Convert anonymous type to array or arraylist. Can it be done
Trying to retrieve data using linq from a database. I would like to use anonymous types and convert to an Ilist, Array, ArrayList or Collection. The data is used in a third party object that accepts Ilist, arraylist or collections.
I can't seem to get this to work. I get the following error, "Sequence operators not supported for type 'System.String'"
using (var db = new dbDataContext())
{
var query = from e in db.people
开发者_JAVA技巧 select new
{
Count = e.LastName.Count()
};
Array test;
test = query.ToArray();
}
It's got nothing to do with converting the results to array lists, or even anonymous types. Here's another version of your code which will fail:
using (var db = new dbDataContext())
{
var query = db.people.Select(x => x.LastName.Count());
foreach (int x in query)
{
Console.WriteLine(x);
}
}
That will still fail in the same way - because it's the translation of this bit:
x => x.LastName.Count()
into SQL which is causing problems.
Change it to:
x => x.LastName.Length
and I suspect you'll find it works. Note that this isn't really a C# issue - it's just LINQ to SQL's translation abilities.
I would suggest that you don't use an anonymous type here though - it's pointless. Maybe this isn't your complete code, but in general if you find yourself creating an anonymous type with a single member, ask yourself if it's really doing you any good.
The ArrayList class has a constructor that accepts ICollection.
You should be able to feed it a List version of your LINQ result.
using (var db = new dbDataContext()) {
var query = from e in db.people
select new { Count = e.LastName.Count() };
ArrayList list = new ArrayList(query.ToList());
}
I don't have Visual Studio here (I'm on my Mac), but it might be of help. (ToArray should suffice as well)
You might need to replace your Count() by Length.
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