C#实现DataTable按天分组并计数

使用LINQ语句进行查询

var value = from data in dataSet.Tables[0].AsEnumerable()
		//where before <= data.Field<DateTime>("alarmTime") &&
		//      data.Field<DateTime>("alarmTime") <= now
		group data by data.Field<DateTime>("alarmTime").ToString("yyyy-MM-dd")
		into r
		select new
		{
		    count = r.Count()
		};

访问数据

foreach (var v in value)
{
		Console.WriteLine(v.vount);
 }