反射小应用之DataTable和List<T>互操作

public static class DataTableEntityInteroperate
{
    /// <summary>
    /// List<T> to DataTable
    /// </summary>
    /// <typeparam name="T">Entity</typeparam>
    /// <param name="entities">Entities</param>
    /// <returns>DataTable</returns>
    internal static DataTable ToDataTable<T>(this List<T> entities) where T : class,new()
    {
        //IsNull return
        if (null == entities || entities.Count == 0)
            return null;
        //Initial Columns
        DataTable dt = new DataTable();
        PropertyInfo[] pArray = typeof(T).GetProperties();
        Array.ForEach<PropertyInfo>(pArray, p =>
        {
            dt.Columns.Add(p.Name);
        });
        //Initial Rows
        DataRow dr = dt.NewRow();
        entities.ForEach(t =>
        {
            int i = 0;
            Array.ForEach<PropertyInfo>(pArray, p =>
            {
                if (dt.Columns.Contains(p.Name))
                    dr[i] = p.GetValue(t); //Assigned to each column
            });
            i++;
        });
        return dt;
    }

    /// <summary>
    /// DataTable to Entities
    /// </summary>
    /// <typeparam name="T">Entity</typeparam>
    /// <param name="dt">DataTable</param>
    /// <returns>List<T</returns>
    internal static List<T> ToEntities<T>(this DataTable dt)/*必须来在于数据库来自于文件可能存在问题*/ where T : class,new()
    {
        //IsNullable
        if (null == dt || dt.Rows.Count == 0)
            return null;
        //Initial Entities
        List<T> entities = new List<T>();
        foreach (DataRow row in dt.Rows)
        {
            PropertyInfo[] pArray = typeof(T).GetProperties();
            T entity = new T();
            Array.ForEach<PropertyInfo>(pArray, p =>
                {
                    p.SetValue(entity, row[p.Name], null);
                });
            entities.Add(entity);
        }
        return entities;
    }
}