How to download/upload files from/to SharePoint 2013 using CSOM?

Question

I am developing a Win8 (WinRT, C#, XAML) client application (CSOM) that needs to download/upload files from/to SharePoint 2013.

How do I do the Download/Upload?

Answer 1

This article describes various options for accessing SharePoint content. You have a choice between REST and CSOM. I'd try CSOM if possible. File upload / download specifically is nicely described in this article.

Overall notes:

    //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
    }

Avoid working with the stream directly, read it into the memory first. Network-bound streams are not necessarily supporting stream operations, not to mention performance. So, if you are reading a pic from that stream or parsing a document, you may end up with some unexpected behavior.

On a side note, I have a related question re: performance of this code above, as you are taking some penalty with every file request. See here. And yes, you need 4.5 full .NET profile for this.

Answer 2

File.OpenBinaryDirect may cause exception when you are using Oauth accestoken Explained in This Article

Code should be written as below to avoid exceptions

 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 3

Private Sub DownloadFile(relativeUrl As String, destinationPath As String, name As String)
    Try
        destinationPath = Replace(destinationPath + "\" + name, "\\", "\")
        Dim fi As FileInformation = Microsoft.SharePoint.Client.File.OpenBinaryDirect(Me.context, relativeUrl)
        Dim down As Stream = System.IO.File.Create(destinationPath)
        Dim a As Integer = fi.Stream.ReadByte()
        While a <> -1
            down.WriteByte(CType(a, Byte))
            a = fi.Stream.ReadByte()
        End While
    Catch ex As Exception
        ToLog(Type.ERROR, ex.Message)
    End Try
End Sub

Answer 4

Just a suggestion SharePoint 2013 online & on-prem file encoding is UTF-8 BOM. Make sure your file is UTF-8 BOM, otherwise your uploaded html and scripts may not rendered correctly in browser.

Answer 5

I would suggest reading some Microsoft documentation on what you can do with CSOM. This might be one example of what you are looking for, but there is a huge API documented in msdn.

// 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(); 

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

Answer 6

Upload a file

Upload a file to a SharePoint site (including SharePoint Online) using File.SaveBinaryDirect Method:

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);
     }
}

Download file

Download file from a SharePoint site (including SharePoint Online) using File.OpenBinaryDirect Method:

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);
     }
}