今天是9.22。星期3，要求离上个月22号最近的星期3

Question

今天是9.22。星期3，要求离上个月22号最近的星期3怎么写代码，详细最好，思路也行

Answer 1

取得星期几
int i = Convert.ToInt32(DateTime.Now.DayOfWeek)
根据如果得到1.就是DateTime.Now.AddMonths(-1).AddDays(3-i);

Answer 2

            DateTime dt1 = Convert.ToDateTime(this.textBox1.Text);            //上个月的今天
            DateTime dt2 = dt1.AddMonths(-1);            if ((Int32)dt2.DayOfWeek - (Int32)dt1.DayOfWeek > 3)
            {
                MessageBox.Show(dt2.AddDays(-1-(Int32)dt1.DayOfWeek + (Int32)dt2.DayOfWeek).ToString());
            }
            else
            {
                MessageBox.Show(dt2.AddDays((Int32)dt1.DayOfWeek-(Int32)dt2.DayOfWeek ).ToString());            }

Answer 3

 DateTime dt = new DateTime(2010,9,22);
           Response.Write(String.Format("{0:yyyy-MM-dd}是星期{1}",dt,dt.DayOfWeek.ToString("D")));
           Response.Write("<br/>");
           dt = dt.AddMonths(-1);
           if (Convert.ToInt32(dt.DayOfWeek.ToString("D")) == 3)
           { Response.Write("上个月最近的星期三就是今天"); }
           else if (Convert.ToInt32(dt.DayOfWeek.ToString("D")) < 3)
           {
               Response.Write(String.Format("上个月最近的星期三是{0:yyyy-MM-dd}", dt.AddDays(3 - Convert.ToInt32(dt.DayOfWeek.ToString("D")))));
           }
           else
           {
               Response.Write(String.Format("上个月最近的星期三是{0:yyyy-MM-dd}", dt.AddDays(3 - Convert.ToInt32(dt.DayOfWeek.ToString("D")))));
           }
           Response.End();

Answer 4

楼主上个代码多写了一个判断，用下面这个：   DateTime dt = new DateTime(2010,9,22);
           Response.Write(String.Format("{0:yyyy-MM-dd}是星期{1}",dt,dt.DayOfWeek.ToString("D")));
           Response.Write("<br/>");
           dt = dt.AddMonths(-1);
           if (Convert.ToInt32(dt.DayOfWeek.ToString("D")) == 3)
           { Response.Write("上个月最近的星期三就是今天"); }
           else
           {
               Response.Write(String.Format("上个月最近的星期三是{0:yyyy-MM-dd}", dt.AddDays(3 - Convert.ToInt32(dt.DayOfWeek.ToString("D")))));
           }
           Response.End();