实体框架查询以使用键值对填充视图模型，键值对包含太多参数

Question

I have three model classes in my code-first model.

public class Project
{
    public Guid Id { get; set; }
    public guid ProjectTypeId{ get; set; }
    public string projectType{ get; set; }
    [Required]
    public DateTime CreationDate{ get; set; }
    //more properties here
    //...
    public bool Activated{ get; set; }
    public IList<ProjectDetail> ProjectDetails{ get; set; }
}

As you can see a project has many details.

public class ProjectDetail
{
    [Required]
    public Guid Id { get; set; }
    public Project Project{ get; set; }
    [Required]
    public Guid ProjectId{ get; set; }             
    public string DetailDescription{ get; set; }
    public IList<ProjectDetailsAnswer> ProjectDetailsAnswers{ get; set; }
}

And a projectDetail has many answers:

public class ProjectDetailsAnswer
{
    [Required]
    public Guid Id { get; set; }
    [Required]
    public Guid ProjectDetailId{ get; set; }
    public ProjectDetail ProjectDetail{ get; set; }       
    public string OtherField{ get; set; }
    [Required]
    [MaxLength(512)]
    public string AnswerDescription{ get; set; }
}

This is my viewmodel

public class ProjectViewModel
{
    public Guid Id { get; set; }
    public List<KeyValuePair<string, List<string>>> Details { get; set; }
}

I wanted to populate that viewmodel with a keyvaluepair

var data = _dbContext.Project
                    .Select(p => new ProjectViewModel
                                  {
                                      Id = p.Id,
                                      Details = p.ProjectDetails
                                                 .Select(pd => new KeyValuePair<string, List<string>>(pd.DetailDescription, pd.ProjectDetailsAnswers.Select(pda => pda.AnswerDescription).ToList())
                                                 .ToList()
                                  })
                    .ToList();

However I get this error

KeyValuePair does not contain a constructor that takes that many arguments.

What am I doing wrong?

Thanks

Answer 1

I had the same problem. Turns out there was a typo "bad escape sequence" a couple lines up in my code in a string. Totally unrelated to the KeyValuePair line.