protected void Page_Load(object sender, EventArgs e)     {         DataTable dt = new DataTable();         dt.Columns.Add("Name");         dt.Columns.Add("Age");//因为是字符串，所以排序不对         dt.Rows.Add("小明", "21");         dt.Rows.Add("小张", "10");         dt.Rows.Add("小红", "9");         dt.Rows.Add("小伟", "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:将年龄补齐为2位，然后再进行排序，但是实际不应该有0(仅作参考)         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:创建新的DataTable，将Age类型变更为int类型         DataTable dtNew = dt.Clone();         dtNew.Columns["Age"].DataType = typeof(int);//指定Age为Int类型         foreach (DataRow s in dt.Rows)         {             dtNew.ImportRow(s);//导入旧数据         }         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，主要用于排序         dt.Columns.Add("AgeLength", typeof(int), "len(Age)");//添加该列时，DataTable列数据即生成         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:运用LinQ,将DataTable转换为集合，再调用集合自带的排序方法进行排序         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     }