c# - BindingExpression path error property not found in derived class -

i confusing binding internal property of base class.

i having below classes , b , tried bind class "a" property (which internal) in xaml.

  public class {     internal int myproperty     {         { return (int)getvalue(mypropertyproperty); }         set { setvalue(mypropertyproperty, value); }     }      // using dependencyproperty backing store myproperty.  enables animation, styling, binding, etc...     internal static readonly dependencyproperty mypropertyproperty =         dependencyproperty.register("myproperty", typeof(int), typeof(a), new propertymetadata(0));   }  public class b : {  } 

question :

while creating instance class datacontext set class , can bind internal property of class in xaml scenario binding property works without issues

issue:

but same scenario have created instance of class b inherits class a, datacontext set class b , cannot bind internal property of class a(from base class) , error thrown bindingexpression path error property “myproperty “not found in class b.

why scenario not works have same base class ,please share ideas this.