在字符串列表中选择一个字符串

Question

Here I have a list of string in sites1. I need to check the common items between sites1 and items1 and select the matching items from items1. Here is my code

 string query = "/sitecore/content/*";
 List<string> sites1 = Sitecore.Configuration.Settings.Sites.Select(x => x.StartItem.TrimStart('/')).ToList();
 List<Item> items1 = Sitecore.Context.Database.SelectItems(query).Where(x => x.DisplayName.Contains(sites1)).ToList();

Any suggestion?

Edit: Here i am getting the error while selecting two items

 var sites = Sitecore.Configuration.Settings.Sites.Select(f => new List<string>() { f.StartItem.TrimStart('/'), f.Language }).ToList();
 List<Item> items = Sitecore.Context.Database.SelectItems(query).Where(x => sites.Contains(x.DisplayName.ToLower())).ToList();

Answer 1

It should be the other way around: site1.Contains(x.DisplayName) . Also, compared to a list HashSet<string> is more efficient for multiple look-ups, which becomes noticable as the number of items increases.

var sites1 = new HashSet<string>(Sitecore.Configuration.Settings.Sites
        .Select(x => x.StartItem.TrimStart('/')));

var items1 = Sitecore.Context.Database.SelectItems(query)
        .Where(x => site1.Contains(x.DisplayName))
        .ToList();

EDIT:

I did not notice that SelectItems() returns IQueriable . In that case I would re-write the second statement using IEnamerable.Any<> extention method, which can be projected into server SQL query.

var items1 = Sitecore.Context.Database.SelectItems(query)
        .Where(x=>sites1.Any(it=>it == x.DisplayName))
        .ToList();

EDIT 2: Correcting the query from the edited question:

var sites1 = Sitecore.Configuration.Settings.Sites
        .Select(x => new {DisplayName = x.StartItem.TrimStart('/'), Language = x.Language});

var siteNames = new HashSet<string>(sites1.Select(x=> x.DisplayName.ToLower());

var items1 = Sitecore.Context.Database.SelectItems(query)
        .Where(x=>siteNames.Any(it=>it == x.DisplayName.ToLower()))
        .ToList();

Answer 2

List<Item> items1 = Sitecore.Context.Database.SelectItems(query).Where(x => sites1.Contains(x.DisplayName)).ToList();