attach Event Receivers to content types in sharepoint

using System;
using System.Collections;
using System.Linq;
using System.Runtime.InteropServices;
using System.Security.Permissions;
using Microsoft.SharePoint;
using Microsoft.SharePoint.Security;
using Microsoft.SharePoint.Administration;

namespace SuryaFeature
{
///

/// This class handles events raised during feature activation, deactivation, installation, uninstallation, and upgrade.
///

///
/// The GUID attached to this class may be used during packaging and should not be modified.
///

[Guid("65b846e7-1d25-4396-bdab-36db28bb9a3e")]
public class FeatureEventReceiver : SPFeatureReceiver
{
private string sAssemblyFullName = string.Empty;
private string sClassName = string.Empty;
private string sOperationMode = string.Empty;
private SPEventReceiverDefinitionCollection oEventRecvDefColl = null;
private string[] sArrContentTypeNames = { "Leave Calendar", "Event Calendar", "Editorial Calendar" };

// Uncomment the method below to handle the event raised after a feature has been activated.
public override void FeatureActivated(SPFeatureReceiverProperties properties)
{
sOperationMode = "Activate";
PerformOperation(properties);
}

// Uncomment the method below to handle the event raised before a feature is deactivated.
public override void FeatureDeactivating(SPFeatureReceiverProperties properties)
{
sOperationMode = "Deactivate";
PerformOperation(properties);
}

private void GetAssemblyParameters(SPFeaturePropertyCollection properties)
{
sClassName = properties["AssemblyQualifiedName"].Value;

sAssemblyFullName = properties["AssemblyFullName"].Value;
}

private void PerformOperation(SPFeatureReceiverProperties _oProperties)
{
try
{
using (SPWeb oWeb = _oProperties.Feature.Parent as SPWeb)
{
GetAssemblyParameters(_oProperties.Feature.Properties);
SPListCollection oIntranetListColl = oWeb.Lists;

for (int iCount = 0; iCount < oIntranetListColl.Count; iCount++) { if (CheckForContentType(oIntranetListColl[iCount])) { // call this procedure to delete any existing event handlers DeleteEventHandlerToContentType(oIntranetListColl[iCount]); if (sOperationMode == "Activate") { SPEventReceiverDefinition oEventRecvDef = null; foreach (string _sArrItem in sArrContentTypeNames) { AddEventHandlerToContentType(oIntranetListColl[iCount], oEventRecvDef, "ItemAdding" + _sArrItem.Replace(" ", ""), SPEventReceiverType.ItemAdding, 1000, SPEventReceiverSynchronization.Synchronous); AddEventHandlerToContentType(oIntranetListColl[iCount], oEventRecvDef, "ItemUpdating" + _sArrItem.Replace(" ", ""), SPEventReceiverType.ItemUpdating, 1001, SPEventReceiverSynchronization.Synchronous); AddEventHandlerToContentType(oIntranetListColl[iCount], oEventRecvDef, "ItemDeleting" + _sArrItem.Replace(" ", ""), SPEventReceiverType.ItemDeleting, 1002, SPEventReceiverSynchronization.Synchronous); } } } } } } catch (Exception eEX) { SPDiagnosticsService.Local.WriteTrace(0, new SPDiagnosticsCategory("TravelCalendarFeatureReceiver", TraceSeverity.Unexpected, EventSeverity.Error), TraceSeverity.Unexpected, eEX.Message, eEX.StackTrace); } } private bool CheckForContentType(SPList _oListToUpdate) { if (_oListToUpdate.ContentTypes.Count > 0)
{
foreach (SPContentType _oContentType in _oListToUpdate.ContentTypes)
{
if (sArrContentTypeNames.Contains(_oContentType.Name)) { return true; }
}
}
return false;
}

private void DeleteEventHandlerToContentType(SPList _oListToUpdate)
{
// get all event receviers as definition collection
oEventRecvDefColl = _oListToUpdate.EventReceivers;
SPEventReceiverDefinition oEventRecvToDelete;
// create an array to store event receivers chosen for deletion
ArrayList oArrEventRecvToDelete = new ArrayList();
for (int i = 0; i < oEventRecvDefColl.Count; i++) { oEventRecvToDelete = oEventRecvDefColl[i]; if (oEventRecvToDelete.Type == SPEventReceiverType.ItemAdding) { oEventRecvToDelete.Delete(); } if (oEventRecvToDelete.Type == SPEventReceiverType.ItemUpdating) { oEventRecvToDelete.Delete(); } if (oEventRecvToDelete.Type == SPEventReceiverType.ItemDeleting) { oEventRecvToDelete.Delete(); } } } private void AddEventHandlerToContentType(SPList _oListToUpdate, SPEventReceiverDefinition _oEventRecvDef, string _sEventRecvDefName, SPEventReceiverType _oEventRecvType, int _iEventRecvSeq, SPEventReceiverSynchronization _oEventRecvSyn) { _oEventRecvDef = _oListToUpdate.EventReceivers.Add(); _oEventRecvDef.Assembly = sAssemblyFullName; _oEventRecvDef.Class = sClassName.Substring(0, sClassName.IndexOf(',')); _oEventRecvDef.Name = _sEventRecvDefName; _oEventRecvDef.Type = _oEventRecvType; _oEventRecvDef.SequenceNumber = _iEventRecvSeq; _oEventRecvDef.Synchronization = _oEventRecvSyn; _oEventRecvDef.Update(); } // Uncomment the method below to handle the event raised after a feature has been installed. //public override void FeatureInstalled(SPFeatureReceiverProperties properties) //{ //} // Uncomment the method below to handle the event raised before a feature is uninstalled. //public override void FeatureUninstalling(SPFeatureReceiverProperties properties) //{ //} // Uncomment the method below to handle the event raised when a feature is upgrading. //public override void FeatureUpgrading(SPFeatureReceiverProperties properties, string upgradeActionName, System.Collections.Generic.IDictionary parameters)
//{
//}
}
}