使用反射訪問: 自定義屬性的信息和對其進行操作的方法。
一、實例1
1、代碼:
如:System.Attribute[] attrs=System.Attribute.GetCustomAttributes(typeof(FirstClass));
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
PrintAuthorInfo(typeof(FirstClass));
PrintAuthorInfo(typeof(SecondClass));
PrintAuthorInfo(typeof(ThirdClass));
Console.ReadKey();
}
private static void PrintAuthorInfo(System.Type t)
{
System.Console.WriteLine("\n類型的 System.Type 對象是:{0}", t);
System.Attribute[] attrs = System.Attribute.GetCustomAttributes(t); //反射獲得用戶自定義屬性
foreach (System.Attribute attr in attrs)
{
if (attr is Author)
{
Author a = (Author)attr;
System.Console.WriteLine(" 名稱:{0}, 版本: {1:f}", a.GetName(), a.version);
}
}
}
}
[System.AttributeUsage(System.AttributeTargets.Class |
System.AttributeTargets.Struct,
AllowMultiple = true)
]//自定義特性類(應用特性的程序元素(是類或結構),程序元素可以指定多個特性)
public class Author : System.Attribute
{
string name;
public double version;
public Author(string name)
{
this.name = name;
version = 1.0; // Default value
}
public string GetName()
{
return name;
}
}
[Author("H. Ackerman")]
public class FirstClass
{
// ...
}
// No Author attribute
public class SecondClass
{
// ...
}
[Author("H. Ackerman"), Author("M. Knott", version = 2.0)]
public class ThirdClass
{
//程序元素可以指定多個特性
}
}
2、效果:
二、實例2
1、代碼
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Linq.Expressions;
using System.Collections.Specialized;
using System.Reflection;
using System.Data.Linq.Mapping;
namespace ConsoleApplication1
{
class Program
{
static void Main(string[] args)
{
PropertyInfo[] propertys = typeof(FirstClass).GetProperties();//返回FirstClass的所有公共屬性
if (propertys != null && propertys.Length > 0)
{
foreach (PropertyInfo p in propertys)
{
object[] objAttrs = p.GetCustomAttributes(typeof(ColumnAttribute), true);//獲取自定義特性
//GetCustomAttributes(要搜索的特性類型,是否搜索該成員的繼承鏈以查找這些特性)
if (objAttrs != null && objAttrs.Length > 0)
{
ColumnAttribute attr = objAttrs[0] as ColumnAttribute;
Console.WriteLine("自定義特性Name:"+p.Name+", 元數據:"+attr);
}
};
}
Console.ReadKey();
}
}
public class FirstClass
{
private int _newsid = 0;
/// <summary>
/// 主鍵
/// </summary>
[Column(Name = "NewsId", DbType = "int", IsPrimaryKey = true, CanBeNull = false, IsDbGenerated = true)]
public int NewsId
{
get
{
return this._newsid;
}
set
{
this._newsid = value;
}
}
private string _newsimage = string.Empty;
/// <summary>
/// 資訊標題圖片
/// </summary>
[Column(Name = "NewsImage", DbType = "varchar", IsPrimaryKey = false, CanBeNull = false, IsDbGenerated = false)]
public string NewsImage
{
get
{
return this._newsimage;
}
set
{
this._newsimage = value;
}
}
}
}
2、效果
其他:
FullName(獲得System.Type的完全限定名,包括命名空間)
三、實例3 (設置指定實例 屬性 的值)
FirstClass fClass = new FirstClass();
PropertyInfo pInstance = typeof(FirstClass).GetProperty("NewsId");//搜索具有指定名稱的公共屬性
pInstance.SetValue(fClass, 11, null);//設置指定實例 屬性 的值
Console.WriteLine("新聞ID:"+fClass.NewsId);
Console.WriteLine("新聞圖片:"+fClass.NewsImage);
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原文鏈接:https://blog.csdn.net/litao2/article/details/17633107