如何执行 LINQ 查询和 select？

Question

I am running the following:

var abc = new adminModel();
string text = abc.AnswerType.SingleOrDefault(s => s.Value == "2");
string text0 = abc.AnswerType.Single(s => s.Value == "2").Text;
var text1 = (from a in abc.AnswerType 
  here a.Value == "2"
  select a.Text).SingleOrDefault();

Where AnswerType looks like this:

public class adminModel
{

    public IEnumerable<SelectListItem> AnswerType
    {
        get
        {
            return new[]
                {
                    new SelectListItem { Value = "1", Text = "1 answer" },
                    new SelectListItem { Value = "2", Text = "2 answers" },
                    new SelectListItem { Value = "3", Text = "3 answers" },
                    new SelectListItem { Value = "4", Text = "4 answers" },
                    new SelectListItem { Value = "5", Text = "5 answers" },
                    new SelectListItem { Value = "6", Text = "6 answers" },
                    new SelectListItem { Value = "7", Text = "7 answers" },
                };
        }
    }

}

But I am getting an error message saying that "Can't convert SelectListItem to string". Is there a way that I can just extract the Text from the SelectListItem?

Answer 1

In your code AnswerType.SingleOrDefault(s => s.Value == "2") will return SelectedListItem instance, not a string .

If you need to get text the query would be:

string text = AnswerType.Single(s => s.Value == "2").Text;

or

string text = AnswerType
    .Where(s => s.Value == "2")
    .Select(arg => arg.Text)
    .SingleOrDefault();

Answer 2

Try this:

string text = AnswerType
        .Where(s => s.Value == "2")
        .Select(s=> s.Text)
        .SingleOrDefault();