In SharePoint 2007, -ed events are executed only
asynchronously.
This causes some problems between the main thread the and sub thread. For instance, -ed event thread sometimes cannot get its own item's "afterproperties".
Using SharePoint 2010,
-ed events can be executed either synchronously or asynchronously.
The two Event Receivers are as follows:
- -ing events (ItemAdding, ListAdding, etc)
- -ed events (ItemAdded, ListAdded, etc)
- synchronously or asynchronously
You can write "Synchronous" in Elements.xml in SharePoint EventReciver Project in Visual Studio 2010.
<Synchronization>Synchronous</Synchronization>
Listed below are the steps for making a synchronous -ed event:
- Create project as Event Receiver.
- Choose 2 events (ItemAdding and ItemAdded).
- Write the code. I added the current thread name in ULS log in ItemAdding and ItemAdded method to see status of thread. It is also necessary to add Microsoft.SharePoint.Administration namespace.
using System;
using System.Security.Permissions;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Security;
using Microsoft.SharePoint.Utilities;
using Microsoft.SharePoint.Workflow;
using Microsoft.SharePoint.Administration;
namespace EventReceiverProject4.EventReceiver1
{
/// <summary>
/// List Item Events
/// </summary>
public class EventReceiver1 : SPItemEventReceiver
{
/// <summary>
/// An item is being added.
/// </summary>
public override void ItemAdding(SPItemEventProperties properties)
{
System.Threading.Thread.CurrentThread.Name = "Current Thread";
string theadName = System.Threading.Thread.CurrentThread.Name;
SPDiagnosticsService.Local.WriteTrace(0, new SPDiagnosticsCategory("ItemAdding", TraceSeverity.Unexpected, EventSeverity.Error), TraceSeverity.Unexpected, theadName, theadName);
base.ItemAdding(properties);
}
/// <summary>
/// An item was added.
/// </summary>
public override void ItemAdded(SPItemEventProperties properties)
{
string theadName = System.Threading.Thread.CurrentThread.Name;
SPDiagnosticsService.Local.WriteTrace(0, new SPDiagnosticsCategory("ItemAdded", TraceSeverity.Unexpected, EventSeverity.Error), TraceSeverity.Unexpected, theadName, theadName);
base.ItemAdded(properties);
}
}
}
The ItemAdding and ItemAdded thread names are different because ItemAdded is run asynchronously.
The results are shown here:
- ItemAdding's thread name : Current Thread
- ItemAdded's thread name : null
Next, I added <Synchronization>Synchronous</Synchronization> in Elements.xml.
<?xml version="1.0" encoding="utf-8"?>
<Elements xmlns="http://schemas.microsoft.com/sharepoint/">
<Receivers ListTemplateId="104">
<Receiver>
<Name>EventReceiver1ItemAdding</Name>
<Type>ItemAdding</Type>
<Assembly>$SharePoint.Project.AssemblyFullName$</Assembly>
<Class>EventReceiverProject4.EventReceiver1.EventReceiver1</Class>
<SequenceNumber>10000</SequenceNumber>
<Synchronization>Synchronous</Synchronization>
</Receiver>
<Receiver>
<Name>EventReceiver1ItemAdded</Name>
<Type>ItemAdded</Type>
<Assembly>$SharePoint.Project.AssemblyFullName$</Assembly>
<Class>EventReceiverProject4.EventReceiver1.EventReceiver1</Class>
<SequenceNumber>10000</SequenceNumber>
</Receiver>
</Receivers>
</Elements>
The Results are shown here:
- ItemAdding's thread name : Current Thread
- ItemAdded's thread name : Current Thread
These are interesting results !!
