textBox1.Text = dateTimePicker1.Value.ToString("yyyy-MM-dd HH:mm:ss");

            int[] arr = { 100, 20, 2, 4, 104, 1, 21, 101, 102, 201, 202 };
            var data = arr.Where(n => n % 2 == 0 && n > 100).OrderByDescending(n => n);
            foreach (var x in data) {
                Console.WriteLine(x);
            }
            Console.ReadKey();
 

輸出字符串格式化