Question

I have a simple Repeater Bound to a List of Objects, the object containing a series of strings for rendering.

The object is the following:

class BestPractice
    {
        public string Title { get; set; }
        public string Author { get; set; }
        public string Body { get; set; }
    }

rendered using the following code to make sure the loop wasn’t causing problems:

List<BestPractice> BestPractices = new List<BestPractice>();
foreach (SPListItem item in items)
                {
                    BestPractice bp = new BestPractice();
                    bp.Author = "test";//(string)item["Author"];
                    bp.Body = "test";// (string)item["Body"];
                    bp.Title = "test";// (string)item["Title"];
                    BestPractices.Add(bp);
                }

                BPRepeater.DataSource = BestPractices;
                BPRepeater.DataBind();

I’ve stepped through the code to make sure the List contained an item, and that that item had populated strings before being databound. The Exception happens here in the .g.cs file:

[global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Never)]
        public void @__DataBind__control4(object sender, System.EventArgs e) {
            System.Web.UI.WebControls.RepeaterItem Container;
            System.Web.UI.DataBoundLiteralControl target;
            target = ((System.Web.UI.DataBoundLiteralControl)(sender));
            Container = ((System.Web.UI.WebControls.RepeaterItem)(target.BindingContainer));
            target.SetDataBoundString(0, System.Convert.ToString(DataBinder.Eval(Container.DataItem, "Author"), System.Globalization.CultureInfo.CurrentCulture));
        }

The following is the exception itself:

System.Reflection.TargetInvocationException was unhandled by user code
  Message=Property accessor 'Author' on object 'Carpool_Webparts.Offer_Details.BestPractice' threw the following exception:'Carpool_Webparts.Offer_Details.BestPractice.get_Author()'
  Source=System
  StackTrace:
       at System.ComponentModel.ReflectPropertyDescriptor.GetValue(Object component)
       at System.Web.UI.DataBinder.GetPropertyValue(Object container, String propName)
       at System.Web.UI.DataBinder.Eval(Object container, String[] expressionParts)
       at Carpool_Webparts.Offer_Details.Offer_Details.__DataBind__control4(Object sender, EventArgs e)
       at System.Web.UI.Control.OnDataBinding(EventArgs e)
       at System.Web.UI.Control.DataBind(Boolean raiseOnDataBinding)
       at System.Web.UI.Control.DataBindChildren()
  InnerException: System.MethodAccessException
       Message=Carpool_Webparts.Offer_Details.BestPractice.get_Author()
       Source=mscorlib
       StackTrace:
            at System.Reflection.MethodBase.PerformSecurityCheck(Object obj, RuntimeMethodHandle method, IntPtr parent, UInt32 invocationFlags)
            at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture, Boolean skipVisibilityChecks)
            at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
            at System.ComponentModel.ReflectPropertyDescriptor.GetValue(Object component)
       InnerException: System.Security.SecurityException
            Message=Request for the permission of type 'System.Security.Permissions.ReflectionPermission, mscorlib, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089' failed.
            Source=mscorlib
            StackTrace:
                 at System.Security.CodeAccessSecurityEngine.ThrowSecurityException(Assembly asm, PermissionSet granted, PermissionSet refused, RuntimeMethodHandle rmh, SecurityAction action, Object demand, IPermission permThatFailed)
                 at System.Security.CodeAccessSecurityEngine.CheckSetHelper(PermissionSet grants, PermissionSet refused, PermissionSet demands, RuntimeMethodHandle rmh, Object assemblyOrString, SecurityAction action, Boolean throwException)
                 at System.Security.PermissionSetTriple.CheckSetDemand(PermissionSet demandSet, PermissionSet& alteredDemandset, RuntimeMethodHandle rmh)
                 at System.Security.PermissionListSet.CheckSetDemand(PermissionSet pset, RuntimeMethodHandle rmh)
                 at System.Security.PermissionListSet.DemandFlagsOrGrantSet(Int32 flags, PermissionSet grantSet)
                 at System.Security.CodeAccessSecurityEngine.ReflectionTargetDemandHelper(Int32 permission, PermissionSet targetGrant, CompressedStack securityContext)
                 at System.Security.CodeAccessSecurityEngine.ReflectionTargetDemandHelper(Int32 permission, PermissionSet targetGrant)
            InnerException: 

I am totally lost 🙁

Answer 1

I am not 100% certain what the specific issue is, but based on the error message, I would suggest two possible changes:

1) Verify that the BestPractice class is public (you can ratchet the exposure level back down once you verify it is or isn’t working).

2) Change the auto-implemented properties to member-backed properties. The inner exception indicates there is a security exception on the get_Author accessor, which leads me to believe that the auto-implementation could have something to do with it.