c# - How can I scan a document using ASP.net MVC 5 with the help of Twain

Question

Please help me out by sharing the step by step procedure to achieve the scanning functionality using Twain in ASP.Net MVC5. Thank you

Answer 1

Solution is here:

1. In ASP.Net/Core Project you send message to call winform project:

           var start = function () {
           var i = 0;
           var wsImpl = window.WebSocket || window.MozWebSocket;
           window.ws = new wsImpl('ws://localhost:8181/');
           ws.onmessage = function (e) {
               $('#submit').hide();
               $('#scanBtn').hide();
               $('.loader').show();
               if (typeof e.data === "string") {
                   //IF Received Data is String
               }
               else if (e.data instanceof ArrayBuffer) {
                   //IF Received Data is ArrayBuffer
               }
               else if (e.data instanceof Blob) {
                   i++;
                   var f = e.data;
                   f.name = "File" + i;
                   storedFiles.push(f);
                   formdata.append(f.name, f);
                   var reader = new FileReader();
                   reader.onload = function (e) {
                       var html = "<div class="col-sm-2 text-center" 
                   style="border: 1px solid black; margin-left: 2px;"><img 
                   height="200px" width="200px" src="" + e.target.result + "" 
                   data-file='" + f.name + "' class='selFile' title='Click to 
                   remove'><br/>" + i + "</div>";
                       selDiv.append(html);
                       $('#submit').show();
                       $('#scanBtn').show();
                       $('.loader').hide();
                   }
                   reader.readAsDataURL(f);
               }
           };
           ws.onopen = function () {
               //Do whatever u want when connected succesfully
           };
           ws.onclose = function () {
               $('.dalert').modal('show');
           };
       }
       window.onload = start;
       function scanImage() {
           ws.send("1100");
       };
   

https://javascript.info/websocket

2. In Winforms Project you scan document and send graphic data back to Asp.Net/Core project:

   public partial class Form1 : Form { ImageCodecInfo _tiffCodecInfo; TwainSession _twain; bool _stopScan; bool _loadingCaps; List allSockets; WebSocketServer server; public Form1() { InitializeComponent();

    if (NTwain.PlatformInfo.Current.IsApp64Bit)
   {
       Text = Text + " (64bit)";
   }
   else
   {
       Text = Text + " (32bit)";
   }
   foreach (var enc in ImageCodecInfo.GetImageEncoders())
   {
       if (enc.MimeType == "image/tiff") { _tiffCodecInfo = enc; break; }
   }
   
   this.WindowState = FormWindowState.Minimized;
   this.ShowInTaskbar = false;
   
   allSockets = new List<IWebSocketConnection>();
   server = new WebSocketServer("ws://0.0.0.0:8181");
   server.Start(socket =>
   {
       socket.OnOpen = () =>
       {
           Console.WriteLine("Open!");
           allSockets.Add(socket);
       };
       socket.OnClose = () =>
       {
           Console.WriteLine("Close!");
           allSockets.Remove(socket);
       };
       socket.OnMessage = message =>
       {
           if (message == "1100")
           {
               this.Invoke(new Action(()=> {
                   this.WindowState = FormWindowState.Normal;
               }));
           }
       };
   });
   

   }

Link to project.

https://github.com/mgriit/ScanAppForWeb

You can remake this project, as you want.