c#獲取每季度的起始/結束日期

選擇季度

`//計算每季度的起始/結束日期

    protected void GetQyarter(out DateTime dt_Start_Date, out DateTime dt_End_Date)
    {
        int[] n_Months = new int[5] { 1, 4, 7, 10, 1 };
        int n_NowQuarter = 0;
        for (int i = 0; i < n_Months.Length; i++)
        {
            if (DateTime.Now.Month <= n_Months[i])
            {
                n_NowQuarter = i + 1;
                break;
            }
        }
        n_NowQuarter = 0;
		//判斷是否選擇季度Radio,以及選擇的是哪個Radio
        if (!int.TryParse(RadioButtonList1.SelectedValue,out n_NowQuarter))
        {
            dt_Start_Date = DateTime.Now;
            dt_End_Date = DateTime.Now.AddDays(1);
            return;
        }
        //起始日
        dt_Start_Date = DateTime.Parse(DateTime.Now.Year + "-" + n_Months[n_NowQuarter - 1].ToString("##"));
        //結束日
        dt_End_Date = DateTime.Parse((n_NowQuarter == 4 ? DateTime.Now.Year + 1 : DateTime.Now.Year) + "-" + n_Months[n_NowQuarter].ToString("##")).AddDays(-1);
        
    }`
	
	//在其它位置使用時調用上面的方法
	DateTime dt_StartDate;
        DateTime dt_EndDate;
        GetQyarter(out dt_StartDate,out dt_EndDate);