failed to show attribute window when add new feature by selecting from another layer

[XiujuZhou]

I have two polygon layers and create new feature for one layer by selecting polygon  from another layer. the selected polygon is highlighted without problem. I have a FeatureDataForm which is ESRI in house control as attribute data entry for the new feature, and need to show it right after the polygon is highlighted for user input for the new feature. the problem is that the FeatureDataForm apprears as blank popup window without attribute texbox. I need help of expertise here. the piece code is:
         
FeatureLayer myFeatureLayer = MyMap.Layers["dpcpoly"] as FeatureLayer; MyFeatureDataForm.FeatureLayer = myFeatureLayer;
MyFeatureDataForm.GraphicSource = copyGraphic; //copyGraphic is selected polygon from another layer.
FeatureDataFormBorder.Visibility = Visibility.Visible;

[XiujuZhou]

Thank you for your great help! Jennifer. It works.


I was using this as my target layer:
http://sampleserver3.arcgisonline.com/ArcGIS/rest/services/HomelandSecurity/operations/FeatureServer...
Notice, that the FeatureDataForm uses the proper control depending on the field type and the same validation check applies.