c# - ASP.Net 4.5 Model Binding Sorting By Navigation Property -

all,

i have grid view has following columns. paging work great, not sorting. everytime click on category column sort category error:

instance property 'category.categoryname' not defined type 'esa.data.models.entity.project'

this error statement not true because gridview able display column correctly.

here select method

    public iqueryable<project> getprojects()     {         applicationservices objservices = new applicationservices();         iqueryable<project> lstproject;         lstproject = objservices.getprojects();         return lstproject;     } 

any suggestion?

    <asp:gridview id="grdproject" runat="server" showheader="true"          autogeneratecolumns="false" cellpadding="2" cellspacing="2"          itemtype="esa.data.models.entity.project"         selectmethod="getprojects"         datakeynames="projectid"          allowsorting="true"         allowpaging="true"         pagesize="5">         <columns>             <asp:boundfield datafield="projectid" headertext="id " itemstyle-width="10" />             <asp:boundfield datafield="category.categoryname" headertext="category" sortexpression="category.categoryname" />             <asp:boundfield datafield="projectname" headertext="project name" itemstyle-width="300"  />             <asp:boundfield datafield="status.statusname" headertext="status" sortexpression="status.statusname"  />             <asp:boundfield datafield="addedbyuser.username" headertext="added by" itemstyle-width="120"  />             <asp:boundfield datafield="addeddate" headertext="added date" itemstyle-width="90" dataformatstring="{0:d}"  />         </columns>     </asp:gridview> 

i having similar issue listview control. solved this.

firstly i'm using code post marc gravell dynamic linq orderby on ienumerable<t>

in listview's 'onsorting' event added following code.

protected void lv_sorting(object sender, listviewsorteventargs e) {     e.cancel = true;     viewstate["orderby"] = e.sortexpression;     lvlist.databind(); } 

i added standard way capture sortdirection list

public sortdirection sortdirection {         {         if (viewstate["sortdirection"] == null)         {             viewstate["sortdirection"] = sortdirection.ascending;             return sortdirection.ascending;         }         else if ((sortdirection)viewstate["sortdirection"] == sortdirection.ascending)         {             viewstate["sortdirection"] = sortdirection.descending;             return sortdirection.descending;         }         else         {             viewstate["sortdirection"] = sortdirection.ascending;             return sortdirection.ascending;         }     }     set     {         viewstate["sortdirection"] = value;     } } 

in listview selectmethod looks (using extension method marc)

public iqueryable<someobject> getobjects([viewstate("orderby")]string orderby = null) {     var list = getsomeobjects();     if (orderby != null)     {         switch (sortdirection)         {             case sortdirection.ascending:                 list = list.orderbydescending(orderby);                 break;             case sortdirection.descending:                 list = list.orderby(orderby);                 break;             default:                 list = list.orderbydescending(orderby);                 break;         }     }     return list; } 

i haven't tried gridview i'm work same.

edit here example of linq extension class should work

public static class linqextensions {     public static iorderedqueryable<t> orderby<t>(this iqueryable<t> source, string property)     {         return applyorder<t>(source, property, "orderby");     }     public static iorderedqueryable<t> orderbydescending<t>(this iqueryable<t> source, string property)     {         return applyorder<t>(source, property, "orderbydescending");     }     public static iorderedqueryable<t> thenby<t>(this iorderedqueryable<t> source, string property)     {         return applyorder<t>(source, property, "thenby");     }     public static iorderedqueryable<t> thenbydescending<t>(this iorderedqueryable<t> source, string property)     {         return applyorder<t>(source, property, "thenbydescending");     }     static iorderedqueryable<t> applyorder<t>(iqueryable<t> source, string property, string methodname)     {         string[] props = property.split('.');         type type = typeof(t);         parameterexpression arg = expression.parameter(type, "x");         expression expr = arg;         foreach (string prop in props)         {             // use reflection (not componentmodel) mirror linq             propertyinfo pi = type.getproperty(prop);             expr = expression.property(expr, pi);             type = pi.propertytype;         }         type delegatetype = typeof(func<,>).makegenerictype(typeof(t), type);         lambdaexpression lambda = expression.lambda(delegatetype, expr, arg);          object result = typeof(queryable).getmethods().single(                 method => method.name == methodname                         && method.isgenericmethoddefinition                         && method.getgenericarguments().length == 2                         && method.getparameters().length == 2)                 .makegenericmethod(typeof(t), type)                 .invoke(null, new object[] { source, lambda });         return (iorderedqueryable<t>)result;     }  } 

simply add using 'whatevernamespaceyouused' page , should go.