vb.net - Why isn't this Linq query on Dictionary<TKey, TValue> working as DataSource -

i have following in vb:

dim sources = source in importsources select new _     {.type = source.key, .source = source.value.name}  dgridsourcefiles.datasource = sources 

when debug, sources shows in-memory query , has 2 records within. yet datagrid view not show records.

so why won't work? suggestions can either vb or c#...

update

when use:

dim sources = (from source in importsources select new _     {.type = source.key, .source = source.value.name}).tolist() 

...the datasource displayed.

your linq query lazily evaluated , implements ienumerable<t> interface (as far know), means results not established until enumerator calls movenext somewhere (as happens within foreach loop, example).

it seems datasource property not enumerate contents in way. it's expecting implementation of ilist (or 1 of few other interfaces—see below) can access items index. used internally control sorting, filtering, etc. in mind, it's setting datasource property check object's type see whether implements of supported interfaces. don't think datasource property designed deal type of object (a lazily evaluated query) @ all.

now, tolist call populates list<t> results of query; does implement ilist , can therefore used datasource.

my understanding reason datasource typed merely object expects any of following interfaces:

• ilist
• ilistsource (in case ilistsource.getlist method used datamember property provide data control)
• ibindinglist (which propagates changes in list control ui updates)
• ibindinglistview (like bindingsource)

this according msdn documentation.