In this article I will explain with an example, how to render (return) Partial View as string from Controller in ASP.Net MVC Razor.
The Partial View will be populated from database using Entity Framework, converted to a HTML string and then returned as String from Controller to the jQuery AJAX function using ContentResult function in ASP.Net MVC Razor.
 
 
Database
This article makes use of the Microsoft’s Northwind Database. The download and install instructions are provided in the link below.
 
 
Configuring and connecting Entity Framework to database
Now I will explain the steps to configure and add Entity Framework and also how to connect it with the database.
You will need to add Entity Data Model to your project by right clicking the Solution Explorer and then click on Add and then New Item option of the Context Menu.
MVC Partial View String: Render (Return) Partial View as String from Controller in ASP.Net MVC
 
From the Add New Item window, select ADO.NET Entity Data Model and set it’s Name as NorthwindModel and then click Add.
MVC Partial View String: Render (Return) Partial View as String from Controller in ASP.Net MVC
 
Then the Entity Data Model Wizard will open up where you need to select EF Designer database option.
MVC Partial View String: Render (Return) Partial View as String from Controller in ASP.Net MVC
 
Now the wizard will ask you to connect and configure the Connection String to the database.
MVC Partial View String: Render (Return) Partial View as String from Controller in ASP.Net MVC
 
You will need to select the
1.     SQL Server Instance
2.     Database
And then click Test Connection to make sure all settings are correct.
MVC Partial View String: Render (Return) Partial View as String from Controller in ASP.Net MVC
 
Once the Connection String is generated, click Next button to move to the next step.
MVC Partial View String: Render (Return) Partial View as String from Controller in ASP.Net MVC
 
Next you will need to choose the Entity Framework version to be used for connection.
MVC Partial View String: Render (Return) Partial View as String from Controller in ASP.Net MVC
 
Now you will need to choose the Tables you need to connect and work with Entity Framework. Here Customers Table is selected.
MVC Partial View String: Render (Return) Partial View as String from Controller in ASP.Net MVC
 
The above was the last step and you should now have the Entity Data Model ready with the Customers Table of the Northwind Database.
MVC Partial View String: Render (Return) Partial View as String from Controller in ASP.Net MVC
 
 
Namespaces
You will need to import the following namespace.
using System.IO;
 
 
Controller
The Controller consists of two Action methods.
Action method for handling GET operation
Inside this Action method, the Top 10 Customer records are fetched from the Customers Table of the Northwind Database and returned to the View.
 
Action method for handling jQuery AJAX POST operation
This Action method handles the call made from the jQuery AJAX POST function from the View.
The value of the customerId parameter is used to fetch the Customer record using Entity Framework which is then used to populate the Details Partial View.
Then using the ConvertViewToString method, the Partial View is converted to an HTML string.
The ConvertViewToString method accepts the Partial View name and the Model object as parameter. The name of the View and the context of the Controller are used to find the Partial View and its ViewEngineResult object is created.
Using the ViewEngineResult object, the ViewContext object is determined. Now using the Render function of the ViewEngineResult class, the Partial View is rendered into a StringWriter class object.
Finally the StringWriter class object is converted to String which is then returned to the View.
public class HomeController : Controller
{
    // GET: Home
    public ActionResult Index()
    {
        NorthwindEntities entities = new NorthwindEntities();
        return View(from customer in entities.Customers.Take(10)
                    select customer);
    }
 
    [HttpPost]
    public ContentResult Details(string customerId)
    {
        NorthwindEntities entities = new NorthwindEntities();
        string viewContent = ConvertViewToString("Details", entities.Customers.Find(customerId));
        return Content(viewContent);
    }
 
    privatestring ConvertViewToString(string viewName, object model)
    {
        ViewData.Model = model;
        using (StringWriter writer = new StringWriter())
        {
            ViewEngineResult vResult = ViewEngines.Engines.FindPartialView(ControllerContext, viewName);
            ViewContext vContext = new ViewContext(this.ControllerContext, vResult.View, ViewData, new TempDataDictionary(), writer);
            vResult.View.Render(vContext, writer);
            return writer.ToString();
        }
    }
}
 
 
View
Now you will need to Right Click inside the Controller class and click on the Add View option in order to create a View for the Controller.
The Name of the View is set to Index, the Template option is set to Empty, the Model class is set to Customer Entity (the one we have generated using Entity Framework) and finally the Data context class is set to NorthwindEntities.
MVC Partial View String: Render (Return) Partial View as String from Controller in ASP.Net MVC
 
Inside the View, in the very first line the Customer Entity is declared as IEnumerable which specifies that it will be available as a Collection.
For displaying the records, an HTML Table is used. A loop will be executed over the Model which will generate the HTML Table rows with the Customer records.
The last column of the HTML Table consists of an HTML Anchor Link. The HTML Anchor Link has been assigned a jQuery Click event handler.
When the HTML Anchor Link is clicked, a jQuery AJAX Call is made to the Details Action method of the Controller and the Details Partial View is fetched as HTML which is finally displayed using jQuery Modal Dialog Popup window.
Note: For more details on how to use jQuery AJAX for calling Controller’s Action method in ASP.Net MVC, please refer my article ASP.Net MVC: jQuery AJAX and JSON Example.
 
@model IEnumerable<Partial_View_MVC.Customer>
 
@{
    Layout = null;
}
 
<!DOCTYPE html>
 
<html>
<head>
    <meta name="viewport" content="width=device-width"/>
    <title>Index</title>
</head>
<body>
    <h4>Customers</h4>
    <hr/>
    <table cellpadding="0" cellspacing="0" id="CustomerGrid">
        <tr>
            <th>CustomerID</th>
            <th>Contact Name</th>
            <th>City</th>
            <th>Country</th>
            <th></th>
        </tr>
        @foreach (Customer customer in Model)
        {
            <tr>
                <td>@customer.CustomerID</td>
                <td>@customer.ContactName</td>
                <td>@customer.City</td>
                <td>@customer.Country</td>
                <td><a class="details" href="javascript:;">View</a></td>
            </tr>
        }
    </table>
    <div id="dialog" style="display: none">
    </div>
    <script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.2/jquery.min.js"></script>
    <script src="https://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.9/jquery-ui.js" type="text/javascript"></script>
    <link href="https://ajax.aspnetcdn.com/ajax/jquery.ui/1.8.9/themes/blitzer/jquery-ui.css"
          rel="stylesheet" type="text/css"/>
    <script type="text/javascript">
        $(function () {
            $("#dialog").dialog({
                autoOpen: false,
                modal: true,
                title: "View Details"
            });
            $("#CustomerGrid .details").click(function () {
                var customerId = $(this).closest("tr").find("td").eq(0).html();
                $.ajax({
                    type: "POST",
                    url: "/Home/Details",
                    data: '{customerId: "' + customerId + '" }',
                    contentType: "application/json; charset=utf-8",
                    dataType: "html",
                    success: function (response) {
                        $('#dialog').html(response);
                        $('#dialog').dialog('open');
                    },
                    failure: function (response) {
                        alert(response.responseText);
                    },
                    error: function (response) {
                        alert(response.responseText);
                    }
                });
            });
        });
    </script>
</body>
</html>
 
MVC Partial View String: Render (Return) Partial View as String from Controller in ASP.Net MVC
 
 
Partial View
In order to add Partial View, you will need to Right Click inside the Controller class and click on the Add View option in order to create a View for the Controller.
The Name of the View is set to Details, the Template option is set to Empty, the Model class is set to Customer Entity (the one we have generated using Entity Framework), the Data context class is set to NorthwindEntities and finally the Create as a partial view option needs to be checked.
MVC Partial View String: Render (Return) Partial View as String from Controller in ASP.Net MVC
 
Inside the Partial View, in the very first line the Customer Entity is declared as Model for the Partial View. The details of the Customer is displayed using the Html.DisplayFor helper method.
@model Partial_View_MVC.Customer
 
<table cellpadding="0" cellspacing="0" border="0">
   <tr>
        <td valign="top"><b>@Html.DisplayNameFor(model => model.Address):</b></td>
        <td>
            @Html.DisplayFor(model => model.Address)
            <br/>
            @Html.DisplayFor(model => model.City),
            @Html.DisplayFor(model => model.PostalCode)
            <br/>
            @Html.DisplayFor(model => model.Country)
        </td>
    </tr>
</table>
 
 
Screenshot
MVC Partial View String: Render (Return) Partial View as String from Controller in ASP.Net MVC
 
 
Downloads