using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Text;
using System.Reflection;
namespace ConsoleApplication6
{
/// <summary>
/// AttributeTargets.Class可以对类应用属性
/// Inherited能否由派生类或重写成员继承
/// AllowMultiple能否为一个程序元素指定多个指示属性实例
/// 也就是说AllowMultiple=false 对于一个类型,该特性只能用一次
/// 若一个Class类型前面出现多个TableAttribute,则会出现编译错误
/// </summary>
[AttributeUsage(AttributeTargets.Class,Inherited=true,AllowMultiple=false)]
public class TableAttribute : Attribute
{
private string _tableName;
public TableAttribute()
{
}
public TableAttribute(string tableName)
{
this._tableName = tableName;
}
public string TableName
{
get
{
return this._tableName;
}
set
{
this._tableName = value;
}
}
}
/// <summary>
/// 列特性
/// AttributeTargets.Property可以对属性应用特性
/// </summary>
[AttributeUsage(AttributeTargets.Property,Inherited=false,AllowMultiple=false)]
public class ColumAttribute : Attribute
{
private string _columName;
private DbType _dbType;
public ColumAttribute()
{
}
public ColumAttribute(string columName)
{
this._columName = columName;
}
public ColumAttribute(string columName, DbType dbType)
{
this._columName = columName;
this._dbType = dbType;
}
public string ColumName
{
get
{
return this._columName;
}
set
{
this._columName = value;
}
}
public DbType DbTypeAttr
{
get
{
return this._dbType;
}
set
{
_dbType = value;
}
}
}
[Table("User")]
public class User
{
[Colum("userId",DbType.Int32)]
public int UserId { get; set; }
[Colum("userName", DbType.String)]
public string UserName { get; set; }
}
class Program
{
static void Main(string[] args)
{
User u = new User();
u.UserId = 6;
u.UserName = "allen";
Type myObjType = u.GetType();
Dictionary<string,string> columName = new Dictionary<string,string>();
//获取自定义特性
object temp = myObjType.GetCustomAttributes(typeof(TableAttribute),false).First();
TableAttribute myAttr = temp as TableAttribute;
Console.WriteLine("表名:{0}", myAttr.TableName);
Console.WriteLine("列的名称和值:");
foreach (PropertyInfo pi in myObjType.GetProperties())
{
object attr = pi.GetCustomAttributes(false).First();
ColumAttribute cattr = attr as ColumAttribute;
Console.WriteLine("{0}:{1}",cattr.ColumName,pi.GetValue(u,null));
}
Console.ReadKey();
}
}
}