如何将日期中年月日拆分

从数据库中读取日期，有时数据库中存放的日期格式不一致，所以可以把日期格式先统一一下，然后根据需要读取年月日，代码如下：

//首先从数据库中读取onlinetime数据
string onlinetime = ds.Tables[0].Rows[i]["onlinetime"].ToString();

//将数据库中的日期转换成日期形式，再转换成字符串
onlinetime = Convert.ToDateTime(onlinetime).ToString("yyyy年MM月dd HH:mm:ss");

//截取 月 和 日 字符串
string month = onlinetime.Substring(5, 2);
string day = onlinetime.Substring(8, 2);

//调用下面的getMonthEng()方法
month = getMonthEng(int.Parse(month));

把月份转化为英文，代码如下：

private string getMonthEng( int month) 
    {
        string str = "";

        switch (month)
        {
            case 1:
                str = "Jan";
                break;
            case 2:
                str = "Feb";
                break;
            case 3:
                str = "Mat";
                break;
            case 4:
                str = "Apr";
                break;
            case 5:
                str = "May";
                break;
            case 6:
                str = "Jun";
                break;
            case 7:
                str = "Jul";
                break;
            case 8:
                str = "Aug";
                break;
            case 9:
                str = "Seb";
                break;
            case 0:
                str = "Oct";
                break;
            case 11:
                str = "Nov";
                break;
            case 12:
                str = "Dec";
                break;
            default:
                str = "Err";
                break;
        }
        return str;

    }