOnly attribute
\n var attValue = selection[0]
\n .GetAttributeValue(TextPattern.IsReadOnlyAttribute);
\n if (attValue == null)
\n throw
\n new InvalidOperationException("Cannot retrieve the info from the control");<\/p>\n

\/\/This is a boolean my dear
\n return bool.Parse(attValue.ToString());
\n }<\/p>\n

throw
\n new InvalidOperationException("Cannot retrieve the info from the control");
\n }
\n[\/csharp]<\/p>\n