步步为营 SharePoint 开发学习笔记系列八、SharePoint EventHandler开发

概要

SharePoint的EventHandler主要有Web Level，List Level，List Item Level，Email几种。SharePoint的event handler主要是继承SPWebEventReceiver, SPEmailEventReceiver, SPListEventReceiver和SPItemEventReceiver类去实现其中相应的方法来完成我们的需求。

开发设计

注册事件.

/// <summary>
/// EventHandler
/// </summary>
class EventHandler
{
    private string _assemblyFullName = string.Empty;
    public string AssemblyFullName
    {
        get
        {
            return _assemblyFullName;
        }
    }
    private string _className = string.Empty;
    public string ClassName
    {
        get
        {
            return _className;
        }
    }
    private SPEventReceiverType _eventType;
    private SPEventReceiverType EventType
    {
        get
        {
            return _eventType;
        }
    }
    private string _data = string.Empty;
    public string Data
    {
        get
        {
            return _data;
        }
    }
    private bool _deleteExistingEvents = false;
    public bool DeleteExistingEvents
    {
        get
        {
            return _deleteExistingEvents;
        }
    }
 
    /// <summary>
    /// EventHandler
    /// </summary>
    /// <param name="handlerAssembly"></param>
    /// <param name="handlerClass"></param>
    /// <param name="eventType"></param>
    /// <param name="data"></param>
    /// <param name="deleteExisting"></param>
    public EventHandler(string handlerAssembly, string handlerClass, SPEventReceiverType eventType, string data, bool deleteExisting)
    {
        this._eventType = eventType;
        this._data = data;
        this._assemblyFullName = handlerAssembly;
        this._className = handlerClass;
        this._deleteExistingEvents = deleteExisting;
    }
    /// <summary>
    /// Registers the event handler on the list with the specified name in the specified web.
    /// The function will not throw errors, but will return a string with any error or success description (a log)
    /// </summary>
    /// <param name="web">The SPWeb object of the sharepoint web site containing the list to attach the event handler to</param>
    /// <param name="listName">The name of the list to attach the event to</param>        
    /// <returns>A log of the event assignment</returns>
    public string RegisterEvent(SPWeb web, SPList list)
    {
        StringBuilder sb = new StringBuilder(string.Empty);
        try
        {
            SPEventReceiverDefinition eventReceiver = list.EventReceivers.Add();
            eventReceiver.Name = list.Title + EventType;
            eventReceiver.Type = this.EventType;
            eventReceiver.Assembly = this.AssemblyFullName;
            eventReceiver.Class = this.ClassName;
            eventReceiver.Data = this.Data;
            eventReceiver.Update();
            list.Update();
        }
        catch (Exception ex1)
        {
            sb.AppendLine("Could not register the event on the list in this site:" + Environment.NewLine + ex1.Message);
        }
        return sb.ToString();
    }
 
}

事件处理程序：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
 
using Microsoft.SharePoint;
using System.IO;
 
namespace SharePointBlog
{
    public class TestEventHandle : SPItemEventReceiver
    {
        public override void ItemUpdated(SPItemEventProperties properties)
        {
            try
            {
                SaveLog();
 
            }
            catch (Exception ex)
            {
                properties.ErrorMessage = ex.Message;
                properties.Cancel = true;
            }
        }
 
        public void SaveLog()
        {
            string path = @"c:\Log.txt";
            string text = "删除Item" + ":" + DateTime.Now.ToString();
            StreamWriter writer = new StreamWriter(path);
            writer.Write(text);
            writer.Close();
        }
 
    }
}