今天有点时间，来说说如何设计的实体类更加合理，灵活，规范．
首先，那要和真实数据表一一对应，必要的话，可以对类型抽象化，可以引入枚举，泛型列表等类型；其次，对实体要集成它的数据有效性的验证功能；再次，为了数据操作方便，有必要去引入数据表字段的列举集合；综上所述，我们来设计一个用户表实体;
本例中的知识点为：部分类，接口规范，Flag属性的枚举，迭代器等
/// <summary>
/// 数据实体统一接口
/// </summary>
public interface IDataEntity
{
}
/// <summary>
/// 用户实体
/// </summary>
partial class UserBase : IDataEntity
{
public string UserName { get; set; }
public int Age { get; set; }
}
/// <summary>
/// 实体验证类
/// </summary>
public class RuleViolation
{
/// <summary>
/// 错误属性
/// </summary>
public string ErrProperty { get; private set; }
/// <summary>
/// 错误信息
/// </summary>
public string ErrMessage { get; private set; }
public RuleViolation(string errProperty, string errMessage)
{
this.ErrProperty = errProperty;
this.ErrMessage = errMessage;
}
public RuleViolation(string errMessage)
: this(errMessage, null)
{
}
}
/// <summary>
/// 实体验证统一接口
/// </summary>
public interface IEntity
{
/// <summary>
/// 验证是否通过
/// </summary>
bool IsValid { get; }
/// <summary>
/// 以迭代的形式返回验证列表
/// </summary>
/// <returns></returns>
IEnumerable<RuleViolation> GetRuleViolations();
}
/// <summary>
/// 用户实体验证
/// </summary>
public partial class UserBase : IEntity
{
#region IEntity Members
public bool IsValid
{
get { return this.GetRuleViolations().Count() == 0; }
}
public IEnumerable<RuleViolation> GetRuleViolations()
{
if (string.IsNullOrEmpty(this.UserName))
yield return new RuleViolation("UserName", "用户名为能为空");
if (this.Age == 0)
yield return new RuleViolation("Age", "没有年龄为０的数据,至少为１");
}
#endregion
}
/// <summary>
/// 表字段列举
/// </summary>
[Flags]
public enum UserBaseColumns
{
UserName = 1,
Age = 2,
}
