Get Selected Feature from ArcMap

This blog defines how to get selected feature from ArcMap.

        IMxDocument pMxDoc = m_application.Document as IMxDocument;

        IMap pMap = pMxDoc.FocusMap;
        IEnumFeature pEnumFeat = pMap.FeatureSelection as IEnumFeature;
        pEnumFeat.Reset();
        IFeature pFeat = pEnumFeat.Next();
        if (pFeat == null)
        {
            MessageBox.Show("No Feature Selected.", "Information", MessageBoxButtons.OK, MessageBoxIcon.Information);
            System.Runtime.InteropServices.Marshal.ReleaseComObject(pEnumFeat);
            return;
         }
        IFields pFields;
        //Retrieving alla Fields value
        IEnumFeatureSetup enumFeatSetup = (IEnumFeatureSetup)pEnumFeat;
        enumFeatSetup.AllFields = true;
        while (pFeat != null)
        {
            pFields = pFeat.Fields;
            int indx = pFields.FindField("ID");
            if (indx == -1)
            {
                MessageBox.Show("ID field not found in selected feature ", "Not Found", MessageBoxButtons.OK, MessageBoxIcon.Error);
                pFeat = pEnumFeat.Next();
                continue;
             }
             object valu = pFeat.get_Value(indx);
            if (valu != null)
            {
                //Do something
            }
             pFeat = pEnumFeat.Next();
        }
        //Release Com object 
        System.Runtime.InteropServices.Marshal.ReleaseComObject(pEnumFeat);  

    }