在 C# 中，如果 SharePoint 网站上不存在文件夹，如何创建该文件夹

Question

我正在尝试在 C# 中创建一个微服务，它将接受一个包含订单号的 csv 文件，消化 csv，连接到 sharepoint，在 sharepoint 上创建一个新文件夹，然后从任何位置复制名称与订单号对应的合同它们可能（并且它们可能不会都在 smae 位置）到新文件夹。

此时，在 Stackoverflow 的帮助下，我可以使用 CSOM Authentication Manager 从我们的 Sharepoint 成功获取身份验证令牌。现在我想弄清楚如何创建一个文件夹。谷歌搜索有关创建 Sharepoint 文件夹的信息不断提出列表的主题，我对此一无所知，甚至不知道我是否真的想要或需要知道任何事情，或者是否有不同的工作方式与网站，因为那是我真正感兴趣的。

所以，假设我有一个位于 https://example.sharepoint.com/sites/MySite 的共享点站点。

如何在“共享文档”中存在的名为“Bar”的文件夹中简单地创建一个名为“Foo”的文件夹？

如果我需要了解一些有关列表的信息才能执行此操作，我可以使用 C# 来查找正确的列表吗？还是我需要向我的管理员询问更多信息？

Answer 1

假设 AuthenticationManager 返回一个有效的上下文并且根文件夹已经存在，下面的工作：

using Microsoft.SharePoint.Client;
using System;
using System.Collections.Generic;
using System.Linq;
using AuthenticationManager = SharepointOrderContractExtractor.Clients.AuthenticationManager;

namespace SharePointOrderContractExtractor.Clients
{
    public class FolderManager
    {
        private readonly AuthenticationManager _authenticationManager;

        public FolderManager(
            AuthenticationManager sharepointAuthenticationManager
            )
        {
            _authenticationManager = sharepointAuthenticationManager;
        }

        internal Folder EnsureAndGetTargetFolder(string folderPath)
        {
            using ClientContext context = _authenticationManager.GetContext();

            List<string> folderNames = folderPath.Split("/").ToList();
            List documents = context.Web.Lists.GetByTitle(folderNames[0]);
            folderNames.RemoveAt(0);

            return EnsureAndGetTargetFolder(context, documents, folderNames);
        }

        private Folder EnsureAndGetTargetFolder(ClientContext context, List list, List<string> folderPath)
        {
            Folder returnFolder = list.RootFolder;
            return (folderPath != null && folderPath.Count > 0)
                ? EnsureAndGetTargetSubfolder(context, list, folderPath)
                : returnFolder;
        }

        private Folder EnsureAndGetTargetSubfolder(ClientContext context, List list, List<string> folderPath)
        {
            Web web = context.Web;
            Folder currentFolder = list.RootFolder;
            context.Load(web, t => t.Url);
            context.Load(currentFolder);
            context.ExecuteQuery();

            foreach (string folderPointer in folderPath)
            {
                currentFolder = FindOrCreateFolder(context, list, currentFolder, folderPointer);
            }

            return currentFolder;
        }

        private Folder FindOrCreateFolder(ClientContext context, List list, Folder currentFolder, string folderPointer)
        {
            FolderCollection folders = currentFolder.Folders;
            context.Load(folders);
            context.ExecuteQuery();

            foreach (Folder existingFolder in folders)
            {
                if (existingFolder.Name.Equals(folderPointer, StringComparison.InvariantCultureIgnoreCase))
                {
                    return existingFolder;
                }
            }

            return CreateFolder(context, list, currentFolder, folderPointer);
        }

        private Folder CreateFolder(ClientContext context, List list, Folder currentFolder, string folderPointer)
        {
            ListItemCreationInformation itemCreationInfo = new ListItemCreationInformation
            {
                UnderlyingObjectType = FileSystemObjectType.Folder,
                LeafName = folderPointer,
                FolderUrl = currentFolder.ServerRelativeUrl
            };

            ListItem folderItemCreated = list.AddItem(itemCreationInfo);
            folderItemCreated.Update();

            context.Load(folderItemCreated, f => f.Folder);
            context.ExecuteQuery();

            return folderItemCreated.Folder;
        }
    }
}