SharePoint提供程序托管加载项 - 安装加载项时多次触发应用程序事件接收器。 [英] SharePoint Provider Hosted Add-in - App Event receiver triggered multiple times when Add-in is Installed.

问题描述

我创建了提供商托管的加载项，我想在添加时通过托管代码创建列表在安装中。所以我创建了应用程序事件接收器并在其中添加了列表创建代码。

但是当我安装了加载项时，事件接收器被触发了4次。不要不，为什么会发生这种情况。

请帮助。

解决方案

您好，

以下AppEventReceiver类代码供您参考。

< pre class ="prettyprint"> public class AppEventReceiver：IRemoteEventService
{
///< summary>
///处理安装或升级应用程序后或卸载应用程序时发生的应用程序事件。
///< / summary>
///< param name =" properties">保存有关应用事件的信息。< / param>
///< returns>保存从应用事件返回的信息。< / returns>
public SPRemoteEventResult ProcessEvent（SPRemoteEventProperties properties）
{
SPRemoteEventResult result = new SPRemoteEventResult（）;
String listTitle =" TestListDennis" ;;
Guid listID = Guid.Empty;

switch（properties.EventType）
{
case SPRemoteEventType.AppInstalled：

try
{
listID = CreateList（ listTitle，properties）;
//取消注释下一行以测试异常处理。
//抛出新的异常（"我的测试异常"）;
//也尝试将前一行放在CreateList调用之上。
}
catch（例外e）
{
//告诉SharePoint取消该事件。
result.ErrorMessage = e.Message;
result.Status = SPRemoteEventServiceStatus.CancelWithError;

//删除列表（如果已创建）。
DeleteList（listID，properties）;
}
休息;
case SPRemoteEventType.AppUpgraded：
break;
case SPRemoteEventType.AppUninstalling：

try
{
RecycleList（listTitle，properties）;
//取消注释下一行以测试异常处理。
//抛出新的异常（"我的测试异常"）;
//同时尝试将前一行放在RecycleList调用之上。
}
catch（例外e）
{
//告诉SharePoint取消该事件。
result.ErrorMessage = e.Message;
result.Status = SPRemoteEventServiceStatus.CancelWithError;

//恢复列表，如果它在回收站中。
RestoreList（listTitle，properties）;
}
休息;
}
返回结果;
}


///< summary>
///此方法是必需的占位符，但不会被应用事件使用。
///< / summary>
///< param name =" properties"> Unused。< / param>
public void ProcessOneWayEvent（SPRemoteEventProperties properties）
{
throw new NotImplementedException（）;
}


私人Guid CreateList（String listTitle，SPRemoteEventProperties属性）
{
Guid listID = Guid.Empty;

using（ClientContext clientContext = TokenHelper.CreateAppEventClientContext（properties，useAppWeb：false））
{
if（clientContext！= null）
{
/ / SharePoint可能会在超时后重试该事件。它
//可能已经在这个处理程序的最后一次尝试中创建了列表，所以
//检查是否已经有一个具有该名称的列表。
列出targetList = GetListByTitle（listTitle，clientContext）;

//如果没有，请创建它。
if（targetList == null）
{
ListCreationInformation listInfo = new ListCreationInformation（）;
listInfo.Title = listTitle;
listInfo.TemplateType =（int）ListTemplateType.GenericList;
listInfo.Url = listTitle;
targetList = clientContext.Web.Lists.Add（listInfo）;
clientContext.Load（targetList，l => l.Id）;
clientContext.ExecuteQuery（）;
listID = targetList.Id;
}
}
}
返回listID;
}

private void DeleteList（Guid listID，SPRemoteEventProperties属性）
{
using（ClientContext clientContext = TokenHelper.CreateAppEventClientContext（properties，useAppWeb：false））
{
if（clientContext！= null）
{
//检查"尝试"是否块代码足以在错误出现之前创建列表。
列出targetList = GetListByID（listID，clientContext）;

//如果是，请删除列表。
if（targetList！= null）
{
targetList.DeleteObject（）;
clientContext.ExecuteQuery（）;
}
}
}
}
private List GetListByTitle（String listTitle，ClientContext clientContext）
{
ListCollection allLists = clientContext.Web。名单;
IEnumerable< List> matchingLists = clientContext.LoadQuery（allLists.Where（list => list.Title == listTitle））;
clientContext.ExecuteQuery（）;
返回matchingLists.FirstOrDefault（）;
}
private List GetListByID（Guid listID，ClientContext clientContext）
{
ListCollection allLists = clientContext.Web.Lists;
IEnumerable< List> matchingLists = clientContext.LoadQuery（allLists.Where（list => list.Id == listID））;
clientContext.ExecuteQuery（）;
返回matchingLists.FirstOrDefault（）;
}

private void RecycleList（字符串标题，SPRemoteEventProperties属性）
{
using（ClientContext clientContext = TokenHelper.CreateAppEventClientContext（properties，useAppWeb：false））
{
if（clientContext！= null）
{
//检查用户是否尚未在SharePoint UI中回收该列表。
列出targetList = GetListByTitle（title，clientContext）;

//如果它仍然存在，请回收它。
if（targetList！= null）
{
targetList.Recycle（）;
clientContext.ExecuteQuery（）;
}
}
}
}

private void RestoreList（字符串标题，SPRemoteEventProperties属性）
{
using（ClientContext clientContext = TokenHelper.CreateAppEventClientContext（properties，useAppWeb：false））
{
if（clientContext！= null）
{
//检查用户是否未手动从回收站中删除了列表
RecycleBinItemCollection bin = clientContext.Web.RecycleBin;
IEnumerable< RecycleBinItem> matchingItems = clientContext.LoadQuery（bin.Where（item => item.Title == title））;
clientContext.ExecuteQuery（）;
RecycleBinItem recycledList = matchingItems.FirstOrDefault（）;

//如果有，请恢复它。
if（recycledList！= null）
{
recycledList.Restore（）;
clientContext.ExecuteQuery（）;
}
}
}
}
}

完整示例代码：
https://github.com/SharePoint/PnP/tree/master/Samples/Core.AppEvents

最好的问候，

Dennis

Hi,

I have created provider hosted add-in and I want to create list through managed code when add-in gets installed. So i have created app event receiver and added list creation code in it.

But when i installed add-in, event receiver gets triggered 4 times. Don't no why this is happened.

Kindly Help.

解决方案

Hi,

The following AppEventReceiver class code for your reference.

public class AppEventReceiver : IRemoteEventService
{
	/// <summary>
	/// Handles app events that occur after the app is installed or upgraded, or when app is being uninstalled.
	/// </summary>
	/// <param name="properties">Holds information about the app event.</param>
	/// <returns>Holds information returned from the app event.</returns>
	public SPRemoteEventResult ProcessEvent(SPRemoteEventProperties properties)
	{
		SPRemoteEventResult result = new SPRemoteEventResult();
		String listTitle = "TestListDennis";
		Guid listID = Guid.Empty;

		switch (properties.EventType)
		{
			case SPRemoteEventType.AppInstalled:

				try
				{
					listID = CreateList(listTitle, properties);
					// Uncomment the next line to test exception handling.
					// throw new Exception("My test exception");
					// Also try putting the preceding line above the CreateList call.
				}
				catch (Exception e)
				{
					// Tell SharePoint to cancel the event.
					result.ErrorMessage = e.Message;
					result.Status = SPRemoteEventServiceStatus.CancelWithError;

					// Delete the list if it was created.
					DeleteList(listID, properties);
				}
				break;
			case SPRemoteEventType.AppUpgraded:
				break;
			case SPRemoteEventType.AppUninstalling:

				try
				{
					RecycleList(listTitle, properties);
					// Uncomment the next line to test exception handling.
					// throw new Exception("My test exception");
					// Also try putting the preceding line above the RecycleList call.
				}
				catch (Exception e)
				{
					// Tell SharePoint to cancel the event.
					result.ErrorMessage = e.Message;
					result.Status = SPRemoteEventServiceStatus.CancelWithError;

					// Recover the list if it is in Recycle Bin.
					RestoreList(listTitle, properties);
				}
				break;
		}
		return result;
	}


	/// <summary>
	/// This method is a required placeholder, but is not used by app events.
	/// </summary>
	/// <param name="properties">Unused.</param>
	public void ProcessOneWayEvent(SPRemoteEventProperties properties)
	{
		throw new NotImplementedException();
	}


	private Guid CreateList(String listTitle, SPRemoteEventProperties properties)
	{
		Guid listID = Guid.Empty;

		using (ClientContext clientContext = TokenHelper.CreateAppEventClientContext(properties, useAppWeb: false))
		{
			if (clientContext != null)
			{
				// SharePoint might be retrying the event after a time-out. It
				// may have created the list on the last try of this handler, so
				// check to see if there's already a list with that name.                                
				List targetList = GetListByTitle(listTitle, clientContext);

				// If there isn't one, create it.
				if (targetList == null)
				{
					ListCreationInformation listInfo = new ListCreationInformation();
					listInfo.Title = listTitle;
					listInfo.TemplateType = (int)ListTemplateType.GenericList;
					listInfo.Url = listTitle;
					targetList = clientContext.Web.Lists.Add(listInfo);
					clientContext.Load(targetList, l => l.Id);
					clientContext.ExecuteQuery();
					listID = targetList.Id;
				}
			}
		}
		return listID;
	}

	private void DeleteList(Guid listID, SPRemoteEventProperties properties)
	{
		using (ClientContext clientContext = TokenHelper.CreateAppEventClientContext(properties, useAppWeb: false))
		{
			if (clientContext != null)
			{
				// Check to see if the "try" block code got far enough to create the list before it errored. 
				List targetList = GetListByID(listID, clientContext);

				// If it did, delete the list.
				if (targetList != null)
				{
					targetList.DeleteObject();
					clientContext.ExecuteQuery();
				}
			}
		}
	}
	private List GetListByTitle(String listTitle, ClientContext clientContext)
	{
		ListCollection allLists = clientContext.Web.Lists;
		IEnumerable<List> matchingLists = clientContext.LoadQuery(allLists.Where(list => list.Title == listTitle));
		clientContext.ExecuteQuery();
		return matchingLists.FirstOrDefault();
	}
	private List GetListByID(Guid listID, ClientContext clientContext)
	{
		ListCollection allLists = clientContext.Web.Lists;
		IEnumerable<List> matchingLists = clientContext.LoadQuery(allLists.Where(list => list.Id == listID));
		clientContext.ExecuteQuery();
		return matchingLists.FirstOrDefault();
	}

	private void RecycleList(String title, SPRemoteEventProperties properties)
	{
		using (ClientContext clientContext = TokenHelper.CreateAppEventClientContext(properties, useAppWeb: false))
		{
			if (clientContext != null)
			{
				// Check to see that a user hasn't already recycled the list in the SharePoint UI.
				List targetList = GetListByTitle(title, clientContext);

				// If its still there, recycle it.
				if (targetList != null)
				{
					targetList.Recycle();
					clientContext.ExecuteQuery();
				}
			}
		}
	}

	private void RestoreList(String title, SPRemoteEventProperties properties)
	{
		using (ClientContext clientContext = TokenHelper.CreateAppEventClientContext(properties, useAppWeb: false))
		{
			if (clientContext != null)
			{
				// Check to see that a user hasn't manually deleted the list from the Recycle Bin
				RecycleBinItemCollection bin = clientContext.Web.RecycleBin;
				IEnumerable<RecycleBinItem> matchingItems = clientContext.LoadQuery(bin.Where(item => item.Title == title));
				clientContext.ExecuteQuery();
				RecycleBinItem recycledList = matchingItems.FirstOrDefault();

				// If it is there, restore it. 
				if (recycledList != null)
				{
					recycledList.Restore();
					clientContext.ExecuteQuery();
				}
			}
		}
	}
}

Full example code: https://github.com/SharePoint/PnP/tree/master/Samples/Core.AppEvents

Best Regards,

Dennis

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