C# 字符串转换成日期，两个日期值比较大小，求两个日期相差天数

1、字符串转换成日期

如ruzhuDate = "2015-12-16"

         DateTime ruzhuDate = Convert.ToDateTime(dgv2.Rows[i].Cells["ruzhuDate"].Value.ToString());

         string banchuDate = dgv2.Rows[i].Cells["banchuDate"].Value.ToString() == string.Empty ? "" :Convert.ToString(dgv2.Rows[i].Cells["banchuDate"].Value);

         DateTime date =  Convert.ToDateTime(banchuDate)

2、两个日期值比较大小

如qsrq = "2015-12-30"

DateTime.Compare(ruzhuDate, qsrq) < 0

DateTime.Compare(t1,t2),方法获取一个数字,果之小于0,则t1<t2,大于0,则t1>t2, 等于0,则t1=t2

2、两个日期相差天数

如qsrq = "2015-11-25"

    jsrq = "2015-12-24"

    System.TimeSpan diff = jsrq.Subtract(qsrq);
    dgv2.Rows[i].Cells["dayQty"].Value = diff.Days.ToString();

C#中计算2个时间之间的差(可以计算到时分秒);

　　参考代码如下：

label1.Text = "2012-1-1 15:36:05";
label2.Text = "2012-2-1 20:16:35";
DateTime d1 =new DateTime(2012,1,1,15,36,05);
DateTime d2 =new DateTime(2012,2,1,20,16,35);

TimeSpan d3 = d2.Subtract(d1);

label3.Text = "相差:"
+d3.Days.ToString()+"天"
+d3.Hours.ToString()+"小时"
+d3.Minutes.ToString()+"分钟"
+d3.Seconds.ToString()+"秒";