无法下载Office 365 SharePoint库项目

Question

I am trying to download item that exists in Office 365 SharePoint library using WebcClient.DownloadFile() but i am getting this exception:

Exception :

The remote server returned an error: (403) Forbidden.

Sample code :

NetworkCredential credential = new NetworkCredential("username", "password", "aaa.onmicrosoft.com");
WebClient webClient = new WebClient();
webClient.Credentials = credential;
webClient.DownloadFile(@"https://aaa.sharepoint.com/testDoc/test.pdf", @"c:/test.pdf");

Answer 1

Another option would be to utilize SharePointOnlineCredentials class from SharePoint Online Client Components SDK .

SharePointOnlineCredentials class represents an object that provides credentials to access SharePoint Online resources

Prerequisites

SharePoint Online Client Components SDK

How to download a file from SharePoint Online

 public static void DownloadFile(string userName, string password, string fileUrl, string filePath)
 {
        var securePassword = new SecureString();
        foreach (var c in password)
        {
            securePassword.AppendChar(c);
        }
        using (var client = new WebClient())
        {
            client.Credentials = new SharePointOnlineCredentials(userName, securePassword);
            client.Headers.Add("X-FORMS_BASED_AUTH_ACCEPTED", "f");
            client.DownloadFile(fileUrl, filePath);
        }
}

Answer 2

You need to add a little bit to get rid of your issue, called Headers and UserAgent.

 public static void method()
        {
         //   NetworkCredential myCredentials = new NetworkCredential("username", "password", "aaa.onmicrosoft.com");
            WebClient w = new WebClient();
            var ua = "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)";
            w.Headers["Accept"] = "/";
            w.Headers.Add(HttpRequestHeader.UserAgent, ua);
            w.Credentials = myCredentials;
          w.DownloadFile(url, @"c:/name.doc"); 
        }

It downloads the file for me from the teamsite library in office 365. But it gives me a downloaded file. Only issue I have left : the file does not contain the real information you wish to download. I'm trying to solve this issue for a few days now - and this is the best result I've gotten up to now. Maybe you could help me on that with this new information. Let me know please :)

Answer 3

With a bit of help from my friends, I've managed to crack this SharePoint on-line authentication stuff :)

I was kindly pointed in the direction of this blog post from Wictor Wilén.

And my WebClient call that uses Wictors claims library code...

var claimsHelper = new MsOnlineClaimsHelper(sharepointOnlineUrl, username, password);

var client = new WebClient();
client.Headers[ "Accept" ] = "/";
client.Headers.Add(HttpRequestHeader.UserAgent, "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; .NET CLR 1.0.3705;)");
client.Headers.Add(HttpRequestHeader.Cookie, claimsHelper.CookieContainer.GetCookieHeader(new Uri(sharepointOnlineUrl))  );

var document = client.DownloadString( documentUrl );