C#反射机制 (转载)

转载:原文出处 

    http://www.cnblogs.com/binfire/archive/2013/01/17/2864887.html

一：反射的定义

　　审查元数据并收集关于它的类型信息的能力。元数据（编译以后的最基本数据单元）就是一大堆的表，当编译程序集或者模块时，编译器会创建一个类定义表，一个字段定义表，和一个方法定义表等。

　　System.reflection命名空间包含的几个类，允许你反射（解析）这些元数据表的代码

　　System.Reflection.Assembly 　　System.Reflection.MemberInfo 　　System.Reflection.EventInfo 　　System.Reflection.FieldInfo 　　System.Reflection.MethodBase 　　System.Reflection.ConstructorInfo 　　System.Reflection.MethodInfo 　　System.Reflection.PropertyInfo 　　System.Type

　　层次模型：

　　

二：获取类型信息：　

 1         class MyClass
 2         {
 3             public string m;
 4             public void test() { }
 5             public int MyProperty { get; set; }
 6         }
 7
 8         //获取类型信息
 9         protected void Button1_Click(object sender, EventArgs e)
10         {
11             Type type = typeof(MyClass);
12             Response.Write("类型名:" + type.Name);
13             Response.Write("<br/>");
14             Response.Write("类全名：" + type.FullName);
15             Response.Write("<br/>");
16             Response.Write("命名空间名:" + type.Namespace);
17             Response.Write("<br/>");
18             Response.Write("程序集名：" + type.Assembly);
19             Response.Write("<br/>");
20             Response.Write("模块名:" + type.Module);
21             Response.Write("<br/>");
22             Response.Write("基类名：" + type.BaseType);
23             Response.Write("<br/>");
24             Response.Write("是否类：" + type.IsClass);
25             Response.Write("<br/>");
26             Response.Write("类的公共成员：");
27             Response.Write("<br/>");
28             MemberInfo[] memberInfos = type.GetMembers();//得到所有公共成员
29             foreach (var item in memberInfos)
30             {
31                 Response.Write(string.Format("{0}:{1}", item.MemberType, item));
32                 Response.Write("<br/>");
33             }
34         }

三：获取程序集信息

?

protected void Button2_Click(object sender, EventArgs e)

{

    //获取当前执行代码的程序集

    Assembly assem = Assembly.GetExecutingAssembly();

 

    Response.Write("程序集全名:"+assem.FullName);

    Response.Write("<br/>");

    Response.Write("程序集的版本："+assem.GetName().Version);

    Response.Write("<br/>");

    Response.Write("程序集初始位置:"+assem.CodeBase);

    Response.Write("<br/>");

    Response.Write("程序集位置："+assem.Location);

    Response.Write("<br/>");

    Response.Write("程序集入口："+assem.EntryPoint);

    Response.Write("<br/>");

 

    Type[] types = assem.GetTypes();

    Response.Write("程序集下包含的类型:");

    foreach (var item in types)

    {

        Response.Write("<br/>");

        Response.Write("类："+item.Name);

    }

}<br>

 四：反射调用方法

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protected void Page_Load(object sender, EventArgs e)  {        System.Reflection.Assembly ass = Assembly.LoadFrom(AppDomain.CurrentDomain.BaseDirectory+"bin\\WebApplication1.dll"); //加载DLL      System.Type t = ass.GetType("WebApplication1.MainPage");//获得类型          string name=typeof(MainPage).AssemblyQualifiedName;      System.Type t1 = Type.GetType(name); System.Type t2 = typeof(MainPage);        object o = System.Activator.CreateInstance(t);//创建实例        System.Reflection.MethodInfo mi = t.GetMethod("RunJs1");//获得方法        mi.Invoke(o, new object[] { this.Page, "alert('测试反射机制')" });//调用方法          System.Reflection.MethodInfo mi1 = t.GetMethod("RunJs");      mi1.Invoke(t, new object[] { this.Page, "alert('测试反射机制1')" });//调用方法  }<br>

 五：反射调用用户/自定义控件

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protected override void OnInit(EventArgs e)         {               //生成控件               CreateControl();             base.OnInit(e);         }           private void CreateControl()         {             Table tb = new Table();             TableRow dr = new TableRow();             TableCell cell = new TableCell();             Control c = <span style="color: rgb(255, 0, 0);">LoadControl("WebUserControl1.ascx"); </span>            cell.Controls.Add(c);             dr.Cells.Add(cell);             tb.Rows.Add(dr);             this.PlaceHolder1.Controls.Add(tb);         }           protected void Button1_Click(object sender, EventArgs e)         {             foreach (TableRow tr in PlaceHolder1.Controls[0].Controls)             {                 foreach (TableCell tc in tr.Controls)                 {                     foreach (Control ctl in tc.Controls)                     {                         if (ctl is UserControl)                         {                             Type type = ctl.GetType();                             System.Reflection.MethodInfo methodInfo = type.GetMethod("GetResult");                             string selectedValue = string.Concat(methodInfo.Invoke(ctl, new object[] { }));                               Response.Write(selectedValue);                             break;                         }                     }                 }             }         }<br>

六：反射实现工厂模式

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public partial class 反射 : System.Web.UI.Page     {         protected void Page_Load(object sender, EventArgs e)         {             string typeName = typeof(TestClass).AssemblyQualifiedName;             ITestInterface iface = RawGenericFactory.Create<ITestInterface>(typeName);             string result = iface.doSomething();             Response.Write(result);         }     }       public static class RawGenericFactory     {         public static T Create<T>(string typeName)         {             //Activator.CreateInstance 反射 根据程序集创建借口或者类             //Type.GetType() 根据名称获得程序集信息             //typeof(ConcertProduct).AssemblyQualifiedName             //_iproduct.GetType().AssemblyQualifiedName             return (T)Activator.CreateInstance(Type.GetType(typeName));         }     }       public interface ITestInterface     {         string doSomething();     }       public class TestClass : ITestInterface     {         public int Id { get; set; }         public override string ToString()         {             return Id.ToString();         }           public string doSomething()         {             return "ok";         }     }<br>

 七：自定义ORM框架

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[Orm.Table("TestORM")]         public class TestORM         {               [Orm.Colum("Id",DbType.Int32)]             public int Id { get; set; }             [Orm.Colum("UserName", DbType.String)]             public string UserName { get; set; }             [Orm.Colum("Password", DbType.String)]             public string Password { get; set; }             [Orm.Colum("CreatedTime", DbType.DateTime)]             public DateTime CreatedTime { get; set; }         }             protected void Button3_Click(object sender, EventArgs e)         {             TestORM t = new TestORM()             {                 Id=1,                 UserName="binfire",                 Password="xxx",                 CreatedTime=DateTime.Now             };             Orm.OrmHelp h=new Orm.OrmHelp();             h.Insert(t);         }   namespace Orm {     [AttributeUsageAttribute(AttributeTargets.Class, Inherited = false, AllowMultiple = false)]     public class TableAttribute : Attribute     {         //保存表名的字段         private string _tableName;           public TableAttribute()         {         }           public TableAttribute(string tableName)         {             this._tableName = tableName;         }           ///           /// 映射的表名(表的全名:模式名.表名)         ///         public string TableName         {             set             {                 this._tableName = value;             }             get             {                 return this._tableName;             }         }     }       [AttributeUsageAttribute(AttributeTargets.Property, Inherited = false, AllowMultiple = false)]     public class ColumAttribute : Attribute     {         private string _columName;           private DbType _dbType;             public ColumAttribute()         {         }           public ColumAttribute(string columName)             : this()         {             this._columName = columName;         }           public ColumAttribute(string columName, DbType dbType)             : this(columName)         {             this._dbType = dbType;         }           //列名         public virtual string ColumName         {             set             {                 this._columName = value;             }             get             {                 return this._columName;             }         }           //描述一些特殊的数据库类型         public DbType DbType         {             get { return _dbType; }             set { _dbType = value; }         }       }       public class OrmHelp     {         public void Insert(object table)         {             Type type = table.GetType();             //定义一个字典来存放表中字段和值的对应序列             Dictionary<string,string> columValue = new Dictionary<string,string>();             StringBuilder SqlStr = new StringBuilder();             SqlStr.Append("insert into ");             //得到表名子             TableAttribute temp = (TableAttribute)type.GetCustomAttributes(typeof(TableAttribute), false).First();             SqlStr.Append(temp.TableName);             SqlStr.Append("(");             PropertyInfo[] Propertys = type.GetProperties();             foreach (var item in Propertys)             {                 object[] attributes = item.GetCustomAttributes(false);                 foreach (var item1 in attributes)                 {                     //获得相应属性的值                     string value = table.GetType().InvokeMember(item.Name, System.Reflection.BindingFlags.GetProperty, null, table, null).ToString();                     ColumAttribute colum = item1 as ColumAttribute;                     if (colum != null)                     {                         columValue.Add(colum.ColumName, value);                     }                 }             }             //拼插入操作字符串             foreach (var item in columValue)             {                 SqlStr.Append(item.Key);                 SqlStr.Append(",");               }             SqlStr.Remove(SqlStr.Length - 1, 1);             SqlStr.Append(") values('");             foreach (var item in columValue)             {                 SqlStr.Append(item.Value);                 SqlStr.Append("','");                 }             SqlStr.Remove(SqlStr.Length - 2, 2);             SqlStr.Append(")");               HttpContext.Current.Response.Write(SqlStr.ToString());           }     } }