从共享点文件打开文件流

Question

我想从共享点文件 (Microsoft.SharePoint.Client.File) 打开文件流，但我似乎不知道如何操作。

我只能访问Microsoft.SharePoint.Client，因为Microsoft.SharePoint包由于一些错误无法安装。

这是我目前的代码：

ClientContext ctx = new ClientContext("https://factionxyz0.sharepoint.com/sites/faktion-devs");
ctx.Credentials = CredentialCache.DefaultCredentials;
Microsoft.SharePoint.Client.File temp = ctx.Web.GetFileByServerRelativeUrl(filePath);
FileStream fs = new FileStream(???);

Answer 1

如果文件存在于物理磁盘上（或通过操作系统映射到磁盘），您只能创建 System.IO.FileStream。

解决方法：您是否能够访问文件的原始 URL？在这种情况下，将文件下载到磁盘（如果大小合适），然后从那里读取。

例如：

var httpClient = new HttpClient();

// HTTP GET Request
var response = await httpClient.GetAsync(... SharePoint URL ...);

// Get the Content Stream
var stream = await response.Content.ReadAsSteamAsync();


// Create a temporary file
var tempFile = Path.GetTempFileName();

using (var fs = File.OpenWrite(tempFile))
{
   await stream.CopyToAsync(fs);
}

// tempFile now contains your file locally, you can access it like
var fileStream = File.OpenRead(tempFile);

// Make sure you delete the temporary file after using it
File.Delete(tempFile);

Answer 2

FileStream 必须映射到文件。以下代码演示了如何通过 CSOM 获取流，然后我们可以使用临时文件将其转换为 FileStream。

ResourcePath filepath = ResourcePath.FromDecodedUrl(filename);

Microsoft.SharePoint.Client.File temp = context.Web.GetFileByServerRelativePath(filepath);

ClientResult<System.IO.Stream> crstream = temp.OpenBinaryStream();

context.Load(temp);
context.ExecuteQuery();

var tempFile = Path.GetTempFileName();
FileStream fs = System.IO.File.OpenWrite(tempFile);

if (crstream.Value != null){
      crstream.Value.CopyTo(fs);
}

关于 Azure 函数临时存储，您可以参考以下线程： Azure Functions Temp storage 或者，您可以将数据存储到 Azure 存储： Upload data to blob storage with Azure Functions

最好的问候， 贝克岗

Answer 3

自从提出问题以来已经有一段时间了，但是，这就是我在处理项目时解决这个问题的方法。显然，像这样直接传递凭据不是最好的方法，但由于时间限制，我无法将此项目转换为较新版本的 .NET 并使用 Azure AD。

请注意，该类正在实现一个接口。

public void SetServer(string domainName) {
    if (string.IsNullOrEmpty(domainName)) throw new Exception("Invalid domain name. Name cannot be null");
    _server = domainName.Trim('/').Trim('\\');
}

private string MapPath(string urlPath) {
    var url = string.Join("/", _server, urlPath);
    return url.Trim('/');
}

public ISharePointDocument GetDocument(string path, string fileName) {
    var serverPath = MapPath(path);
    var filePath = string.Join("/", serverPath, TemplateLibrary, fileName).Trim('/');
    var document = new SharePointDocument();
    var data = GetClientStream(path, fileName);

    using(var memoryStream = new MemoryStream()) {
        if (data == null) return document;
        data.CopyTo(memoryStream);
        var byteArray = memoryStream.ToArray();
        document = new SharePointDocument {
            FullPath = filePath,
            Bytes = byteArray
        };
    }

    return document;
}

public Stream GetClientStream(string path, string fileName) {
    var serverPath = MapPath(path);
    var filePath = string.Join("/", serverPath, TemplateLibrary, fileName).Trim('/');
    var context = GetClientContext(serverPath);

    var web = context.Web;

    context.Load(web);
    context.ExecuteQuery();

    var file = web.GetListItem(filePath).File;
    var data = file.OpenBinaryStream();

    context.Load(file);
    context.ExecuteQuery();

    return data.Value;
}

private static ClientContext GetClientContext(string serverPath) {
    var context = new ClientContext(serverPath) {
        Credentials = new SharePointOnlineCredentials("example@example.com", GetPassword())
    };

    return context;
}

private static SecureString GetPassword() {
    const string password = "XYZ";
    var securePassword = new SecureString();

    foreach(var c in password.ToCharArray()) securePassword.AppendChar(c);

    return securePassword;
}