通过 ViewBag 传递模型对象

Question

我想知道是否可以通过 ViewBag 传递模型对象。我尝试了以下代码，但不知何故在我的视图中，它只是显示的模型的路径。

控制器：

public ActionResult Tempo()
{
    DateTime date1 = new DateTime(1990, 1, 1);
    Employee emp = new Employee(3, "fara", "hass", date1, 56.6m, 0);
    ViewBag.EmployeeId = emp.EmployeeID;
    ViewBag.Fname = emp.Fname;
    ViewBag.Employee = emp;
}

查看：

@{
    ViewBag.Title = "Tempo";
}

@model LayoutProject.Models.Employee

<h2>Tempo</h2>
<div>
    <h4>ViewBag</h4>
    <br />
    EmployeeID: @ViewBag.EmployeeId
    <br />
    Fname: @ViewBag.Fname
    <br />
    Employee : @ViewBag.Employee
</div>

正确显示了 Fname 和 EmployeeId，但未正确显示 Employee 本身。我是否在这里遗漏了什么，或者根本无法通过 ViewBag 传递模型？

Answer 1

最好创建一个视图模型来传递给视图：

public class TempoViewModel
{
    public int EmployeeId { get; set; }
    public string FirstName { get; set; }

    public string LastName { private get; set; }
    public DateTime EmployeeStartDate { private get; set; }
    //any other properties here that make up EmployeeInformation

    public string EmployeeInformation
    { 
        get
        {
            //Format your employee information in the way you intend for the view
            return string.Format("Employee: {0}, {1}, {2}", this.FirstName, this.LastName, this.EmployeeStartDate);
        }
    }
}

然后让控制器创建视图模型：

public ViewResult Tempo()
{
    employee = //logic to retrieve employee information

    //map model to viewmodel
    var viewModel = new TempoViewModel()
    {
        EmployeeId = employee.EmployeeID,
        FirstName = employee.Fname,
        LastName = employee.Lname, //or set whatever properties are required to display EmployeeInformation
        EmployeeStartDate = employee.StartDate,
    };

    return View(viewModel);
}

然后在视图中显示视图模型：

@model TempoViewModel

@{
    ViewBag.Title = "Tempo";
}

<h2>Tempo</h2>
<div>
    <h4>Tempo Employee Information</h4>
    <br />
    EmployeeID: @Model.EmployeeId @* Do you really want to display the employee id? *@
    <br />
    Fname: @Model.FirstName
    <br />
    Employee: @Model.EmployeeInformation
</div>

---

更新：

使用您当前的实现，当您在视图中调用@ViewBag.Employee 时，您想要实现的是将模型写为字符串表示形式。在当前实现中，要将模型转换为字符串，需要调用模型的 ToString() 方法。由于您（可能）没有覆盖 ToString() 方法，因此会调用继承的对象实现，它会写出完整的命名空间和类名（当您说路径时，我假设您的意思是）。

要更正您当前的解决方案，您可以将 ToString() 的实现添加到您的 Employee 类。例如：

public class Employee
{
    public Employee(int employeeId, string firstName, string lastName)
    {
        this.EmployeeId = employeeId;
        this.FName = firstName;
        this.LName = lastName;
        //etc
    }

    public int EmployeeId { get; set; }
    public string FName { get; set; }
    public string LName { get; set; }

    public override string ToString()
    {
        //Implement your required string representation of the object here
        return string.Format("EmployeeId: {0}, FName: {1}, LName: {2}", EmployeeId, FName, LName);
    }
}