/// <summary>
/// 字符串
/// </summary>
/// <param name="propNames"></param>
/// <returns></returns>
public String ToString(params String[] propNames)
{
if (propNames == null || propNames.Length <= 0)
{
propNames = PDC.ConvertAll(x => x.Name).ToArray();
}
StringBuilder str = new StringBuilder();
return(propNames.ToList().ConvertAll(x => this.Get <String>(x)).Aggregate((x, y) => x + "," + y));
}