c# - How to Bind ItemsSource with ObservableCollection in WPF -

in wpf application - add new item observablecollection via button click event handler. want show added item adds observablecollection via binding itemscontrol wrote code not working. can solve problem. here code is:

.xaml file

    <dxlc:scrollbox verticalalignment="top">         <itemscontrol x:name="lstitemsclassm" itemssource="{binding path=topp,   mode=twoway}">             <itemscontrol.itemtemplate>                 <datatemplate>                     <stackpanel orientation="vertical">                         <button content="{binding name}"  tag="{binding pkid}"/>                       </stackpanel>                 </datatemplate>             </itemscontrol.itemtemplate>         </itemscontrol>      </dxlc:scrollbox> 

.cs file

     public observablecollection<classmm> topp { get; set; }      int dv , startindex, lastindex;      public mainwindow()     {          initializecomponent();         topp = new observablecollection<classmm>();         startindex=dv=1;         topp.add(new classmm() {  pkid=dv, name = "test 1" });         dv=2;         topp.add(new classmm() { pkid = dv, name = "test 2" });         dv = 3;         topp.add(new classmm() { pkid = dv, name = "test 3" });          dv = 4;         topp.add(new classmm() { pkid = dv, name = "test 4" });          lastindex=dv = 5;         topp.add(new classmm() { pkid = dv, name = "test 5" });       }      private void button_click(object sender, routedeventargs e)     {         lastindex = dv = dv++;          topp.add(new classmm() { pkid = dv, name =  musavebutton.content.tostring() });         foreach (var jk in topp.tolist())         {             messagebox.show(jk.name);         }     }      public class classmm : inotifypropertychanged {     public string _name;     public int _pkid;       public int pkid     {         { return _pkid; }         set         {             if (value != _pkid)             {                 _pkid = value;                 notifypropertychanged();             }         }     }        public string name     {         { return _name; }         set         {             if (value != _name)             {                 _name = value;                 notifypropertychanged();             }         }     }        public event propertychangedeventhandler propertychanged;      protected void notifypropertychanged(string propertyname = "")     {         if (propertychanged != null)         {             propertychanged(this, new propertychangedeventargs(propertyname));         }      }    } 

}

keep xaml original , modify cs follows :

 public observablecollection<classmm> topp { get; set; }          private int dv, startindex, lastindex;          public mainwindow()         {              initializecomponent();             datacontext = this;             topp = new observablecollection<classmm>();             startindex = dv = 1;             topp.add(new classmm() {pkid = dv, name = "test 1"});             dv = 2;             topp.add(new classmm() {pkid = dv, name = "test 2"});             dv = 3;             topp.add(new classmm() {pkid = dv, name = "test 3"});              dv = 4;             topp.add(new classmm() {pkid = dv, name = "test 4"});              lastindex = dv = 5;             topp.add(new classmm() {pkid = dv, name = "test 5"});           }          private void button_click(object sender, routedeventargs e)         {             lastindex = dv = dv++;              topp.add(new classmm() { pkid = dv, name = musavebutton.content.tostring() });             foreach (var jk in topp.tolist())             {                 messagebox.show(jk.name);             }         }          public class classmm : inotifypropertychanged         {             public string _name;             public int _pkid;               public int pkid             {                 { return _pkid; }                 set                 {                     if (value != _pkid)                     {                         _pkid = value;                         notifypropertychanged("pkid");                     }                 }             }                public string name             {                 { return _name; }                 set                 {                     if (value != _name)                     {                         _name = value;                         notifypropertychanged("name");                     }                 }             }                public event propertychangedeventhandler propertychanged;              protected void notifypropertychanged(string propertyname)             {                 if (propertychanged != null)                 {                     propertychanged(this, new propertychangedeventargs(propertyname));                 }             }         }