datatable 使用LAMBDA表达查询，过滤

DataTable dt = new DataTable();
DataColumn dc = new DataColumn("UserName", System.Type.GetType("System.String"));
DataColumn dc1 = new DataColumn("UserPwd", System.Type.GetType("System.String"));
dt.Columns.Add(dc);
dt.Columns.Add(dc1);
DataRow dr = dt.NewRow();
dr["UserName"] = "22";
dr["UserPwd"] = "33";
dt.Rows.Add(dr);

var rownumber = dt.AsEnumerable().Where<DataRow>(C=>C["UserName"].ToString()=="22");
int row = rownumber.Count<DataRow>();
foreach ( DataRow en in  rownumber)
{

Response.Write("User" + en["UserName"] + "pwd" + en["UserPwd"]);
}