Bulk Upload Files to SharePoint remotely using CSOM in SharePoint Online

Bulk Upload Files to SharePoint remotely using CSOM in SharePoint Online
Using PowerShell: https://gallery.technet.microsoft.com/PowerShell-Bulk-Upload-b9e9d600
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using Microsoft.SharePoint.Client;

using SP = Microsoft.SharePoint.Client;

using System;

using System.IO;

using System.Linq;

using System.Security;

namespace WebApplication1

{

    public partial class WebForm1 : System.Web.UI.Page

    {

        const string webUrl = "https://sreekanth2.sharepoint.com/";

        const string USER = "sreekanth@sreekanth2.onmicrosoft.com";

        const string PWD = "Password";

        const string parent_dir = @"D:\ToUploadFilesFolder";

        const string listTitle = "MyDocuments"; // Library Display Name and Url should be same.

        public string parent_folderName = "";

        public string sub_folderName = "";

        public string fileName = "";

        public string file_relativeUrl = "";

        protected void Page_Load(object sender, EventArgs e)

        {

            using (ClientContext clientContext = new ClientContext(webUrl))

            {

                SecureString passWord = new SecureString();

                foreach (char c in PWD.ToCharArray())

                {

                    passWord.AppendChar(c);

                }

                clientContext.Credentials = new SharePointOnlineCredentials(USER, passWord);

                var arrayfolderName = parent_dir.Split(new char[] { '\\' }, StringSplitOptions.RemoveEmptyEntries);

                parent_folderName = arrayfolderName[arrayfolderName.Length - 1];

                if (!FolderExists(clientContext.Web, listTitle, parent_folderName))

                {

                    CreateFolder(clientContext.Web, listTitle, parent_folderName);

                }

                DirSearch(clientContext, parent_dir);

            }

        }

        private void DirSearch(ClientContext clientContext, string dir)

        {

            try

            {

                foreach (string f in Directory.GetFiles(dir))

                {

                    fileName = f.Split(new string[] { dir }, StringSplitOptions.RemoveEmptyEntries)[0].Replace("\\", "/");

                    file_relativeUrl = parent_folderName + "/" + f.Split(new string[] { parent_dir + "\\" }, StringSplitOptions.RemoveEmptyEntries)[0].Replace("\\", "/");

                    //div1.InnerHtml += "/" + file_relativeUrl + "</br>";

                    using (FileStream fs = new FileStream(dir + "\\" + fileName, FileMode.Open))

                    {

                        SP.File.SaveBinaryDirect(clientContext, "/" + listTitle + "/" + file_relativeUrl, fs, true);

                    }

                }

                foreach (string d in Directory.GetDirectories(dir))

                {

                    sub_folderName = d.Split(new string[] { parent_dir + "\\" }, StringSplitOptions.RemoveEmptyEntries)[0].Replace("\\", "/");

                    //div1.InnerHtml += parent_folderName + "/" + sub_folderName + "</br>";

                    if (!FolderExists(clientContext.Web, listTitle, parent_folderName + "/" + sub_folderName))

                    {

                        CreateFolder(clientContext.Web, listTitle, parent_folderName + "/" + sub_folderName);

                    }

                    DirSearch(clientContext, d);

                }

            }

            catch (System.Exception ex)

            {

                div1.InnerHtml += ex.Message + " " + ex.StackTrace;

            }

        }

        public static bool FolderExists(Web web, string listTitle, string folderUrl)

        {

            var list = web.Lists.GetByTitle(listTitle);

            var folders = list.GetItems(CamlQuery.CreateAllFoldersQuery());

            web.Context.Load(list.RootFolder);

            web.Context.Load(folders);

            web.Context.ExecuteQuery();

            var folderRelativeUrl = string.Format("/{0}/{1}", list.RootFolder.Name, folderUrl);

            return Enumerable.Any(folders, folderItem => (string)folderItem["FileRef"] == folderRelativeUrl);

        }

        private static void CreateFolder(Web web, string listTitle, string folderName)

        {

            var list = web.Lists.GetByTitle(listTitle);

            var folderCreateInfo = new ListItemCreationInformation

            {

                UnderlyingObjectType = FileSystemObjectType.Folder,

                LeafName = folderName

            };

            var folderItem = list.AddItem(folderCreateInfo);

            folderItem.Update();

            web.Context.ExecuteQuery();

        }

    }

}

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