如何使用CSOM从/向SharePoint 2013下载/上载文件？

Question

我正在开发一个Win8(WinRT,C#,XAML)客户端应用程序(CSOM),需要从/向SharePoint 2013下载/上载文件.

如何进行下载/上传？

Answer 1

上传一个文件

使用File.SaveBinaryDirect方法将文件上载到SharePoint网站(包括SharePoint Online):

using (var clientContext = new ClientContext(url))
{
     using (var fs = new FileStream(fileName, FileMode.Open))
     {
         var fi = new FileInfo(fileName);
         var list = clientContext.Web.Lists.GetByTitle(listTitle);
         clientContext.Load(list.RootFolder);
         clientContext.ExecuteQuery();
         var fileUrl = String.Format("{0}/{1}", list.RootFolder.ServerRelativeUrl, fi.Name);

         Microsoft.SharePoint.Client.File.SaveBinaryDirect(clientContext, fileUrl, fs, true);
     }
}

下载文件

使用File.OpenBinaryDirect方法从SharePoint网站(包括SharePoint Online)下载文件:

using (var clientContext = new ClientContext(url))
{

     var list = clientContext.Web.Lists.GetByTitle(listTitle);
     var listItem = list.GetItemById(listItemId);
     clientContext.Load(list);
     clientContext.Load(listItem, i => i.File);
     clientContext.ExecuteQuery();

     var fileRef = listItem.File.ServerRelativeUrl;
     var fileInfo = Microsoft.SharePoint.Client.File.OpenBinaryDirect(clientContext, fileRef);
     var fileName = Path.Combine(filePath,(string)listItem.File.Name);
     using (var fileStream = System.IO.File.Create(fileName))
     {                  
          fileInfo.Stream.CopyTo(fileStream);
     }
}

Answer 2

该文章描述了访问SharePoint内容的各种选项.您可以选择REST和CSOM.如果可能,我会尝试CSOM.上传/下载文件特别是很好地描述了这个文章.

总体说明:

    //First construct client context, the object which will be responsible for
    //communication with SharePoint:
    var context = new ClientContext(@"http://site.absolute.url")

    //then get a hold of the list item you want to download, for example
    var list = context.Web.Lists.GetByTitle("Pipeline");
    var query = CamlQuery.CreateAllItemsQuery(10000);
    var result = list.GetItems(query);

    //note that data has not been loaded yet. In order to load the data
    //you need to tell SharePoint client what you want to download:

    context.Load(result, items=>items.Include(
        item => item["Title"],
        item => item["FileRef"]
    ));

    //now you get the data
    context.ExecuteQuery();

    //here you have list items, but not their content (files). To download file
    //you'll have to do something like this:

    var item = items.First();

    //get the URL of the file you want:
    var fileRef = item["FileRef"];

    //get the file contents:
    FileInformation fileInfo = File.OpenBinaryDirect(context, fileRef.ToString());

    using (var memory = new MemoryStream())
    {
          byte[] buffer = new byte[1024 * 64];
          int nread = 0;
          while ((nread = fileInfo.Stream.Read(buffer, 0, buffer.Length)) > 0)
          {
              memory.Write(buffer, 0, nread);
          }
          memory.Seek(0, SeekOrigin.Begin);
          // ... here you have the contents of your file in memory, 
          // do whatever you want
    }

避免直接使用流,首先将其读入内存.网络绑定流不一定支持流操作,更不用说性能.因此,如果您正在从该流中读取图片或解析文档,您可能会遇到一些意外行为.

在旁注中,我有一个相关的问题:上面这段代码的性能,因为你对每个文件请求都会受到一些惩罚.看到这里.是的,你需要4.5完整的.NET配置文件.

Answer 3

在当您使用OAuth accestoken File.OpenBinaryDirect可能会造成异常的解释此文章

代码应写如下,以避免例外

 Uri filename = new Uri(filepath);
        string server = filename.AbsoluteUri.Replace(filename.AbsolutePath, 
         "");
        string serverrelative = filename.AbsolutePath;

        Microsoft.SharePoint.Client.File file = 
        this.ClientContext.Web.GetFileByServerRelativeUrl(serverrelative);
        this.ClientContext.Load(file);
        ClientResult<Stream> streamResult = file.OpenBinaryStream();
        this.ClientContext.ExecuteQuery();
        return streamResult.Value;

Answer 4

这个评论有点晚了，但我会在这里留下我使用 SharePoin Online 库的结果，它很容易在您的项目中使用和实施，只需转到 .Net 的 NuGet 管理员并将 Microsoft.SharePoint.CSOM 添加到您的项目 。

[https://developer.microsoft.com/en-us/office/blogs/new-sharepoint-csom-version-released-for-office-365-may-2017/][1]

以下代码片段将帮助您将凭据连接到 SharePoint 站点，您还可以从特定站点和文件夹读取和下载文件。

using System;
using System.IO;
using System.Linq;
using System.Web;
using Microsoft.SharePoint.Client;
using System.Security;

using ClientOM = Microsoft.SharePoint.Client;

namespace MvcApplication.Models.Home
{
    public class SharepointModel
    {
        public ClientContext clientContext { get; set; }
        private string ServerSiteUrl = "https://somecompany.sharepoint.com/sites/ITVillahermosa";
        private string LibraryUrl = "Shared Documents/Invoices/";
        private string UserName = "someone.surname@somecompany.com";
        private string Password = "********";
        private Web WebClient { get; set; }

        public SharepointModel()
        {
            this.Connect();
        }

        public void Connect()
        {
            try
            {
                using (clientContext = new ClientContext(ServerSiteUrl))
                {
                    var securePassword = new SecureString();
                    foreach (char c in Password)
                    {
                        securePassword.AppendChar(c);
                    }

                    clientContext.Credentials = new SharePointOnlineCredentials(UserName, securePassword);
                    WebClient = clientContext.Web;
                }
            }
            catch (Exception ex)
            {
                throw (ex);
            }
        }

        public string UploadMultiFiles(HttpRequestBase Request, HttpServerUtilityBase Server)
        {
            try
            {
                HttpPostedFileBase file = null;
                for (int f = 0; f < Request.Files.Count; f++)
                {
                    file = Request.Files[f] as HttpPostedFileBase;

                    string[] SubFolders = LibraryUrl.Split('/');
                    string filename = System.IO.Path.GetFileName(file.FileName);
                    var path = System.IO.Path.Combine(Server.MapPath("~/App_Data/uploads"), filename);
                    file.SaveAs(path);

                    clientContext.Load(WebClient, website => website.Lists, website => website.ServerRelativeUrl);
                    clientContext.ExecuteQuery();

                    //https://somecompany.sharepoint.com/sites/ITVillahermosa/Shared Documents/
                    List documentsList = clientContext.Web.Lists.GetByTitle("Documents"); //Shared Documents -> Documents
                    clientContext.Load(documentsList, i => i.RootFolder.Folders, i => i.RootFolder);
                    clientContext.ExecuteQuery();

                    string SubFolderName = SubFolders[1];//Get SubFolder 'Invoice'
                    var folderToBindTo = documentsList.RootFolder.Folders;
                    var folderToUpload = folderToBindTo.Where(i => i.Name == SubFolderName).First();

                    var fileCreationInformation = new FileCreationInformation();
                    //Assign to content byte[] i.e. documentStream
                    fileCreationInformation.Content = System.IO.File.ReadAllBytes(path);
                    //Allow owerwrite of document
                    fileCreationInformation.Overwrite = true;
                    //Upload URL
                    fileCreationInformation.Url = ServerSiteUrl + LibraryUrl + filename;

                    Microsoft.SharePoint.Client.File uploadFile = documentsList.RootFolder.Files.Add(fileCreationInformation);

                    //Update the metadata for a field having name "DocType"
                    uploadFile.ListItemAllFields["Title"] = "UploadedCSOM";

                    uploadFile.ListItemAllFields.Update();
                    clientContext.ExecuteQuery();
                }

                return "";
            }
            catch (Exception ex)
            {
                throw (ex);
            }
        }

        public string DownloadFiles()
        {
            try
            {
                string tempLocation = @"c:\Downloads\Sharepoint\";
                System.IO.DirectoryInfo di = new DirectoryInfo(tempLocation);
                foreach (FileInfo file in di.GetFiles())
                {
                    file.Delete();
                }

                FileCollection files = WebClient.GetFolderByServerRelativeUrl(this.LibraryUrl).Files;
                clientContext.Load(files);
                clientContext.ExecuteQuery();

                if (clientContext.HasPendingRequest)
                    clientContext.ExecuteQuery();

                foreach (ClientOM.File file in files)
                {
                    FileInformation fileInfo = ClientOM.File.OpenBinaryDirect(clientContext, file.ServerRelativeUrl);
                    clientContext.ExecuteQuery();

                    var filePath = tempLocation + file.Name;
                    using (var fileStream = new System.IO.FileStream(filePath, System.IO.FileMode.Create))
                    {
                        fileInfo.Stream.CopyTo(fileStream);
                    }
                }

                return "";
            }
            catch (Exception ex)
            {
                throw (ex);
            }
        }

    }
}

然后在这种情况下从控制器调用函数，MVC ASP.NET 按以下方式完成。

using MvcApplication.Models.Home;
using System;
using System.Web.Mvc;

namespace MvcApplication.Controllers
{
    public class SharepointController : MvcBoostraBaseController
    {
        [HttpPost]
        public ActionResult Upload(FormCollection form)
        {
            try
            {
                SharepointModel sharepointModel = new SharepointModel();
                return Json(sharepointModel.UploadMultiFiles(Request, Server), JsonRequestBehavior.AllowGet);
            }
            catch (Exception ex)
            {
                return ThrowJSONError(ex);
            }
        }

        public ActionResult Download(string ServerUrl, string RelativeUrl)
        {
            try
            {
                SharepointModel sharepointModel = new SharepointModel();
                return Json(sharepointModel.DownloadFiles(), JsonRequestBehavior.AllowGet);
            }
            catch (Exception ex)
            {
                return ThrowJSONError(ex);
            }
        }
    }
}

如果您需要此源代码，可以访问我的 github 存储库

https://github.com/israelz11/MvcBoostrapTestSharePoint/

Answer 5

我建议阅读一些 Microsoft 文档，了解如何使用 CSOM。这可能是您正在寻找的示例之一，但 msdn 中记录了一个庞大的 API。

// Starting with ClientContext, the constructor requires a URL to the 
// server running SharePoint. 
ClientContext context = new ClientContext("http://SiteUrl"); 

// Assume that the web has a list named "Announcements". 
List announcementsList = context.Web.Lists.GetByTitle("Announcements"); 

// Assume there is a list item with ID=1. 
ListItem listItem = announcementsList.Items.GetById(1); 

// Write a new value to the Body field of the Announcement item.
listItem["Body"] = "This is my new value!!"; 
listItem.Update(); 

context.ExecuteQuery(); 

来自： http: //msdn.microsoft.com/en-us/library/fp179912.aspx