C#反射机制（转自Binfire博客）
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: #ff0000;">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()); } }} |
