Slow view building - asp.net-mvc

Question

I am in the process of converting an old asp.net forms application to MVC. I have run into a snag where I am displaying results of a search.
I have an entity framework model of Classes, Class Details, Rosters and Class instructors.
I have a search page where I wish to display all of the class details by class selected.
View:
#using System.Diagnostics
#model IEnumerable<SafetyReports.Models.DataModel.ClassDetails>
<div>
<table>
<tr>
<th>
Class Date
</th>
<th>
Location
</th>
<th>
Region
</th>
<th>
# of Attendees
</th>
</tr>
#foreach (var c in Model)
{
Debug.WriteLine(c.ClassDetailID);
<tr>
<td>
#c.ClassDate
</td>
<td>
#c.Location
</td>
<td>
#c.Region
</td>
<td>
#c.ClassRosters.Count
</td>
<td>
<input type="button" value="Detail" onclick="alert(#c.ClassDetailID)"/>
</td>
</tr>
}
</table>
</div>
controller:
public PartialViewResult SelectCourse(string id)
{
var e = new Entities();
var i = e.ClassDetails.Where(x => x.ClassID.ToString() == id).ToList();
return PartialView("_ClassesDetail", i);
}
My problem is that it seem to take about 1 second per 2-3 classes. I have one class type that has 1300 records and it takes about 5-6 minutes to return the view. What am I doing wrong? In the asp.net forms application I have a gridview that returns the same amount of data in seconds if that long. It isnt using EF though, just a sqldatasource. Could this be lazy loading?

Answer 1

firstly, as seen before using a int instead of a string for 'id' will speed up your EF query.
Here's one way to speed up the view rendering (or at least make it cleaner):
In view replace all the #foreach loop by a simple :
//here Razor will automatically repeat you model displayTemplate for
//each element of your IEnumerable
#Html.DisplayForModel()
And then define a Display Template for your model
~/Views/Shared/DisplayTemplates/ClassDetails.cshtml
#model SafetyReports.Models.DataModel.ClassDetails
<tr>
<td>
#Model.ClassDate
</td>
<td>
#Model.Location
</td>
<td>
#Model.Region
</td>
<td>
#Model.ClassRosters.Count
</td>
<td>
<input type="button" value="Detail" onclick="alert(#Model.ClassDetailID)"/>
</td>
</tr>

Answer 2

I found my issue, I had related objects being lazy loaded, I fixed the issue with including those objects with:
var i = e.ClassDetails.Where(x => x.ClassID == id).Include(x=>x.ClassInstructors).Include(x=>x.ClassRosters).ToList();