C#实现从SharePoint中下载文件

.Net C#脚本实现下载SharePoint文档中General文件夹中的的Excel文件到本地，文件名为SharepointTest.xlsx，文件连接https://sharewinfobi.sharepoint.com/:x:/s/AM1000/ETN_N3UL9thJgRHDPbun0UIBe-TqD_d-TF9kQft9aOKlog?e=b2OllY%E3%80%82

该回答引用于ChatGPT：
这里提供一个使用 Microsoft.SharePoint.Client 库实现从 SharePoint 中下载文件的 C# 代码示例：

using System;
using System.IO;
using Microsoft.SharePoint.Client;

class Program
{
    static void Main(string[] args)
    {
        string siteUrl = "https://sharewinfobi.sharepoint.com/sites/AM1000";
        string libraryName = "General";
        string fileName = "SharepointTest.xlsx";
        string localFilePath = @"C:\Downloads\" + fileName;

        using (var clientContext = new ClientContext(siteUrl))
        {
            // Replace with the actual credentials of a user who has access to the SharePoint site
            var credential = new SharePointOnlineCredentials("username@domain.com", GetSecureString("password"));
            clientContext.Credentials = credential;

            var web = clientContext.Web;
            var list = web.Lists.GetByTitle(libraryName);
            var query = CamlQuery.CreateAllItemsQuery();
            query.ViewXml = "<View Scope='RecursiveAll'><Query><Where><Eq><FieldRef Name='FileLeafRef'/><Value Type='Text'>" + fileName + "</Value></Eq></Where></Query></View>";
            
            var items = list.GetItems(query);
            clientContext.Load(items, includes => includes.Include(item => item["FileLeafRef"],item => item.File));
            clientContext.ExecuteQuery();

            if (items.Count == 1)
            {
                var file = items[0].File;
                clientContext.Load(file);
                clientContext.ExecuteQuery();

                var fileInfo = Microsoft.SharePoint.Client.File.OpenBinaryDirect(clientContext, file.ServerRelativeUrl);
                using (var fileStream = new FileStream(localFilePath, FileMode.Create))
                {
                    fileInfo.Stream.CopyTo(fileStream);
                }
                Console.WriteLine("File downloaded successfully!");
            }
            else
            {
                Console.WriteLine("File not found or more than one file with the same name exists.");
            }
        }
    }

    public static System.Security.SecureString GetSecureString(string password)
    {
        var securePassword = new System.Security.SecureString();
        foreach (char c in password)
        {
            securePassword.AppendChar(c);
        }
        return securePassword;
    }
}

在上面的代码中，我们首先指定 SharePoint 网站的 URL、文档库的名称、要下载的文件名以及本地存储的路径。然后，我们使用 SharePointOnlineCredentials 类来设置用户凭据，这里需要用到 SharePoint 网站的用户名和密码。

接着，我们使用 ClientContext 对象来连接到 SharePoint 网站，并获取指定文档库中的所有项。这个查询使用了 CamlQuery，并被限制为只搜索指定的文件名。如果查询返回一个项目，我们可以打开二进制文件流并将其保存到本地文件中。

最后，我们在控制台输出成功或者失败的消息。

注意：在运行此代码之前，确保已经安装 Microsoft.SharePoint.Client 和 Microsoft.SharePoint.Client.Runtime 库。

该回答引用ChatGPT
要实现从SharePoint中下载文件，需要使用SharePointOnlineCredentials类和ClientContext类，具体步骤如下：

1. 创建一个SharePointOnlineCredentials对象并传入用户名和密码。

csharp
string username = "yourUserName";
string password = "yourPassword";
SecureString securePassword = new SecureString();
foreach (char c in password)
{
    securePassword.AppendChar(c);
}
SharePointOnlineCredentials credentials = new SharePointOnlineCredentials(username, securePassword);

2. 创建一个ClientContext对象并传入SharePoint网站的URL和凭证信息。

csharp
string siteUrl = "https://sharewinfobi.sharepoint.com/sites/AM1000";
ClientContext context = new ClientContext(siteUrl);
context.Credentials = credentials;

3. 使用ClientContext对象获取文件的URL并下载到本地。

csharp
string serverRelativeUrl = "/sites/AM1000/Shared Documents/General/SharepointTest.xlsx";
Microsoft.SharePoint.Client.File file = context.Web.GetFileByServerRelativeUrl(serverRelativeUrl);
context.Load(file);
context.ExecuteQuery();

string filePath = @"C:\temp\SharepointTest.xlsx";
using (var fileStream = System.IO.File.Create(filePath))
{
    var fileInfo = Microsoft.SharePoint.Client.File.OpenBinaryDirect(context, file.ServerRelativeUrl);
    fileInfo.Stream.CopyTo(fileStream);
}

完整代码如下：

csharp
using Microsoft.SharePoint.Client;
using System;
using System.Security;

namespace SharePointFileDownloader
{
    class Program
    {
        static void Main(string[] args)
        {
            string username = "yourUserName";
            string password = "yourPassword";
            SecureString securePassword = new SecureString();
            foreach (char c in password)
            {
                securePassword.AppendChar(c);
            }
            SharePointOnlineCredentials credentials = new SharePointOnlineCredentials(username, securePassword);

            string siteUrl = "https://sharewinfobi.sharepoint.com/sites/AM1000";
            ClientContext context = new ClientContext(siteUrl);
            context.Credentials = credentials;

            string serverRelativeUrl = "/sites/AM1000/Shared Documents/General/SharepointTest.xlsx";
            Microsoft.SharePoint.Client.File file = context.Web.GetFileByServerRelativeUrl(serverRelativeUrl);
            context.Load(file);
            context.ExecuteQuery();

            string filePath = @"C:\temp\SharepointTest.xlsx";
            using (var fileStream = System.IO.File.Create(filePath))
            {
                var fileInfo = Microsoft.SharePoint.Client.File.OpenBinaryDirect(context, file.ServerRelativeUrl);
                fileInfo.Stream.CopyTo(fileStream);
            }

            Console.WriteLine("File downloaded.");
            Console.ReadLine();
        }
    }
}

其中，需要引用Microsoft.SharePoint.Client.dll和Microsoft.SharePoint.Client.Runtime.dll这两个库。可以通过NuGet包管理器安装Microsoft.SharePointOnline.CSOM库。