小学校1年生で習う繰上りありの足し算を延々と音声で解答するC#デスクトップアプリ

Form1.cs

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Speech.Recognition;

namespace WindowsFormsApplication3
{
    public partial class Form1 : Form
    {
        private SpeechRecognitionEngine recognizer;
        private int[] operand1 = new int[5];
        private int[] operand2 = new int[5];
        private Random r;

        public Form1()
        {
            InitializeComponent();

            // 問題データの初期化
            for (int i = 0; i < operand1.Length; i++)
            {
                operand1[i] = i + 5;
                operand2[i] = i + 5;
            }

            // 乱数の初期化
            r = new System.Random();
        }

        private async void button1_Click(object sender, EventArgs e)
        {
            try
            {
                int op1 = operand1[r.Next(operand1.Length)];
                int op2 = operand2[r.Next(operand2.Length)];
                int answer = op1 + op2;
                string question = op1 + " + " + op2 + " = ";
                button1.Text = question;

                // 音声認識の初期化
                recognizer = new SpeechRecognitionEngine();
                string[] strArray = new string[18];
                for (int i = 1; i <= strArray.Length; i++)
                {
                    strArray[i - 1] = i.ToString();
                }
                Choices colorChoice = new Choices(strArray);
                Grammar dictationGrammar = new Grammar(colorChoice);
                recognizer.LoadGrammar(dictationGrammar);
                recognizer.SetInputToDefaultAudioDevice();
                RecognitionResult result = recognizer.Recognize();
                if(result != null) { 
                    if(answer.ToString().Equals(result.Text)) {
                        button1.Text = "正解! " + question + answer;
                    } else {
                        button1.Text = result.Text + "は、ちがうよ..." + question + answer;
                    }
                } else {
                    button1.Text = "聞き取れなかったよ...";
                }

                await Task.Delay(1000);
                button1_Click(sender, e);
            }
            catch (InvalidOperationException exception)
            {
                button1.Text = String.Format("Could not recognize input from default aduio device. Is a microphone or sound card available?\r\n{0} - {1}.", exception.Source, exception.Message);
            }
            finally
            {
                recognizer.UnloadAllGrammars();
            }
        }
    }
}