private async void button1_Click(object sender, EventArgs e)
{
    this.button1.Enabled = false;   // 処理中にボタンを押されないようにボタンを無効にする
    this.label1.BackColor = Color.Red;　// ラベル背景色変更
    this.label1.Text = "実行中";
    this.progressBar1.Style = ProgressBarStyle.Marquee; // プログレスバーをマーキー表示に
 
　　// 重い処理は別タスクで非同期実行
    await Task.Run(() =>
    {
        //ちょっと時間のかかる処理
        Thread.Sleep(10000);
     });
 
    this.progressBar1.Style = ProgressBarStyle.Continuous;　// プログレスバーを止める
    this.label1.BackColor = SystemColors.Control; // ラベル背景色を元に戻す
    this.label1.Text = string.Empty;
    this.button1.Enabled = true;  // ボタンを有効に戻す
}    

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