如何在使用Sharepoint CSOM调用GetItemById时获取AttachmentFiles？

我想花一点时间来记录一个问题，我在尝试获取AttachmentFiles时解决了这个问题，同时使用用于Sharepoint的.NET客户端对象模型（CSOM），特别是Microsoft.Sharepoint.Client，使用GetItemById。我找不到这个问题的明确答案。以下是获取Sharepoint列表项的基本方法，您可以在MSDN任何其他网站上找到该方法：

var siteUrl = "http://MyServer/sites/MySiteCollection";

var clientContext = new ClientContext(siteUrl);
var site = clientContext.Web;
var targetList = site.Lists.GetByTitle("Announcements");

var targetListItem = targetList.GetItemById(4);

clientContext.Load(targetListItem, item => item["Title"]);
clientContext.ExecuteQuery();

Console.WriteLine("Retrieved item is: {0}", targetListItem["Title"]);

// This will throw an AttachmentFiles "Not Initialized" Error
Console.WriteLine("AttachmentFiles count is: {0}", targetListItem.AttachmentFiles.Count);

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我现在将发布如何在下面的答案中正确包含附件：

以下是正确的方法：

var siteUrl = "http://MyServer/sites/MySiteCollection";

var clientContext = new ClientContext(siteUrl);
var site = clientContext.Web;
var targetList = site.Lists.GetByTitle("Announcements");

var targetListItem = targetList.GetItemById(4);
var attachments = targetListItem.AttachmentFiles;

clientContext.Load(targetListItem, item => item["Title"]);
clientContext.Load(attachments)
clientContext.ExecuteQuery();

Console.WriteLine("Retrieved item is: {0}", targetListItem["Title"]);   
// This will no longer throw the error 
Console.WriteLine("AttachmentFiles count is: {0}", targetListItem.AttachmentFiles.Count);

---

以下是正确的方法：

var siteUrl = "http://MyServer/sites/MySiteCollection";

var clientContext = new ClientContext(siteUrl);
var site = clientContext.Web;
var targetList = site.Lists.GetByTitle("Announcements");

var targetListItem = targetList.GetItemById(4);
var attachments = targetListItem.AttachmentFiles;

clientContext.Load(targetListItem, item => item["Title"]);
clientContext.Load(attachments)
clientContext.ExecuteQuery();

Console.WriteLine("Retrieved item is: {0}", targetListItem["Title"]);   
// This will no longer throw the error 
Console.WriteLine("AttachmentFiles count is: {0}", targetListItem.AttachmentFiles.Count);