wpf - Login view - Login button is not disabled initially based on CanLogin value, untill we click it for the first time. -

i started looking caliburn micro 2.0.0 , started simple login page implementation. page xaml looks this

  <stackpanel grid.column="1" grid.row="1">         <stackpanel orientation="horizontal"                     margin="2">             <textblock text="login name"                        width="100"/>             <textbox x:name="loginname"                       width="200" />         </stackpanel>         <stackpanel orientation="horizontal"                     margin="2">             <textblock text="password"                         width="100"/>             <textbox x:name="password"                       width="200" />         </stackpanel>         <button x:name="login"                  content="submit"                 width="100"                 margin="2"/>     </stackpanel> 

and view model class looks this

  public class loginviewmodel : propertychangedbase {     private string loginname;     public string loginname     {                 {             return loginname;         }         set         {             loginname = value;             notifyofpropertychange(() => loginname);             notifyofpropertychange(() => canlogin);         }     }      private string password;     public string password     {         { return password; }         set         {             password = value;             notifyofpropertychange(() => password);             notifyofpropertychange(() => canlogin);         }     }      public bool canlogin     {                 {             return !string.isnullorwhitespace(loginname) && !string.isnullorwhitespace(password);         }     }      public void login()     {      } } 

i not sure if there mistakes in this. until click login first time, login button enabled.

and interestingly when work calibur 1.5 works perfectly....

please me fix this.