关于.NET List<T>泛型方法

1、引入using System.Reflection;

/// <summary>
/// 用提供的函数，执行SQL命令，返回一个从指定连接的数据库记录集
/// </summary>
/// <param name="connecttionString">一个现有的数据库连接</param>
/// <param name="cmdText">SqlCommand命令类型</param>
/// <param name="cmdText">存储过程的名字或者 T-SQL 语句</param>
/// <returns>返回一个表(List<T>)表示查询得到的数据集</returns>
public static List<T> GetList<T>(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] cmdParms) where T : new()
{
DataTable table = GetDataTable(connectionString, cmdType, cmdText, null);
List<T> list = new List<T>();
T t = default(T);
PropertyInfo[] propertypes = null;
string tempName = string.Empty;
foreach (DataRow row in table.Rows)
{
t = Activator.CreateInstance<T>();
propertypes = t.GetType().GetProperties();
foreach (PropertyInfo pro in propertypes)
{
tempName = pro.Name;
if (table.Columns.Contains(tempName))
{
var value = row[tempName];
if (!value.ToString().Equals(""))
{
pro.SetValue(t, value);
}
}
}
list.Add(t);
}
return list.Count == 0 ? null : list;
}

/// <summary>
/// 用提供的函数，执行SQL命令，返回一个从指定连接的数据库记录集
/// </summary>
/// <param name="cmdType">cmdType CommandType</param>
/// <param name="cmdText">cmdText Sql语句</param>
/// <param name="cmdParms">cmdParms Sql参数数组</param>
/// <returns>Datatable 数据集</returns>
public static DataTable GetDataTable(string connectionString, CommandType cmdType, string cmdText, params SqlParameter[] cmdParms)
{
SqlCommand cmd = new SqlCommand();
DataSet ds = new DataSet();
using (SqlConnection conn = new SqlConnection(connectionString))
{
PrepareCommand(null, cmd, conn, cmdType, cmdText, cmdParms);
SqlDataAdapter adapter = new SqlDataAdapter();
adapter.SelectCommand = cmd;
adapter.Fill(ds, "table");
}
return ds.Tables["table"];
}