Question

好的，看起来有人应该碰到这个，但我找不到任何有用的东西。这是我的情景。

我有一个客户和技能模型。目标是让客户对所有技能中的每一项进行评分。

所以，在这里我将粘贴模型，viewModel，Controller和View。最后关键问题

MODEL

namespace ClientSkills.Models
{
public class Client
{
    public int ClientId { get; set; }
    public string Name { get; set; }

    public ICollection<ClientSkills> Skills { get; set; }

}

public class Skill
{
    public int SkillId { get; set; }
    public string Name { get; set; }

    public ICollection<ClientSkills> Clients { get; set; }
}

public class Rating
{
    public int RatingId { get; set; }
    public string Name { get; set; }

    public ICollection<ClientSkills> ClientSkills { get; set; }

}

public class ClientSkills
{
    [Key, Column(Order=0)]
    public int ClientId { get; set; }

    [Key, Column(Order = 1)]
    public int SkillId { get; set; }
    public int RatingId { get; set; }

    public Rating Rating { get; set; }
    public Skill Skill { get; set; }
    public Client Client { get; set; }
}

public partial class ApplicationDbContext : IdentityDbContext<ApplicationUser>
{
    public DbSet<Client> Client { get; set; }
    public DbSet<Skill> Skill { get; set; }
    public DbSet<Rating> Rating { get; set; }
    public DbSet<ClientSkills> ClientSkills { get; set; }

}

}

查看模型

namespace ClientSkills.Models
{
public class RateViewModel
{
    public RateViewModel()
    {
        this.Skills = new List<SkillViewModel>();
    }

    public RateViewModel(Client client)
    {
        this.ClientId = client.ClientId;
        this.Skills = new List<SkillViewModel>();
        if (client.Skills.Count == 0)
        {
            var context = new ApplicationDbContext();
            foreach (var skill in context.Skill)
            {
                var skillVM = new SkillViewModel(skill);
                skillVM.SelectedRatingid = context.Rating.First(r => r.Name == "No aplica").RatingId;
                Skills.Add(skillVM);
            }
        }
        else
        {
            foreach (var item in client.Skills)
            {
                var skillVM = new SkillViewModel(item);
                skillVM.SelectedRatingid = item.SkillId;
                this.Skills.Add(skillVM);
            }
        }
    }

    public int ClientId { get; set; }

    public List<SkillViewModel> Skills { get; set; }

}

public class SkillViewModel
{

    public SkillViewModel()
    {
        Ratings = new List<Rating>();
    }
    public SkillViewModel(Skill skill)
    {
        var context = new ApplicationDbContext();
        this.Ratings = context.Rating.ToList();
        this.SkillId = skill.SkillId;
        this.SkillName = skill.Name;
    }

    public SkillViewModel(ClientSkills item)
    {
        var context = new ApplicationDbContext();
        this.Ratings = context.Rating.ToList();
        this.SkillId = item.SkillId;
        this.SkillName = item.Skill.Name;
        this.SelectedRatingid = item.RatingId;
    }
    public List<Rating> Ratings { get; set; }
    public int SelectedRatingid { get; set; }
    public int SkillId { get; set; }
    public string SkillName { get; set; }

}
}

CONTROLLER

namespace ClientSkills.Controllers
{
public class RateController : Controller
{
    //
    // GET: /Rate/Create
    public ActionResult Create()
    {
        //first, we assume there is an already selected user
        var context = new ApplicationDbContext();

        var client = context
            .Client
            .Include(c => c.Skills)
            .First(c => c.Name.ToLower() == "ricker");
        var model = new RateViewModel(client);
        return View(model);
    }
}
}

查看

使用向导创建一个Create视图，删除它创建的无用字段并将代码放在下面

<table>
        <tr>
            <td>Skill</td>
            <td>Rate</td>
        </tr>
        @foreach (var item in Model.Skills)
        {
            <tr>
                <td>
                    @Html.DisplayFor(model => model.Skills.First(i => i.SkillName == item.SkillName).SkillName, new { @class = "control-label col-md-2" })
                </td>
                <td>
                    @Html.DropDownListFor(x => item.SelectedRatingid, new SelectList(item.Ratings, "RatingId", "Name"), "Seleccione el valor")
                </td>
            </tr>
        }
</table>

问题是在行RateViewModel(Client client)的{{1}}构造函数中，我为selectedRatingId属性设置了默认值。我需要确保所有客户都具备所有技能，即使他们忘记或绕过其中一个。

当加载视图时，我确定ratesid设置得很好，技能名称看起来不错，但是drop dpwn列表没有显示所选的默认值。

如何使视图将selectedRatingId属性绑定到下拉列表控件？

Answer 1

将所选值传递给SelectList：

@Html.DropDownListFor(x => item.SelectedRatingid, new SelectList(item.Ratings, "RatingId", "Name", item.SelectedRatingid), "Seleccione el valor")

据我所知（正确或错误地），如果最后一个参数与其中一个选项值匹配，则它是一个对象 - 选择它，否则选择选项中的第一个参数。

有关Selectlist重载的详细信息。

如何为多对多关系构建创建视图

1 个答案: