c# - Bind two pages in wpf -

i need populate combobox in page1 address details of selected name contained in combobox held in mainwindow page. have tried code below, combobox name in mainwindow not recognised.

mainwindow:

private void displayparts()     {         try         {             sc.open();             string query = "select * parts";             sqlcommand createcommand = new sqlcommand(query, sc);             sqldatareader dr = createcommand.executereader();             while (dr.read())             {                 string name = dr.getstring(1);                  cbparts.items.add(name);//displaying list in combo box             }             sc.close();         }         catch (exception ex)         {             messagebox.show(ex.message);         }     } 

page1:

 private void combobox_selectionchanged_1(object sender, selectionchangedeventargs e)      {                    string constring = "data source=.;initial catalog=**.mdf;integrated security=true";        datacontext=mainwindow.          string query = "select * partners name='" + cbparts.selecteditem.tostring() + "' ;";          sqlconnection condatabase = new sqlconnection(constring);          sqlcommand cmddatabase = new sqlcommand(query, condatabase);          sqldatareader myreader;           try          {                sc.open();              myreader = cmddatabase.executereader();              if (myreader.read())              {                  txtpartner.text = myreader["name"].tostring();              }               myreader.close();                sc.close();          }          catch (exception ex)          {              messagebox.show(ex.message);          }      } 

// may need cast mainwindow's type var mainwindow = application.current.mainwindow;   //...  mainwindow.cbparts.items.add(name); 

additionally, bind combobox observablecollection property, , add items collection.