DataTable字符串類型的數字，按照數字類型排序

protected void Page_Load(object sender, EventArgs e)
    {
        DataTable dt = new DataTable();
        dt.Columns.Add("Name");
        dt.Columns.Add("Age");//因為是字符串，所以排序不對
        dt.Rows.Add("小明", "21");
        dt.Rows.Add("小張", "10");
        dt.Rows.Add("小紅", "9");
        dt.Rows.Add("小偉", "7");
        dt.Rows.Add("小美", "3");
        dt.DefaultView.Sort = "Age ASC";
        dt = dt.DefaultView.ToTable();

        foreach (DataRow s in dt.Rows)
        {
            Response.Write(s["Age"].ToString() + "--" + s["Name"].ToString() + "<br/>");
        }
        Response.Write("------------------1----------------<br/>");

 
        #region 方法1:將年齡補齊為2位，然后再進行排序，但是實際不應該有0(僅作參考)
        for (int i = 0; i < dt.Rows.Count; i++)
        {
            dt.Rows[i]["Age"] = dt.Rows[i]["Age"].ToString().PadLeft(2, '0');
        }
        dt.DefaultView.Sort = "Age ASC";

        dt = dt.DefaultView.ToTable();

        foreach (DataRow s in dt.Rows)
        {
            Response.Write(s["Age"].ToString() + "--" + s["Name"].ToString() + "<br/>");
        }
        #endregion

        Response.Write("------------------2----------------<br/>");

        #region 方法2:創建新的DataTable，將Age類型變更為int類型
        DataTable dtNew = dt.Clone();
        dtNew.Columns["Age"].DataType = typeof(int);//指定Age為Int類型
        foreach (DataRow s in dt.Rows)
        {
            dtNew.ImportRow(s);//導入舊數據
        }

        dtNew.DefaultView.Sort = "Age ASC";
        dtNew = dtNew.DefaultView.ToTable();

        foreach (DataRow s in dtNew.Rows)
        {
            Response.Write(s["Age"].ToString() + "--" + s["Name"].ToString() + "<br/>");
        }
        #endregion

        Response.Write("-----------------3-----------------<br/>");

        #region 方法3:添加一列，主要用於排序
        dt.Columns.Add("AgeLength", typeof(int), "len(Age)");//添加該列時，DataTable列數據即生成

        dt.DefaultView.Sort = "AgeLength,Age ASC";
        dt = dt.DefaultView.ToTable();

        foreach (DataRow s in dt.Rows)
        {
            Response.Write(s["Age"].ToString() + "--" + s["Name"].ToString() + "<br/>");
        }
        #endregion

        Response.Write("-----------------4-----------------<br/>");

        #region 方法4:運用LinQ,將DataTable轉換為集合，再調用集合自帶的排序方法進行排序
        foreach (DataRow s in dt.Rows.Cast<DataRow>().OrderBy(r => int.Parse(r["Age"].ToString())))
        {
            Response.Write(s["Age"].ToString() + "--" + s["Name"].ToString() + "<br/>");
        }
        #endregion
    }