基础代码：
1 public interface IDBHelper
2 {
3 void Query();
4 }
5 public class DBHelper : IDBHelper
6 {
7 public int Id { get; set; }
8 public string Name { get; set; }
9
10 public DBHelper()
11 {
12 //Console.WriteLine("这里是{0}的无参构造函数", this.GetType().FullName);
13 }
14
15 public void Query()
16 {
17 //Console.WriteLine("这里是{0}的Query", this.GetType().FullName);
18 }
19
20 }
1. 反射加载dll，读取module
动态加载:
1 Assembly assembly = Assembly.Load("当前路径下的dll文件");// 默认加载当前路径的dll文件，不需要后缀
2 Assembly assembly1 = Assembly.LoadFile("完整路径");// 必须是完整路径-需要后缀.dll
3 Assembly assembly2 = Assembly.LoadFrom("当前路径|或者是完整路径");// 可以是当前路径 也可以是完整路径-需要后缀.dll
2. 读取module、类、方法
1 Console.WriteLine("************GetModules**********");
2 foreach (var item in assembly.GetModules())
3 {
4 Console.WriteLine(item.FullyQualifiedName);
5 }
6 foreach (var item in assembly.GetTypes())
7 {
8 Console.WriteLine(item.FullName);
9 }
10 Type typeDBHelper = assembly.GetType("Ruanmou.DB.Sqlserver.DBHelper");//2 获取类型-指定名称获取类型
11 foreach (var item in typeDBHelper.GetConstructors())
12 {
13 Console.WriteLine(item.Name);
14 }
15 foreach (var item in typeDBHelper.GetProperties())
16 {
17 Console.WriteLine(item.Name);
18 }
19 foreach (var item in typeDBHelper.GetMethods())
20 {
21 Console.WriteLine(item.Name);
22 }
23 foreach (var item in typeDBHelper.GetFields())
24 {
25 Console.WriteLine(item.Name);
26 }
3.简单工厂：
配置文件：
1 <?xml version="1.0" encoding="utf-8" ?> 2 <configuration> 3 <startup> 4 <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" /> 5 </startup> 6 <appSettings> 7 <add key="IDBHelper" value="Ruanmou.DB.Sqlserver.DBHelper,Ruanmou.DB.Sqlserver"/> 8 </appSettings> 9 </configuration>
1 public class SimpleFactory
2 {
3 private static string IDBHelperConfig = ConfigurationManager.AppSettings["IDBHelper"];
4
5 public static IDBHelper CreateDBHelper()
6 {
7 string dllName = IDBHelperConfig.Split(‘,‘)[1];
8 string className = IDBHelperConfig.Split(‘,‘)[0];
9
10 Assembly assembly = Assembly.Load(dllName);
11 Type type = assembly.GetType(className);
12 object oObject = Activator.CreateInstance(type);
13 return (IDBHelper)oObject;
14
15 }
16 }
对比一下,个人感觉就是封装了一下.不过用起来很方便的啦！
Console.WriteLine("**************************************************");
{
object oDBHelper = Activator.CreateInstance(typeDBHelper);// 创建对象
IDBHelper dbHelperReflection = (IDBHelper)oDBHelper;
dbHelperReflection.Query();
//简单工厂
IDBHelper dbHelperFactory = SimpleFactory.CreateDBHelper();
dbHelperFactory.Query();
}
4.反射创建对象,反射+简单工厂+配置文件. ------------------ 破坏单例 创建泛型
1 namespace Ruanmou.DB.Sqlserver
2 {
3 /// <summary>
4 /// 反射测试类
5 /// </summary>
6 public class ReflectionTest
7 {
8 public int Id { get; set; }
9 public string Name { get; set; }
10
11 public string Field = null;
12 public static string FieldStatic = null;
13
14
15 #region 构造函数
16 public ReflectionTest()
17 {
18 Console.WriteLine("这里是{0}无参数构造函数", this.GetType());
19 }
20
21 public ReflectionTest(string name)
22 {
23 Console.WriteLine("这里是{0} 有参数构造函数", this.GetType());
24 }
25
26 public ReflectionTest(int id, string name)
27 {
28 Console.WriteLine("这里是{0} 有参数构造函数", this.GetType());
29 }
30 #endregion
31
32 public static void ShowStatic(string name)
33 {
34 Console.WriteLine("这里是{0}的ShowStatic", typeof(ReflectionTest));
35 }
36
37 public void ShowGeneric<T>(string name)
38 {
39 Console.WriteLine("这里是{0}的ShowStatic T={1}", this.GetType(), typeof(T));
40 }
41
42 public void Show1()
43 {
44 Console.WriteLine("这里是{0}的Show1", this.GetType());
45 }
46
47 public void Show2(int id)
48 {
49
50 Console.WriteLine("这里是{0}的Show2", this.GetType());
51 }
52
53 public void Show3()
54 {
55 Console.WriteLine("这里是{0}的Show3_1", this.GetType());
56 }
57
58 public void Show3(int id, string name)
59 {
60 Console.WriteLine("这里是{0}的Show3", this.GetType());
61 }
62
63 public void Show3(string name, int id)
64 {
65 Console.WriteLine("这里是{0}的Show3_2", this.GetType());
66 }
67
68 public void Show3(int id)
69 {
70
71 Console.WriteLine("这里是{0}的Show3_3", this.GetType());
72 }
73
74 public void Show3(string name)
75 {
76
77 Console.WriteLine("这里是{0}的Show3_4", this.GetType());
78 }
79
80 private void Show4(string name)
81 {
82 Console.WriteLine("这里是{0}的Show4", this.GetType());
83 }
84
85 }
86 }
1 /// <summary>
2 /// 单例模式
3 /// </summary>
4 public sealed class Singleton
5 {
6 private Singleton()
7 {
8 Console.WriteLine("初始化一次");
9 }
10
11 private static Singleton Instance = new Singleton();
12
13 public static Singleton CreateInstance()
14 {
15 return Instance;
16 }
17 }
单例就是一个类只有一个实例
对构造函数的调用:
反射创建实例时,要指定类型.然后再指定构造函数的参数.
1 {
2 Console.WriteLine("**************带参数的构造函数****************");
3 Type typeTest = assembly.GetType("Ruanmou.DB.Sqlserver.ReflectionTest");
4 foreach (var item in typeTest.GetConstructors())
5 {
6 Console.WriteLine(item.Name);
7 }
8 Activator.CreateInstance(typeTest);
9 Activator.CreateInstance(typeTest, "demon");
10 Activator.CreateInstance(typeTest, 11, "限量版(397-限量版)");
11 //Activator.CreateInstance(typeTest, "限量版(397-限量版)", 11);---这里调用时将两个不同类型的参数位置放置错误,导致错误.所以注释了.
12
13 //该反射破坏了单例
14 Type typeSingleton = assembly.GetType("Ruanmou.DB.Sqlserver.Singleton");
15 Activator.CreateInstance(typeSingleton, true);
16 Activator.CreateInstance(typeSingleton, true);
17 //泛型
18 Type typeGeneric = assembly.GetType("Ruanmou.DB.Sqlserver.GenericClass`1");
19 typeGeneric = typeGeneric.MakeGenericType(typeof(int));//反射调用泛型时指定类型的方法
20 Activator.CreateInstance(typeGeneric);
21 }
5. 反射调用实例方法、静态方法、重载方法 -------------调用私有方法 调用泛型方法(这个666)
1 Console.WriteLine("**************反射调用实例方法****************");
2 Type typeTest = assembly.GetType("Ruanmou.DB.Sqlserver.ReflectionTest");
3 object oTest = Activator.CreateInstance(typeTest);
4
5 foreach (var item in typeTest.GetMethods())
6 {
7 Console.WriteLine(item.Name);
8 }
9 {
10 MethodInfo method = typeTest.GetMethod("Show1");
11 method.Invoke(oTest, null);
12 }
13 {
14 MethodInfo method = typeTest.GetMethod("Show2");
15 method.Invoke(oTest, new object[] { 11 });//调用方法时第一个参数指定实例
16 }
17 {
18 MethodInfo method = typeTest.GetMethod("ShowStatic");
19 method.Invoke(null, new object[] { "KOBE→Bryant" });//静态方法的第一个参数为null-是因为静态方法的调用不需要指定实例
20 } //以下对应不同的重载方法:
21 {
22 MethodInfo method = typeTest.GetMethod("Show3", new Type[] { });
23 method.Invoke(oTest, null);
24 }
25 {
26 MethodInfo method = typeTest.GetMethod("Show3", new Type[] { typeof(int) });
27 method.Invoke(oTest, new object[] { 11 });
28 }
29 {
30 MethodInfo method = typeTest.GetMethod("Show3", new Type[] { typeof(string) });
31 method.Invoke(oTest, new object[] { "限量版(397-限量版)" });
32 }
33 {
34 MethodInfo method = typeTest.GetMethod("Show3", new Type[] { typeof(string), typeof(int) });
35 method.Invoke(oTest, new object[] { "书呆熊@拜仁", 22 });
36 }
37 {
38 MethodInfo method = typeTest.GetMethod("Show3", new Type[] { typeof(int), typeof(string) });
39 method.Invoke(oTest, new object[] { 33, "不懂微软" });
40 } //除了参数,指定控制绑定和由反射执行的成员和类型搜索方法的标志,可以调用私有方法.
41 {
42 MethodInfo method = typeTest.GetMethod("Show4", BindingFlags.Instance | BindingFlags.NonPublic);
43 method.Invoke(oTest, new object[] { "有木有" });
44 }
45 {
46 MethodInfo method = typeTest.GetMethod("ShowGeneric");
47 method = method.MakeGenericMethod(typeof(string));
48 method.Invoke(oTest, new object[] { "有木有" });
49 }
6. 反射字段和属性，分别获取值和设置值
1 Console.WriteLine("**************反射字段和属性****************");
2 ReflectionTest test = new ReflectionTest();
3 test.Id = 11;
4 test.Name = "妙为";
5
6 Type typeTest = assembly.GetType("Ruanmou.DB.Sqlserver.ReflectionTest");
7 object oTest = Activator.CreateInstance(typeTest);
8 //foreach (var item in typeTest.GetFields(BindingFlags.Instance | BindingFlags.Static | BindingFlags.Public))
9 //{
10 // Console.WriteLine(item.Name);
11 //}
12 foreach (var prop in typeTest.GetProperties())
13 {
14 Console.WriteLine(prop.GetValue(oTest));
15 Console.WriteLine(prop.Name);
16 if (prop.Name.Equals("Id"))
17 {
18 prop.SetValue(oTest, 22);
19 }
20 else if (prop.Name.Equals("Name"))
21 {
22 prop.SetValue(oTest, "Bond(331-object)");
23 }
24
25 Console.WriteLine(prop.GetValue(oTest));
26 }
7. 反射的好处和局限 好处就是动态
1 {
2 Stopwatch watch = new Stopwatch();
3 watch.Start();
4 for (int i = 0; i < 100000; i++)
5 {
6 DBHelper dbHelper = new DBHelper();
7 dbHelper.Id = 1;
8 dbHelper.Name = "仗劍走天涯";
9 dbHelper.Query();
10 }
11 watch.Stop();
12 Console.WriteLine("普通方式花费{0}ms", watch.ElapsedMilliseconds);
13 }
14 {
15 Stopwatch watch = new Stopwatch();
16 watch.Start();
17 for (int i = 0; i < 100000; i++)
18 {
19 Assembly assemblyTest = Assembly.Load("Ruanmou.DB.Sqlserver");
20
21 Type typeTest = assemblyTest.GetType("Ruanmou.DB.Sqlserver.DBHelper");
22 object oTest = Activator.CreateInstance(typeTest);
23
24 foreach (var prop in typeTest.GetProperties())
25 {
26 if (prop.Name.Equals("Id"))
27 {
28 prop.SetValue(oTest, 1);
29 }
30 else if (prop.Name.Equals("Name"))
31 {
32 prop.SetValue(oTest, "仗劍走天涯");
33 }
34 }
35 MethodInfo method = typeTest.GetMethod("Query");
36 method.Invoke(oTest, null);
37 }
38 watch.Stop();
39 Console.WriteLine("反射方式花费{0}ms", watch.ElapsedMilliseconds);
40 }
局限：避开了编译器的检查,运行时错误才会暴露出来.(如果有的话)
性能损耗
时间： 2024-12-22 01:45:42