c# - Exception while setting DataContext -

i have created custom usercontrol exposes dependencyproperties headertitle , headertitleforeground

public partial class pageheadercontrol : usercontrol {     public string headertitle      {         { return (string)getvalue(headertitleproperty); }         set { setvalue(headertitleproperty, value); }     }      public static readonly dependencyproperty headertitleproperty = dependencyproperty.register("headertitle", typeof(string), typeof(pageheadercontrol), new propertymetadata(""));      public string headertitleforeground     {         { return (string)getvalue(headertitleforegroundproperty); }         set { setvalue(headertitleforegroundproperty, value); }     }      public static readonly dependencyproperty headertitleforegroundproperty = dependencyproperty.register("headertitleforeground", typeof(string), typeof(pageheadercontrol), new propertymetadata(""));      public pageheadercontrol()     {         initializecomponent();         (this.content frameworkelement).datacontext = this;     } } 

but while debugging app throws exception show below:

  system.exception occurred    _hresult=-2146233088    _message=error hresult e_fail has been returned call com component.    hresult=-2146233088    message=error hresult e_fail has been returned call com component.    source=system.windows    stacktrace:       @ ms.internal.xcpimports.checkhresult(uint32 hr)    innerexception:  

however custom control correctly drawn. so, how can resolve this? critical issue?

your class pageheadercontrol dependency props registered elevationpageheadercontrol owner..?