c# - 从 IQueryable<String> 到 String

Question

我有一个模型，如下所示:

[Table("WebsiteText")]
public class WebsiteTextModel
{
    [Key]
    [DatabaseGeneratedAttribute(DatabaseGeneratedOption.Identity)]
    public int ID { get; set; }

    public string WebsiteSection { get; set; }

    [DataType(DataType.MultilineText)]
    public string TextToDisplay { get; set; }
}

我有一个 DataContext 类，如下所示:

public class WebsiteTextContext : DbContext
{
    public WebsiteTextContext()
        : base("DefaultConnection")
    {

    }

    public DbSet<WebsiteTextModel> WebsiteText { get; set; }
}

我想使用 LINQ 获取主页的网站文本，并将其填充到 ViewBag 中，所以我正在尝试这样做:

public ActionResult Index()
{
    var context = new WebsiteTextContext();

    var result = from x in context.WebsiteText
                 where x.WebsiteSection == "Home Page"
                 select x.TextToDisplay;

    ViewBag.Message = result;

    return View();
}

但是 var 是 IQueryable，我不知道如何将它变成字符串。这不起作用:

string result = from x in context.WebsiteText
    where x.WebsiteSection == "Home Page"
    select x.TextToDisplay;

这行不通:

var result = from x in context.WebsiteText
    where x.WebsiteSection == "Home Page"
    select x.TextToDisplay.ToString; //It's still IQueryable<String>

这行不通:

var result = from x in context.WebsiteText
    where x.WebsiteSection == "Home Page"
    select x.TextToDisplay.ToArray; //It's now IQueryable<char[]>

我需要做什么？

Answer 1

string result = (from x in context.WebsiteText
where x.WebsiteSection == "Home Page"
select x.TextToDisplay).FirstOrDefault();

您还有 First 和 Single 以及 SingleOrDefault

全部查看并选择最适合您的版本。