Question

I have this:

if (Folder == "Unprocessed")
{
    var FolderEmails = from emails in EmailManagerDAL.Context.Emails
                        join activities in EmailManagerDAL.Context.EmailActivities on emails.ID equals activities.EmailID
                        where activities.EmailID != null
                        select new { emails.ID, emails.MessageFrom,emails.MessageSubject, emails.MessageDeliveryTime };
}
else // Processed
{

}

I need to move the FolderEmails var above the “if” but am having numerous difficulties.

Of course setting it to null initially is illegal.

I’ve tried stuff like this that also does not work:

var FolderEmails = new { ID = new int(), MessageFrom = string.Empty, MessageSubject = string.Empty, MessageDeliverTime = new DateTime() };

Could really use some help on this.

Thanks!

Answer 1

I don’t think anonymous types are intended to be used like you’re wanting (the compiler creates the anonymous type based on the assignment result). Why don’t you just declare a Tuple type and use it.

Edit:

IEnumerable<Tuple<int, string, string, DateTime>> FolderEmails = 
    default( IEnumerable<Tuple<int,string,string,DateTime>> );

if (folder == "Unprocessed")
{
    FolderEmails = from emails in EmailManagerDAL.Context.Emails
                    join activities in EmailManagerDAL.Context.EmailActivities on emails.ID equals activities.EmailID
                    where activities.EmailID != null
                    select new Tuple<int, string, string, DateTime>
                    (
                        emails.ID,
                        emails.MessageFrom,
                        emails.MessageSubject,
                        emails.MessageDeliveryTime
                    );
}
else // Processed
{

}

You need to change the “select new { field = value }” because it’s no longer an anonymous type being created, it’s a locally declared explicit type of:

Tuple<int,string,string,DateTime>

which are immutable value types so you’ll have to call the constructor to create them ( select new Tuple( values ) ).