c# - How to completely clear/set text of WinRT's RichEditBox? -

how 1 overwrite or clear text (and formatting) of winrt's richeditbox?

i'm asking because method settext of it's document property seems append new text.

thus "binding" below:

void vm_propertychanged(object sender, system.componentmodel.propertychangedeventargs e) {     if (e.propertyname == "content")         richeditbox.document.settext(windows.ui.text.textsetoptions.none, vm.content); }  private void contentchanged(object sender, routedeventargs e) {     richeditbox box = (richeditbox)sender;      string content;     box.document.gettext(windows.ui.text.textgetoptions.none, out content);      vm.content = content; } 

where vm_propertychanged listens changes in content string property of viewmodel , contentchanged handler textchanged event of richeditbox, create infinite loop appending "\r" vm.content , box's text itself. when replace textgetoptions.none textgetoptions.formatrtf viewmodel's content property gets more messy adding looks empty rtf paragraphs.

here's content property definition in viewmodel can ensure everything's ok it:

    /// <summary>     /// <see cref="content" /> property's name.     /// </summary>     public const string contentpropertyname = "content";      private string _content;      /// <summary>     /// sets , gets content property.     /// changes property's value raise propertychanged event.      /// </summary>     public string content     {                 {             return _content;         }          set         {             if (_content == value)             {                 return;             }              raisepropertychanging(contentpropertyname);             _content = value;             raisepropertychanged(contentpropertyname);         }     } 

edit:

some experiments:

        richeditbox.document.settext(windows.ui.text.textsetoptions.none, string.empty);         string content;         richeditbox.document.gettext(windows.ui.text.textgetoptions.none, out content);         //content became "\r"          richeditbox.document.settext(windows.ui.text.textsetoptions.none, content);         richeditbox.document.gettext(windows.ui.text.textgetoptions.none, out content);         //content became "\r\r" 

edit:

another experiment:

a simple workaround textgetoptions.none trimming "\r" on output. textgetoptions.formatrtf things aren't simple:

        richeditbox box = new richeditbox();          box.document.settext(windows.ui.text.textsetoptions.formatrtf, string.empty);         string content;         box.document.gettext(windows.ui.text.textgetoptions.formatrtf, out content);          //content         // {\\rtf1\\fbidis\\ansi\\ansicpg1250\\deff0\\nouicompat\\deflang1045{\\fonttbl{\\f0\\fnil segoe ui;}}\r\n{\\colortbl ;\\red255\\green255\\blue255;}\r\n{\\*\\generator riched20 6.2.9200}\\viewkind4\\uc1 \r\n\\pard\\ltrpar\\tx720\\cf1\\f0\\fs17\\lang1033\\par\r\n}\r\n\0          box.document.settext(windows.ui.text.textsetoptions.formatrtf, content);         box.document.gettext(windows.ui.text.textgetoptions.formatrtf, out content);          //and it's         // {\\rtf1\\fbidis\\ansi\\ansicpg1250\\deff0\\nouicompat\\deflang1045{\\fonttbl{\\f0\\fnil segoe ui;}{\\f1\\fnil segoe ui;}}\r\n{\\colortbl ;\\red255\\green255\\blue255;}\r\n{\\*\\generator riched20 6.2.9200}\\viewkind4\\uc1 \r\n\\pard\\ltrpar\\tx720\\cf1\\f0\\fs17\\lang1033\\par\r\n\r\n\\pard\\ltrpar\\tx720\\f1\\fs17\\par\r\n}\r\n\0 

i apologize english. corrections concerning welcome :)

the /r (or \par if query rtf) appears bug in richeditbox. can worked around however, doing this:

        string temp;         // not ask rtf here, want raw text         richeditbox.document.gettext(textgetoptions.none, out temp);         var range = richeditbox.document.getrange(0, temp.length - 1);          string content;         // ask rtf here, if desired.         range.gettext(textgetoptions.formatrtf, out content);