GroupBy clause add an "Item" property when projects the query

[jotab123]

Hi Stef,

GroupBy is adding an "extra" property called "Item" when I create a grouped query and projects it with Select.

//elements is a List<Element> where Element is a simple Class with a public int PropertyKey property generated
// with 0 or 1 value in a routine. 

var dynamicResult = elements.AsQueryable().GroupBy("PropertyKey").Select("new (it.key as PropertyKey)");
var result = elements.GroupBy(e => e.PropertyKey).Select(e => new { PropertyKey = e.Key}).AsQueryable();

//I think this should be true, but it isn't. dynamicResult add System.Object Item [System.String] property.
dynamicResult.ElementType.GetProperties().Count() == result.ElementType.GetProperties().Count()

Linq.Dynamic.Core 1.0.6.13

[jotab123]

I was trying in previous versions and works fine in 1.0.6.9. Doesn't work from 1.0.6.10.

[StefH]

This change is indeed introduced when I added Add [] to DynamicClass functionality.

If you need all property names, use https://github.com/StefH/System.Linq.Dynamic.Core/blob/master/src/System.Linq.Dynamic.Core/DynamicClass.cs#L282

[jotab123]

Ok, thanks! but, what is Item property? If I try to get the value throws an exception.

[StefH]

I think that when you use the same rules for getting the valid properties like https://github.com/StefH/System.Linq.Dynamic.Core/blob/master/src/System.Linq.Dynamic.Core/DynamicClass.cs#L188, all will work fine.

Or do you have a specific scenario?

[jotab123]

Using the previous example, If I try to get the value of property throws a System.Reflection.TargetParameterCountException.

var property = dynamicResult.ElementType.GetProperty("Item");
var value = property.GetValue(dynamicResult.First());

[StefH]

The Item property is an indexer, so you can't use this as a normal property.

See Q+A here;
http://stackoverflow.com/questions/291359/c-sharp-reflection-indexed-properties