Consider the following scenario:
| You create a user control that uses the Microsoft .NET
Framework 2.0. |
| The user control uses a Microsoft ASP.NET 2.0 code-behind
file. |
| The ASP.NET 2.0 code-behind file defines a data
type. |
| You try to deserialize data that is
associated with the data type. |
In this scenario, you may receive an error message in the Web
server's event log that resembles the following:
Event code: 3011
Event message: A deserialization error occurred inside of ObjectStateFormatter. A property was typed as Type but the Type instance could not be created for 'YourCustomType, App_Web_6wc_5ues, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null'.
Event time: 15/05/2006 11:34:59 PM
Event time (UTC): 15/05/2006 3:34:59 AM
Event ID: 7878cf1cb270476f90c4d7f6191ed0ba
Event sequence: 3
Event occurrence: 1
Event detail code: 0
Application information:
Application domain: /LM/W3SVC/1/Root-1-12345678901234567
Trust level: Full
Application Virtual Path: /
Application Path: c:\inetpub\wwwroot\
Machine name: SERVER
Process information:
Process ID: 2596
Process name: aspnet_wp.exe
Account name: SERVER\ASPNET
Exception information:
Exception type: FileNotFoundException
Exception message: Could not load file or assembly 'App_Web_6wc_5ues, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null' or one of its dependencies. The system cannot find the file specified.
Request information:
Request URL: http://localhost/default.aspx
Request path: /
User host address: 127.0.0.1
User:
Is authenticated: False
Authentication Type:
Thread account name: SERVER\ASPNET
Thread information:
Thread ID: 1
Thread account name: SERVER\ASPNET
Is impersonating: False
Stack trace:
at System.RuntimeTypeHandle._GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark, Boolean loadTypeFromPartialName)
at System.RuntimeTypeHandle.GetTypeByName(String name, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark)
at System.RuntimeType.PrivateGetType(String typeName, Boolean throwOnError, Boolean ignoreCase, Boolean reflectionOnly, StackCrawlMark& stackMark)
at System.Type.GetType(String typeName, Boolean throwOnError)
at System.Web.UI.ObjectStateFormatter.DeserializeType(SerializerBinaryReader reader)
This problem occurs if the following conditions are true:
| You marked public properties on the user control by using the [Personalizable] attribute. Alternatively, you implemented the IPersonalizable interface in the code-behind file to programmatically control
which properties on the user control may be serialized and saved as
personalization data. |
| The [Personalizable] attribute or the IPersonalizable interface references a data type that was defined in an ASP.NET
2.0 code-behind page or in a user control. |
| The deserialization process works as expected until the
user control or the page that contains the data type definition is recompiled by
ASP.NET 2.0. |
This problem occurs when the user control or the page that
contains the data type definition is recompiled by ASP.NET 2.0. Every time that
ASP.NET 2.0 recompiles a user control or a page, ASP.NET 2.0 creates a new
auto-generated assembly. The error message occurs when the type information
that is stored in the personalization data tries to make a reference to the old
auto-generated assembly.
To work around this problem, define the data types that are
used for personalizable properties in one of the following locations:
| In classes in the App_Code folder |
| In assemblies in the Bin folder |
| In GAC-deployed assemblies |
The following code sample illustrates this problem.
public partial class TestUserControl : System.Web.UI.UserControl
{
// Define a user data type.
public enum userEnumDataType
{
Oranges = 1,
Apples = 2,
Bananas = 3
};
// Define a class member that uses the data type, and then assign a default value to it.
private userEnumDataType myEnumDataType = userEnumDataType.Apples;
// Define a property that uses the [Personalizable] attribute.
[Personalizable]
public userEnumDataType EnumDataType
{
get { return myEnumDataType; }
set { myEnumDataType = value; }
}
protected void Page_Load(object sender, EventArgs e)
{
refreshData(sender, e);
}
void refreshData(object sender, EventArgs e)
{
Label1.Text = myEnumDataType.ToString();
}
}
Microsoft has confirmed that this is a bug in the Microsoft products that are
listed in the "Applies to" section.
