Question

C#点击button获取上一周

C# 点击button1按钮，获取上一周的日期，在点击按钮，再获取上一周的日期，依次循环。。。。。
点击button2按钮，获取下一周的日期，在点击按钮，再获取下一周的日期，依次循环。。。。。

Answer 1

DateTime dtNow;
        private void Form1_Load(object sender, EventArgs e)
        {
            label2.Text = DateTime.Now.ToString("yyyy-MM-dd");
            dtNow = DateTime.Now;
        }
        private void bt_preWeek_Click(object sender, EventArgs e)
        {
            showDays(false);//上一周
        }
        private void bt_nextWeek_Click(object sender, EventArgs e)
        {
            showDays(true);//下一周
        }
        /// <summary>
        /// 显示一周以内的日期
        /// </summary>
        /// <param name="isNext">是否为下一周，否则为上一周</param>
        void showDays(bool isNext)
        {
            textBox1.Text = "";
            int k = isNext ? 1 : -1;
            DateTime d1 = dtNow.AddDays(k*7);
            while (d1.DayOfWeek != DayOfWeek.Sunday)
            {
                d1 = d1.AddDays(k);
            }
            for (int i = 0; i < 7; i++)
            {
                textBox1.AppendText(d1.AddDays(i).ToString("yyyy-MM-dd") + Environment.NewLine);
            }
            dtNow = d1;//起始日期
        }