Error when using IFeatureCursor to inquire feature

Question

As you can see the other attributes are doing well, but the shape of the feature throw an exception "Shape = "(pFeature).Shape" raises an exception of type "System.Runtime.InteropServices.COMException"". Why?

 a = axMapControl1.get_Layer(j) as ICompositeLayer;

 pfl = a.get_Layer(0) as IFeatureLayer;
 IFeatureClass pfeatureclass = pfl.FeatureClass;
 if (pfl != null)
 {
 IQueryFilter queryFilter = new QueryFilterClass
 {
  SubFields = "Id",
  WhereClause = "Id = " + pointid
 };

 pFeatureSelection = pfl as IFeatureSelection;
 pFeatureSelection.Clear();
 pFeatureSelection.SelectFeatures(queryFilter, esriSelectionResultEnum.esriSelectionResultNew, true);
 pSelectionSet = pFeatureSelection.SelectionSet;
 IFeatureCursor pFeatureCursor = pfl.Search(queryFilter, true);          
 IFeature pFeature;
 pFeature = pFeatureCursor.NextFeature();   

Answer 1

Your issue is that you are only retrieving the "Id" field with your query. The

feature.Shape 

attribute is simply a shortcut for

feature.Value[shape_field_index] 

and therefore still requires you to retrieve it with your query.

IQueryFilter queryFilter = new QueryFilterClass
 {
  SubFields = "Id", "Shape" //or whatever your shape field is called
  WhereClause = "Id = " + pointid
 };