Linq内での変数に関して

using BenchmarkDotNet.Attributes;
using BenchmarkDotNet.Running;
using System;
using System.Text;
using System.Threading;
using System.Windows.Forms;


[ShortRunJob]
[MemoryDiagnoser(false)]
public class SimpleBenchnark
{
    private Form1 _frm = new Form1();
    private Thread _uiThread;
    const int N = 10000;

    [GlobalSetup]
    public void Setup()
    {
        _uiThread = new Thread(new ThreadStart(() => {
                Application.EnableVisualStyles();
                Application.SetCompatibleTextRenderingDefault(false);
                Application.Run(_frm);
            }));

        _uiThread.SetApartmentState(ApartmentState.STA);
        _uiThread.Start();
    }

    [Benchmark]
    public string GetTextOnce()
    {
        var result = string.Empty;
        _frm.Invoke(new Action(() =>
        {
            result = _frm.textBox1.Text;
        }));

        return result;
    }

    [Benchmark]
    public string GetTextN()
    {
        var result = string.Empty;
        _frm.Invoke(new Action(() =>
        {
            var text = _frm.textBox1.Text;
            var buf = new StringBuilder(N * 10);
            for (int i = 0; i < N; i++)
            {
                buf.Append(text);
            }
            result = buf.ToString();
        }));
        return result;
    }

    [Benchmark]
    public string GetTextPropertyN()
    {
        var result = string.Empty;
        _frm.Invoke(new Action(() =>
        {
            var buf = new StringBuilder(N * 10);
            for (int i = 0; i < N; i++)
            {
                buf.Append(_frm.textBox1.Text);
            }
            result = buf.ToString();
        }));
        return result;
    }

    public static void Run() => BenchmarkRunner.Run<SimpleBenchnark>();
}

internal static class Program
{
    [STAThread]
    static void Main()
    {
        SimpleBenchnark.Run();

        //Application.EnableVisualStyles();
        //Application.SetCompatibleTextRenderingDefault(false);
        //Application.Run(new Form1());
    }
}

        private void button1_Click(object sender, EventArgs e)
        {
            Stopwatch stopWatch = new Stopwatch();
            stopWatch.Start();
            string time = "";

            var hensu = this.textBox1.Text;
            var hensu2 = this.textBox2.Text;
            var result2 = this.table.AsEnumerable()
                          .Where(s => s[0].ToString() == $"{hensu}")
                          .Where(s => s[1].ToString() == $"{hensu2}");

            //var result1 = this.table.AsEnumerable()
            //              .Where(s => s[0].ToString() == this.textBox1.Text)
            //              .Where(s => s[1].ToString() == this.textBox2.Text);

            time = stopWatch.Elapsed.ToString();
            stopWatch.Reset();
            stopWatch.Start();

            var result1 = this.table.AsEnumerable()
                          .Where(s => s[0].ToString() == this.textBox1.Text)
                          .Where(s => s[1].ToString() == this.textBox2.Text);

            //var hensu = this.textBox1.Text;
            //var hensu2 = this.textBox2.Text;
            //var result2 = this.table.AsEnumerable()
            //              .Where(s => s[0].ToString() == $"{hensu}")
            //              .Where(s => s[1].ToString() == $"{hensu2}");

            time += " / " + stopWatch.Elapsed.ToString();

            this.label1.Text = time;
        }

// 1.TextBox1.Textの値が変更したときにイベント発火
private async void TxtYearMonth_TextChanged(object sender, EventArgs e)
{
    // 入力文字列の検証などの非同期処理

　　// 2.親のフォームからDataSetを取得し、イベントを発火
    DataSourceChangedEvent?.Invoke(this, null);
}

// 3.DataSourceChangedEventにGetDataSetEventをdelegateしています
DataSourceChangedEvent += GetDataSetEvent;

// 4.GetDataSetEventの実行
private async void GetDataSetEvent()
{
    await Task.WhenAll(SampleMethod1Async(),SampleMethod2Async(),
                       SampleMethod3Async())
} 

private async Task SampleMethod1Async()
{
　　await Task.Run(()=>{
　　    // 5.Tableから一意のデータを取得（データは5000～10000件程度）
        var result = _dataSet.Tables["Table1"].AsEnumerable()
                                              .Where(s => s[0].ToString() == TextBox.Text);
                                              .Where(s => s[1].ToString() == TextBox2.Text);
    // 取得した一意のデータを画面に反映
　　// 略
});
}

// SampleMethod2Async SampleMethod3AsyncはSampleMethod1Asyncとほぼ同じ処理（取得するテーブルが異なるだけ）

var result = _dataSet.Tables["Table1"].AsEnumerable()
                                      .Where(s => s[0].ToString() == TextBox.Text);
                                      .Where(s => s[1].ToString() == TextBox2.Text);

    private int _ReadMyName;
    private int _ReadMyDescription;
    private int _SearchNo = 9999;

    private string MyName
    {
        get
        {
            _ReadMyName++;
            return "name" + _SearchNo;
        }
    }

    private string MyDescription
    {
        get
        {
            _ReadMyDescription++;
            return "description" + _SearchNo;
        }
    }

    private void button1_Click(object sender, EventArgs e)
    {
        textBoxLog.Clear();
        Stopwatch stopWatch = new Stopwatch();
        stopWatch.Start();
        var result1 = this.table.AsEnumerable()
                      .Where(s => s[0].ToString() == this.MyName)
                      .Where(s => s[1].ToString() == this.MyDescription);

        stopWatch.Stop();
        textBoxLog.AppendText("(ReadProperty)\r\n");
        textBoxLog.AppendText($"Elapsed:{stopWatch.Elapsed}\r\n");
        textBoxLog.AppendText($"ReadMyName:{_ReadMyName}\r\n");
        textBoxLog.AppendText($"ReadMyDescription:{_ReadMyDescription}\r\n");

        stopWatch.Reset();
        stopWatch.Start();
        var hensu = this.MyName;
        var hensu2 = this.MyDescription;
        var result2 = this.table.AsEnumerable()
                      .Where(s => s[0].ToString() == $"{hensu}")
                      .Where(s => s[1].ToString() == $"{hensu2}");

        stopWatch.Stop();
        textBoxLog.AppendText("(ReadLocal)\r\n");
        textBoxLog.AppendText($"Elapsed:{stopWatch.Elapsed}\r\n");
        textBoxLog.AppendText($"ReadMyName:{_ReadMyName}\r\n");
        textBoxLog.AppendText($"ReadMyDescription:{_ReadMyDescription}\r\n");
    }