Sharepoint API - How to Upload files to Sharepoint Doc Library from ASP.NET Web Application

You can write some custom code to do it. You could use the SharePoint API if you are on the same server or use WebServices

Here is the sample code assuming that you know the url of the document library and you are uploading the document to the root folder. You will have to add Microsoft.SharePoint.dll as reference to your ASP.NET project

        using (SPSite siteCollection = new SPSite(url))
        {
            using (SPWeb spWeb = siteCollection.OpenWeb())
            {
                SPList spList = spWeb.GetList(url);

                string fileName = "XXXX";
                FileStream fileStream = null;
                Byte[] fileContent = null;

                try
                {
                    string docPath = XXXX; //physical location of the file
                    fileStream = File.OpenRead(docPath + fileName);
                    fileContent = new byte[Convert.ToInt32(fileStream.Length)];
                    fileStream.Read(fileContent, 0, Convert.ToInt32(fileStream.Length));

                    spList.RootFolder.Files.Add(spList.RootFolder.Url + "/" + fileName, fileContent, true);
                    spList.Update();
                }
                catch(Exception ex)
                {

                }
                finally
                {
                    if (fileStream != null)
                    {
                        fileStream.Close();
                    }
                }
            }
        }

look at this blog post. By Bil Simser.

There seemed to be a lot of argument about using Web Services, lists, and all that just to upload a document. It can't be that hard. After spending a little time on Google (google IS your friend) I found various attempts at uploading documents through regular HTTP PUT commands. Here's the one that finally worked in a simple, single function:...