c# - Wpf Richtextbox selection starting column and row number returns different values -

i initializing richtextbox,

void initrtbflowdocument()     {         style nospacestyle = new style(typeof(paragraph));         nospacestyle.setters.add(new setter(paragraph.marginproperty, new thickness(0)));         rtbtexteditor.resources.add(typeof(paragraph), nospacestyle);     } 

i want richtext box selection words row , column numbers. wrote code follows, first time returning correctly.

void rtbtexteditor_selectionchanged(object sender, routedeventargs e)     {         //get richtext box selected text         init.rtbselectiontext = rtbtexteditor.selection.text.trim();         init.selectiontext = rtbtexteditor.selection.text.trim();         init.isselect = true;         if (init.rtbselectiontext != string.empty)         {             textpointer tp = rtbtexteditor.selection.start.getpositionatoffset(-2, logicaldirection.forward);             if (tp != null)                 getstartingindex();         }          init.rtbcontent = new textrange(rtbtexteditor.document.contentstart, rtbtexteditor.document.contentend).text;     }  void getstartingindex()     {         textpointer tp1 = rtbtexteditor.selection.start.getlinestartposition(0);         textpointer tp2 = rtbtexteditor.selection.start;          int selectioncolumnindex = tp1.getoffsettoposition(tp2)-1;//column number          int somebignumber = int.maxvalue;         int linemoved;         rtbtexteditor.selection.start.getlinestartposition(-somebignumber, out linemoved); //line number         int selectionrowindex = -linemoved;          init.rtbtextpoint = new rtbtextpointer();         init.rtbtextpoint.row = selectionrowindex;         init.rtbtextpoint.column = selectioncolumnindex;      } 

after clearing , added new content, position returns wrong number,

 public void displaycontent(string content)     {         //clear rich text box         rtbtexteditor.document.blocks.clear();          rtbtexteditor.document.blocks.add(new paragraph(new run(content)));     } 

is rong in above code. please me in advance!

this because contents in rtb not contain text, contains these things called textpointercontext's. textpointer's take account. can check textpointer adjacent using:

textpointer.getpointercontext(logicaldirection); 

to next textpointer:

textpointer.getnextcontextposition(logicaldirection); 

some sample code used in recent project, makes sure pointer context of type text:

while (start.getpointercontext(logicaldirection.forward)                               != textpointercontext.text) {     start = start.getnextcontextposition(logicaldirection.forward);     if (start == null) return; } 

when clear rtb, you're removing of these pointer contexts. careful when using getpositionatoffset(). should give "pointer" in right direction. if need more me know.

good hunting!