C#反射(Reflection)的应用
反射(reflection)是c#里很重要的一个特性，其它 语言也有这个特性，比如java。反射这个特性是很实用的，这个到底有多实用呢，我也说不清，如果使用过struts, hibernate, spring等等这些框架的话，便会知道反射这个特性是多么的强大了。好像我列出的都是java的框架，.net的框架我不了解，有没有我都不知道。但在我接触过的那些框架中，没有一个框架是不使用反射的，没有反射特性的语言除外。
这是model程序集中的一个类：
code
using system;
using system.collections.generic;
using system.text;
namespace model
{
public class userinfo
{
private int userid;
public int userid
{
get { return userid; }
set { userid = value; }
}
private string username;
public string username
{
get { return username; }
set { username = value; }
}
public void show()
{
console.writeline("userid:" + userid + ", username:" + username);
}
}
}
这是反射的操作：
code
using system;
using system.collections.generic;
using system.text;
using system.reflection;
namespace objectloader
{
public class showobject
{
//加载程序集
private assembly assembly = assembly.load("model");
/// <summary>
/// 实例化类，要包含它的命名空间
/// </summary>
/// <param name="objname">类名</param>
/// <returns></returns>
public object loadobject(string objname)
{
return assembly.createinstance("model." + objname);
}
/// <summary>
/// 返回所有的公共属性
/// </summary>
/// <param name="obj"></param>
/// <returns></returns>
public propertyinfo[] getpropertys(object obj)
{
type type = obj.gettype();
propertyinfo[] infos = type.getproperties();
return infos;
}
/// <summary>
/// 设置实例的指定属性值
/// </summary>
/// <param name="obj">实例</param>
/// <param name="property">属性名</param>
/// <param name="value">值</param>
public void setpropertyvalue(object obj, string property, object value)
{
type type = obj.gettype();
propertyinfo info = type.getproperty(property);
if (info != null)
{
info.setvalue(obj, value, null);
}
}
/// <summary>
/// 返回指定属性值
/// </summary>
/// <param name="obj">实例</param>
/// <param name="property">属性名</param>
/// <returns></returns>
public object getpropertyvalue(object obj, string property)
{
type type = obj.gettype();
propertyinfo info = type.getproperty(property);
if (info == null)
{
return null;
}
return info.getvalue(obj, null);
}
/// <summary>
/// 执行实例的指定方法
/// </summary>
/// <param name="obj"></param>
/// <param name="methodname">方法名</param>
public void executemethod(object obj, string methodname)
{
type type = obj.gettype();
methodinfo info = type.getmethod(methodname);
if (info != null)
{
info.invoke(obj, null);
}
}
}
}
下面是测试类：
code
using system;
using system.collections.generic;
using system.text;
using system.reflection;
using model;
using objectloader;
namespace reflectiontest
{
class program
{
static void main(string[] args)
{
showobject showobj = new showobject();
object obj = showobj.loadobject("userinfo");
console.writeline("实例名：" + obj.gettype().fullname);
console.writeline("实例的所有公共属性：");
propertyinfo[] pinfos = showobj.getpropertys(obj);
foreach (propertyinfo info in pinfos)
{
console.writeline(info.gettype() + ":" + info.name);
}
showobj.setpropertyvalue(obj, "userid", 1);
showobj.setpropertyvalue(obj, "username", "admin");
console.writeline("设置属性值后的值");
console.writeline("userid:" + showobj.getpropertyvalue(obj,"userid"));
console.writeline("username:" + showobj.getpropertyvalue(obj, "username"));
console.writeline("执行实例的方法：");
showobj.executemethod(obj, "show");
}
}
}
code:
using system;
using system.collections;
using system.text;
using system.data;
using objectloader;
namespace datatableaop
{
public class objectlist
{
/// <summary>
/// 将datatable转换成arraylist
/// </summary>
/// <param name="datatable"></param>
/// <param name="name">类名</param>
/// <returns></returns>
public static arraylist getobjectlist(datatable datatable, string name)
{
showobject show = new showobject();
datarowcollection rows = datatable.rows;
arraylist list = new arraylist();
foreach (datarow row in rows)
{
//使用反射生成新的实例
object obj = show.loadobject("username");
foreach (datacolumn column in datatable.columns)
{
//根据字段名设置属性值
show.setpropertyvalue(obj, column.columnname, row[column.columnname]);
}
list.add(obj);
}
return list;
}
}
}
