$ dotnet new webapp -o FormRecognizer

$ cd FormRecognizer

$ dotnet run

$ dotnet add package Azure.AI.FormRecognizer

{

  "Logging": {

    "LogLevel": {

      "Default": "Information",

      "Microsoft": "Warning",

      "Microsoft.Hosting.Lifetime": "Information"

    }

  },

  "AzureFormRecognizer": {

    "EndPoint": "Your Endpoint",

    "Key": "Your Key"

  },

  "AllowedHosts": "*"

}

$ mkdir Services

$ touch Services/Recognizer.cs

using System.Threading.Tasks;

using Microsoft.Extensions.Logging;

using Microsoft.Extensions.Configuration;

using Azure;

using Azure.AI.FormRecognizer;

using Azure.AI.FormRecognizer.Models;

using Microsoft.AspNetCore.Http;

using System;

using System.IO;

using System.Linq;

using System.Text.RegularExpressions;

namespace FormRecognizer.Services

{

    public interface IRecognizer

    {

        Task RecognizeFromFile(IFormFile formFile);

    }

    public class Recognizer : IRecognizer

    {

        private readonly ILogger<Recognizer> _logger;

        private readonly FormRecognizerClient _formRecognizerClient;

        public Recognizer(ILogger<Recognizer> logger, IConfiguration configuration)

        {

            _logger = logger;

            // appsettings.jsonからFormRecognizerの資格情報を取得する

            var configs = configuration.GetSection("AzureFormRecognizer");

            var credential = new AzureKeyCredential(configs["Key"]);

            // クライアントを認証する

            _formRecognizerClient = new FormRecognizerClient(new Uri(configs["EndPoint"]), credential);

        }

        public async Task RecognizeFromFile(IFormFile formFile)

        {

            // アップロードされたファイルをMemoryStreamにコピーする

            using var stream = new MemoryStream();

            await formFile.CopyToAsync(stream);

            stream.Position = 0;

            // 請求書読み取りを実行する

            var options = new RecognizeInvoicesOptions() { Locale = "en-US" };

            RecognizeInvoicesOperation operation = await _formRecognizerClient.StartRecognizeInvoicesAsync(stream, options);

            Response<RecognizedFormCollection> operationResponse = await operation.WaitForCompletionAsync();

            RecognizedFormCollection invoices = operationResponse.Value;

            // 読み取り結果を処理する

            RecognizedForm invoice = invoices.Single();

            _logger.LogInformation($"Invoice File : '{formFile.FileName}'");

            // 請求金額

            if (invoice.Fields.TryGetValue("InvoiceTotal", out FormField invoiceTotalField))

            {

                if (invoiceTotalField.Value.ValueType == FieldValueType.Float)

                {

                    float invoiceTotal = invoiceTotalField.Value.AsFloat();

                    _logger.LogInformation($"Invoice Total: '{invoiceTotal}', with confidence {invoiceTotalField.Confidence}");

                }

            }

            // 発行日

            if (invoice.Fields.TryGetValue("InvoiceDate", out FormField invoiceDateField))

            {

                if (invoiceDateField.Value.ValueType == FieldValueType.Date)

                {

                    DateTime invoiceDate = new DateTime();

                    try

                    {

                        invoiceDate = invoiceDateField.Value.AsDate();

                    }

                    catch

                    {

                        string tmpDate = invoiceDateField.ValueData.Text;

                        tmpDate = tmpDate.Replace(" ", "");

                        tmpDate = Regex.Replace(tmpDate, "[年月⽉]", "/");

                        tmpDate = Regex.Replace(tmpDate, "[⽇日]", "");

                        _logger.LogDebug($"{tmpDate}");

                        invoiceDate = DateTime.Parse(tmpDate);

                    }

                    _logger.LogInformation($"Invoice Date: '{invoiceDate}', with confidence {invoiceDateField.Confidence}");

                }

            }

        }

    }

}

～省略～

using Microsoft.Extensions.DependencyInjection;

using Microsoft.Extensions.Hosting;

using FormRecognizer.Services;

namespace FormRecognizer

{

～省略～

        public void ConfigureServices(IServiceCollection services)

        {

            services.AddRazorPages();

            services.AddScoped<IRecognizer, Recognizer>();

        }

～省略～

using System;

using System.Collections.Generic;

using System.Linq;

using System.Threading.Tasks;

using Microsoft.AspNetCore.Mvc;

using Microsoft.AspNetCore.Mvc.RazorPages;

using Microsoft.Extensions.Logging;

using FormRecognizer.Services;

using System.ComponentModel.DataAnnotations;

using Microsoft.AspNetCore.Http;

namespace FormRecognizer.Pages

{

    public class IndexModel : PageModel

    {

        private readonly ILogger<IndexModel> _logger;

        private readonly IRecognizer _recoginzer;

        [BindProperty(SupportsGet = true)]

        public string Notice { get; set; }

        [BindProperty]

        public SingleFileUpload FileUpload { get; set; }

        public IndexModel(ILogger<IndexModel> logger, IRecognizer recognizer)

        {

            _logger = logger;

            _recoginzer = recognizer;

        }

        public void OnGet()

        {

        }

        public async Task<IActionResult> OnPostUploadAsync()

        {

            if (!ModelState.IsValid) return Page();

            Notice = $"{FileUpload.FormFile.FileName} を読み込みました";

            await _recoginzer.RecognizeFromFile(FileUpload.FormFile);

            return RedirectToPage("./Index", new { Notice });

        }

        public class SingleFileUpload

        {

            [Required]

            [Display(Name = "請求書ファイル")]

            public IFormFile FormFile { get; set; }

        }

    }

}

@page

@model IndexModel

@{

    ViewData["Title"] = "Form Recognizer";

}

<div class="row">

    <div class="col-1"></div>

    <div class="col-3">

        <form enctype="multipart/form-data" method="post">

            <label>請求書ファイル</label>

            <input asp-for="FileUpload.FormFile" type="file">

            <span asp-validation-for="FileUpload.FormFile"></span>

            <button type="submit" asp-page-handler="upload" class="btn btn-primary btn-block mt-1">Upload</button>

        </form>

    </div>

    <div class="col-7">

        <p class="text-danger">@Model.Notice</p>

    </div>

    <div class="col-1"></div>

</div>

@section Scripts{

    @{await Html.RenderPartialAsync("_ValidationScriptsPartial");}

}

$ dotnet run