Passing the return value of a method to an Action

问题:

I will like to pass the variable "totalCount" to my view and let this display in a label or text area when my view loads. Here is my code below. How can I achieve this in Mvc 3?

Here is my class

public class person
    {

        public int Id { get; set; }
        public string FirstName { get; set; }
        public string LastName { get; set; }
        public string Address { get; set; }

        public person(int myId, string myFirstname, string myLastname, string myAddress)
        {
            Id = myId;
            FirstName = myFirstname;
            LastName = myLastname;
            Address = myAddress;
        }       
    }

Here is my controller ....

namespace WriteObjectToDb.Controllers
{
    public class HomeController : Controller
    {
        public ActionResult Index()
        {
            int result;
            List<person> mn = new List<person>();
            mn.Add(new person(1,"john", "adebayo", "shobanjo close jericho"));
            mn.Add(new person(2, "david", "johnson", "ibada close"));
            mn.Add(new person(3, "bayo", "olomale", "oluyole estate ringroad"));
            result =  WriteToDb(mn);

            return View(mn);

        }

        public ActionResult About()
        {
            return View();
        }


        /// <summary>
        /// 
        /// </summary>
        /// <param name="mn"></param>
        /// <returns></returns>
        private int WriteToDb(List<person> mn)
        {
            int totalCount;
            string connect = string.Empty;
            using (TransactionScope scope = new TransactionScope())
            {
                string sqlIns = "insert into table(firstname,lastname,address) values(@firstname,@lastname,@address)";
                SqlConnection cn = new SqlConnection(connect);
                SqlCommand cmdIns = new SqlCommand(sqlIns,cn);

                for(int i=0;i<mn.Count;i++)
                {
                    cmdIns.Parameters.AddWithValue("@firstname",mn[i].FirstName);
                    cmdIns.Parameters.AddWithValue("@lastname",mn[i].LastName);
                    cmdIns.Parameters.AddWithValue("@address",mn[i].Address);
                    cmdIns.ExecuteNonQuery();
                    cmdIns.Parameters.Clear();
                }
                scope.Complete();
                totalCount = mn.Count();
                return totalCount;
            }

        }

    }
}

Here is my view.....

@model IEnumerable<WriteObjectToDb.Models.person>

@{
    ViewBag.Title = "Index";
}

<h2>Index</h2>

<p>
    @Html.ActionLink("Create New", "Create")
</p>
<table>
    <tr>
        <th>
            FirstName
        </th>
        <th>
            LastName
        </th>
        <th>
            Address
        </th>
        <th></th>
    </tr>

@foreach (var item in Model) {
    <tr>
        <td>
            @Html.DisplayFor(modelItem => item.FirstName)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.LastName)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Address)
        </td>
        <td>
            @Html.ActionLink("Edit", "Edit", new { id=item.Id }) |
            @Html.ActionLink("Details", "Details", new { id=item.Id }) |
            @Html.ActionLink("Delete", "Delete", new { id=item.Id })
        </td>
    </tr>
}

</table>

回答1:

You can create new viewmodel class and add new property to it:

View model:

public class PersonsViewModel {
    public List<person> Persons { get; set; }
    public Int32 TotalCount{ get; set; }
}

Action:

 public ActionResult Index()
    {
        int result;
        var model = new PersonsViewModel();
        List<person> mn = new List<person>();
        mn.Add(new person(1,"john", "adebayo", "shobanjo close jericho"));
        mn.Add(new person(2, "david", "johnson", "ibada close"));
        mn.Add(new person(3, "bayo", "olomale", "oluyole estate ringroad"));
        result =  WriteToDb(mn);
        model.Persons = mn;
        model.TotalCount = 42; // your variable

        return View(model);

    }

View:

@model PersonsViewModel

@{
    ViewBag.Title = "Index";
}

<h2>Total : @Model.TotalCount</h2>

<p>
    @Html.ActionLink("Create New", "Create")
</p>
<table>
    <tr>
        <th>
            FirstName
        </th>
        <th>
            LastName
        </th>
        <th>
            Address
        </th>
        <th></th>
    </tr>

@foreach (var item in Model.Persons) {
    <tr>
        <td>
            @Html.DisplayFor(modelItem => item.FirstName)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.LastName)
        </td>
        <td>
            @Html.DisplayFor(modelItem => item.Address)
        </td>
        <td>
            @Html.ActionLink("Edit", "Edit", new { id=item.Id }) |
            @Html.ActionLink("Details", "Details", new { id=item.Id }) |
            @Html.ActionLink("Delete", "Delete", new { id=item.Id })
        </td>
    </tr>
}
</table>

回答2:

Store it in the ViewBag:

totalCount = 10;
ViewBag.TotalCount = totalCount;

Then in your view:

<span>@ViewBag.TotalCount</span>

回答3:

if TotalCount is just the count of Person objects in your model you can just use Model.Count.

To fully answer your question in the general case: you need to create a ViewModel class that contains all the data that you want to pass to the view, in your case List People and int TotalCount. Pass that view model to the view and access it's properties inside the view:

class MyPageNameViewModel
{
    public int TotalCount { get; set; }

    public List<Person> People { get; set; }

}