System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown in angularjs

Question

I have spent couple of weeks for this issue. but still I can't resolve this issue.

i am calling a web API service by using http in angularjs

           $http({
               method: 'GET',
               url: rootUrl + '/api/Project/ProjectList',
               headers: {
                   'Content-Type': "application/json; charset=utf-8"
               }
           }).success(function (response) {
               $scope.ProjectList = response;
           }).error(function (response, errorCode) {
               if (errorCode == 444) {
               }
           })

I have put break point in server and client side coding.

When i call the service, the server side method hit quickly

My server side method (am Using MVC WEB API with entity framework)

    [ActionName("ProjectList")]
    [HttpGet]   
    public IList<Project> ProjectList(Project projectModel)
    {
        return objIProjectService.ListOfProject();
    }

I checked, the service return 8 records( 8 rows from database) with a break point in objIProjectService.ListOfProject(); this line.

everything is going good. But my (response) http.success and http.error call back functions are hitting very slow.

Please see below image for the performance while i calling the http methods

Finally the http error function hit after 5 or 10 mins with this below error message.

System.OutOfMemoryException: Exception of type 'System.OutOfMemoryException' was thrown

This is the problem. Please let me know how can i solve it?

Actually am did something for this issue.

• I have cleared the temp folder - not working
• I have restart the Visual studio and clean the solution, restart my system and repairing visual studio.- not working
• But if I have deleted some rows in database (am using sql server 2008 r2 ), then it's working.

For example, if my database table have below than 7 rows, then it's working fast without that error. But if my table have more than 8 rows, then it's working very slowly and threw the error?? Why?? re could you please share your solution if you stuck this issue.

Answer 1

I think the problem is that the serialiser is accessing all the related properties on your project Class, so rather than directly returning the Entity Framework Class, create a new class to represent the data that you wish to send through your api (research further into DTO classes for further information)

You can use the Select Linq method to get a list of your new dto class populated with the data from your EF call.

var projects = objIProjectService.ListOfProject();

return projects.Select(p => new ProjectDTO() {
   ID = p.Id
   //... other properties of DTO class
}).ToList();

even better, if you put this select method, into your EF query (i.e. context.projects.Select(/* select info here */).ToList(), you can make sure EF is only bringing back the fields that you need

when building an API always check the json/XML response, make sure the serialised data contains what you were expecting it to produce. with entity framework this response can end up huge as it navigates through all the related tables pulling out all the linked information and then attempting to serialise it.

as a personal preference I always prefer to return an IHttpActionResult it allows you to manage what is being sent back to the client especially when there are issues, the controller has a number of methods you can use to createthis i.e. OK(), BadRequest(), InternalServerError() ...