C# 获取从1月至12月的月初时间和月末时间

public IActionResult GetMonthData()
{
var dataList = new List<object>();

var currentMonth = DateTime.Now.Month;                       //获取当月
var currentDay = DateTime.Now.Day;                              //...........天
var currentHour = DateTime.Now.Hour;                           //...........时
var currentMinute = DateTime.Now.Minute;                     //...........分
var currentMillisecond = DateTime.Now.Millisecond;       /............秒

for (int i = 1; i <= 12; i++)
{
var monthStart = DateTime.Now.AddMonths(i - currentMonth).AddDays(1-currentDay).AddHours(-currentHour)
.AddMinutes(-currentMinute).AddMilliseconds(-currentMillisecond);

var monthEnd = DateTime.Now.AddMonths(i - currentMonth+1).AddDays(1 - currentDay-1).AddHours(-currentHour)
.AddMinutes(-currentMinute).AddMilliseconds(-currentMillisecond);

dataList.Add(new monthStart=monthStart,monthEnd = monthEnd });
}

return Json(dataList); ;
}