MVC EF Framework, loading foreign Key object serialized object times wrong serialization of object with type XX detected circular reference

Newtonsoft.Json.dll or through-"tools-" library package management tool-"NuGet Management Pack-" online input newtonsoft or json.net

Newtonsoft.json is possible:

Context. Response.ContentType = "Text/plain";
Booksservice service = new Booksservice ();
List<books> List=service. GetAll (). Take (5). ToList ();
jsonserializersettings setting = new Jsonserializersettings ()
{
referenceloophandling = Referenceloophandling.ignore
};

Strintret = Jsonconvert.serializeobject (list, setting);
Context. Response.Write (ret);

Easyui Code

$ (' #BooKlist '). DataGrid ({
URL: ' Bookhandler.ashx?flag=getbooklist ',
Pagination:true,
PageList: [5, 15, 20, 25],
Pagesize:5,
Columns: [[
{field: ' title ', Title: ' title ', width:120},
{field: ' Author ', title: ' Author ', width:120},
{field: ' ISBN ', Title: ' ISBN ', width:120},
{
Field: ' Publishersid ', title: ' publisher ', width:120,
Formatter:function (value, row, index) {
Return row. Publishers.name;
}

},
{
Field: ' CategoryId ', title: ' Book category ', width:120,
formatter:function (value, row, index) {
Return row. Categories.name;
}
}

]]
});

MVC EF Framework, loading foreign Key object serialized object times wrong serialization of object with type XX detected circular reference