创建具有非数据库属性的PagedList

Question

使用以下模型:

public class Person
{
    public int PersonId { get; set; }
    [Display(Name = "First Name")]
    public string FirstName { get; set; }
    [Display(Name = "Middle Name(s)")]
    public string MiddleNames { get; set; }
    public string Surname { get; set; }
    public string Name
    {
        get
        {
            List<string> name = new List<string>();
            name.Add(this.FirstName);
            name.Add(this.MiddleNames);
            name.Add(this.Surname);
            return String.Join(" ", name.Where(n => !String.IsNullOrEmpty(n)));
        }
    }
}

我想创建一个视图模型的PagedList如下:

public class PersonSearch
{
    public int PersonId { get; set; }
    public string Name { get; set; }
}

做这件事最有效的方法是什么?

我不能使用下面的，因为它给了我一个错误的名字，这是预期的

var model = db.person.OrderBy(p => p.Surname)
                    .ThenBy(p => p.FirstName)
                    .Select(p => new PersonSearch
                    {
                        PersonId = p.PersonId,
                        Name = p.Name
                    })
                    .ToPagedList(page, 25);

在LINQ to Entities中不支持指定的类型成员'Name'

下面的操作可以工作，但是它首先会覆盖整个列表中的人:

var model = db.person.OrderBy(p => p.Surname)
                    .ThenBy(p => p.FirstName)
                    .ToList()
                    .Select(p => new PersonSearch
                    {
                        PersonId = p.PersonId,
                        Name = p.Name
                    })
                    .ToPagedList(page, 25);

下面的代码不起作用，因为它删除了分页信息:

var model = db.person.OrderBy(p => p.Surname)
                    .ThenBy(p => p.FirstName)
                    .ToPagedList(page, 25);
                    .Select(p => new PersonSearch
                    {
                        PersonId = p.PersonId,
                        Name = p.Name
                    })
                    .ToPagedList(page, 25);

Answer 1

添加一个构造函数到您的PersonSearch模型，以便您可以生成全名

public class PersonSearch
{
  public PersonSearch()
  {
  }
  public PersonSearch(string first, string middle, string last)
  {
    // format and remove leading or trailing white space as a result of nulls
    string name = string.Format("{0} {1} {2}", first, middle, last).Trim();
    // remove any internal extra white space if middle is null
    if (string.IsNullOrWhiteSpace(middle))
    {
      name = String.Join(" ", name.Split(new char[] { ' ' }, StringSplitOptions.RemoveEmptyEntries));
    }
    Name = name;
  }
  public int PersonId { get; set; }
  public string Name { get; set; }
}

然后在查询中使用

var model = db.person.OrderBy(p => p.Surname).ThenBy(p => p.FirstName)
  .Select(p => new PersonSearch(p.FirstName, p.MiddleNames, p.Surname)
  {
    PersonId = p.PersonId
  }).ToPagedList(page, 25);