正确用法
object a = pFeature.get_Value(fidIndex);
long fidValue = Convert.ToInt64(a) ;
错误用法
object a = pFeature.get_Value(fidIndex);
long fidValue = (long)a;
object a = pFeature.get_Value(fidIndex);
long fidValue = Convert.ToInt64(a) ;
object a = pFeature.get_Value(fidIndex);
long fidValue = (long)a;