MVC error - The model item passed into the diction

问题:

I can't figure out what's going on with this error:

The model item passed into the dictionary is of type 'System.Collections.Generic.List1[RepositoryExample.Employee]', but this dictionary requires a model item of type 'RepositoryExample.Models.IEmployeeManagerRepository'.`

I get the error when I go to the Index view. I added the Index View from the controller but there is no code in it. I'm using Linq to SQL.

@model RepositoryExample.Models.IEmployeeManagerRepository

@{
ViewBag.Title = "Index";
}

<h2>Index</h2>

This is my code:

EmployeeController.cs

    // GET: /Employee/
    public ActionResult Index()
    {
        return View(_repository.ListEmployees());
    }

LinqEmployeeManagerRepository.cs

public class LinqEmployeeManagerRepository: RepositoryExample.Models.IEmployeeManagerRepository
{
    private DeptDirectoryDataClassesDataContext _db = new DeptDirectoryDataClassesDataContext();

    public Employee GetEmployee(string UserName)
    {
        return (from e in _db.Employees where e.UserName == UserName select e).FirstOrDefault();
    }

    public IEnumerable<Employee> ListEmployees()
    {
        return _db.Employees.ToList();
    }

    public Employee CreateEmployee(Employee employeeToCreate)
    {
        _db.Employees.InsertOnSubmit(employeeToCreate);
        _db.SubmitChanges();
        return employeeToCreate; 
    }

    public Employee EditEmployee(Employee employeeToEdit)
    { 
        var OriginalEmployee = GetEmployee(employeeToEdit.UserName);
        _db.Employees.Attach(employeeToEdit, OriginalEmployee);
        _db.SubmitChanges();
        return employeeToEdit; 
    }

    public void DeleteEmployee(Employee employeeToDelete)
    {
        var OriginalEmployee = GetEmployee(employeeToDelete.UserName);
        _db.Employees.DeleteOnSubmit(OriginalEmployee);
        _db.SubmitChanges();     
    }
}

IEmployeeManagerRepository.cs

namespace RepositoryExample.Models
{
    public interface IEmployeeManagerRepository
    {
        Employee CreateEmployee(Employee employeeToCreate);
        void DeleteEmployee(Employee employeeToDelete);
        Employee EditEmployee(Employee employeeToUpdate);
        Employee GetEmployee(string UserName);
        IEnumerable<Employee> ListEmployees(); 
    }
}

Any ideas what I'm doing wrong? I'm trying to follow the example on Repository pattern in this tutorial: http://www.asp.net/mvc/tutorials/iteration-4-make-the-application-loosely-coupled-cs.

回答1:

In the top of your Index.cshtml view replace:

@model RepositoryExample.Models.IEmployeeManagerRepository

with:

@model IEnumerable<RepositoryExample.Employee>

The _repository.ListEmployees() method returns IEnumerable<Employee> and that's what you are passing to the view here:

return View(_repository.ListEmployees());

So that's the type you should be using in the @model directive in your view.