How to filter List<T> with LINQ and Reflection

Posted by Ehsan Sajjad on Stack Overflow See other posts from Stack Overflow or by Ehsan Sajjad
Published on 2014-08-22T10:12:37Z Indexed on 2014/08/22 10:20 UTC
Read the original article Hit count: 138

Filed under:
|
|
|
|

i am getting properties via reflection and i was doing like this to iterate on the list.

private void HandleListProperty(object oldObject, object newObject, string difference, PropertyInfo prop)
{

   var oldList = prop.GetValue(oldObject, null) as IList;
   var newList = prop.GetValue(newObject, null) as IList;

   if (prop.PropertyType == typeof(List<DataModel.ScheduleDetail>))
   {
      List<DataModel.ScheduleDetail> ScheduleDetailsOld = oldList as List<DataModel.ScheduleDetail>;
      List<DataModel.ScheduleDetail> ScheduleDetailsNew = newList as List<DataModel.ScheduleDetail>;

      var groupOldSchedules = ScheduleDetailsOld
                             .GroupBy(x => x.HomeHelpID)
                             .SelectMany(s => s.DistinctBy(d => d.HomeHelpID)
                             .Select(h => new { h.HomeHelpID, h.HomeHelpName }));
   }
}

Now i am making it generic because there will be coming different types of Lists and i don't want to put if conditions this way i want to write generic code to handle any type of list.

I came up with this way:

private void HandleListProperty(object oldObject, object newObject, string difference, PropertyInfo prop)
{

   var oldList = prop.GetValue(oldObject, null) as IList;
   var newList = prop.GetValue(newObject, null) as IList;

   var ListType = prop.PropertyType; 
   var MyListInstance = Activator.CreateInstance(ListType);

   MyListInstance = oldList;            
}

i am able to get the items in MyListInstance but as the type will come at runtime i am not getting how to write linq query to filter them, any ideah how to do.

© Stack Overflow or respective owner

Related posts about c#

Related posts about LINQ