.NET Document Scanner for TWAIN, WIA, SANE, ICA, and eSCL

The package provides methods for calling Dynamsoft Service REST APIs. This allows developers to build .NET applications for digitizing documents from TWAIN (32-bit/64-bit), WIA, SANE, ICA and eSCL scanners.

dotnet-twain-document-scan.mp4

Prerequisites

1. Install Dynamsoft Service.

   • Windows: Dynamsoft-Service-Setup.msi
   • macOS: Dynamsoft-Service-Setup.pkg
   • Linux:
     • Dynamsoft-Service-Setup.deb
     • Dynamsoft-Service-Setup-arm64.deb
     • Dynamsoft-Service-Setup-mips64el.deb
     • Dynamsoft-Service-Setup.rpm

2. Request a free trial license.

Dynamsoft Service REST API

By default, the REST API's host address is set to http://127.0.0.1:18622.

Method	Endpoint	Description	Parameters	Response
GET	/DWTAPI/Scanners	Get a list of scanners	None	200 OK with scanner list
POST	/DWTAPI/ScanJobs	Creates a scan job	license, device, config	201 Created with job ID
GET	/DWTAPI/ScanJobs/:id/NextDocument	Retrieves a document image	id: Job ID	200 OK with image stream
DELETE	/DWTAPI/ScanJobs/:id	Deletes a scan job	id: Job ID	200 OK

You can navigate to http://127.0.0.1:18625/ to access the service. To make it accessible from desktop, mobile, and web applications on the same network, you can change the host address to a LAN IP address. For example, you might use http://192.168.8.72.

The scanner parameter configuration is based on Dynamsoft Web TWAIN documentation.

Quick Start

Replace the license key in the code below with a valid one and run the code.

using System;
using System.Collections.Generic;
using Twain.Wia.Sane.Scanner;

public class Program
{
    private static string licenseKey = "LICENSE-KEY";
    private static ScannerController scannerController = new ScannerController();
    private static List<Dictionary<string, object>> devices = new List<Dictionary<string, object>>();
    private static string host = "http://127.0.0.1:18622";
    private static string questions = @"
Please select an operation:
1. Get scanners
2. Acquire documents by scanner index
3. Quit
";

    public static async Task Main()
    {
        await AskQuestion();
    }

    private static async Task<int> AskQuestion()
    {
        while (true)
        {
            Console.WriteLine(".............................................");
            Console.WriteLine(questions);
            string? answer = Console.ReadLine();

            if (string.IsNullOrEmpty(answer))
            {
                continue;
            }

            if (answer == "3")
            {
                break;
            }
            else if (answer == "1")
            {
                var scanners = await scannerController.GetDevices(host, ScannerType.TWAINSCANNER | ScannerType.TWAINX64SCANNER);
                devices.Clear();
                for (int i = 0; i < scanners.Count; i++)
                {
                    var scanner = scanners[i];
                    devices.Add(scanner);
                    Console.WriteLine($"\nIndex: {i}, Name: {scanner["name"]}");
                }
            }
            else if (answer == "2")
            {
                if (devices.Count == 0)
                {
                    Console.WriteLine("Please get scanners first!\n");
                    continue;
                }

                Console.Write($"\nSelect an index (<= {devices.Count - 1}): ");
                int index;
                if (!int.TryParse(Console.ReadLine(), out index))
                {
                    Console.WriteLine("Invalid input. Please enter a number.");
                    continue;
                }

                if (index < 0 || index >= devices.Count)
                {
                    Console.WriteLine("It is out of range.");
                    continue;
                }

                var parameters = new Dictionary<string, object>
                {
                    {"license", licenseKey},
                    {"device", devices[index]["device"]}
                };

                parameters["config"] = new Dictionary<string, object>
                {
                    {"IfShowUI", false},
                    {"PixelType", 2},
                    {"Resolution", 200},
                    {"IfFeederEnabled", false},
                    {"IfDuplexEnabled", false}
                };

                var text = await scannerController.ScanDocument(host, parameters);
                string jobId = "";
                if (text.ContainsKey(ScannerController.SCAN_SUCCESS))
                {
                    jobId = text[ScannerController.SCAN_SUCCESS];
                }

                string error = "";
                if (text.ContainsKey(ScannerController.SCAN_ERROR))
                {
                    error = text[ScannerController.SCAN_ERROR];
                }

                if (!string.IsNullOrEmpty(jobId))
                {
                    var images = await scannerController.GetImageFiles(host, jobId, "./");
                    for (int i = 0; i < images.Count; i++)
                    {
                        Console.WriteLine($"Image {i}: {images[i]}");
                    }

                    scannerController.DeleteJob(host, jobId);
                }
                else if (!string.IsNullOrEmpty(error))
                {
                    Console.WriteLine($"Error: {error}");
                }
            }
            else
            {
                continue;
            }
        }
        return 0;
    }
}

Example

• command-line

• .NET MAUI

  

• WinForm

  

API

• public async Task<List<Dictionary<string, object>>> GetDevices(string host, int? scannerType = null): Get a list of available devices.
• public async Task<HttpResponseMessage> GetDevicesHttpResponse(string host, int? scannerType = null): Return the HTTP response of getting devices.
• public async Task<Dictionary<string, string>> ScanDocument(string host, Dictionary<string, object> parameters): Initiate the scanner operation and return a dictionary containing either the job ID or an error message.
• public async Task<HttpResponseMessage> ScanDocumentHttpResponse(string host, Dictionary<string, object> parameters): Return the HTTP response of initiating the scanner operation.
• public async Task<HttpResponseMessage> DeleteJob(string host, string jobId): Return the HTTP response of deleting a job.
• public async Task<string> GetImageFile(string host, string jobId, string directory): Get an image file.
• public async Task<List<string>> GetImageFiles(string host, string jobId, string directory): Get a list of image files.
• public async Task<List<byte[]>> GetImageStreams(string host, string jobId): Get a list of image streams.
• public async Task<<byte[]> GetImageStream(string host, string jobId): Get an image stream.
• public async Task<HttpResponseMessage> GetImageStreamHttpResponse(string host, string jobId) : Return the HTTP response of getting an image stream.

Build the NuGet Package

dotnet build --configuration Release