日期:2010-02-22  浏览次数:20441 次

这个话题是仁者见仁,智者见智,这里我也谈谈自己对.NET反射封装的思路,请先看下面的示例代码:
  static void Main(string[] args)
  {
  Person liu = new Person("liu", 26);
  Reflector reflector = new Reflector(liu);
  //获取属性
  string name = reflector.Property<string>("Name");
  int age = reflector.Property<int>("Age");
  Console.WriteLine(name + " " + age);
  //修改属性
  age = reflector.SetProperty<int>("Age", 27);
  Console.WriteLine(name + " " + age);
  //获取过程
  Proc<string> sayHello = reflector.Proc<string>("SayHello");
  sayHello("Ling");
  //获取函数
  Func<int> getAge = reflector.Func<int>("GetAge");
  age = getAge();
  Console.WriteLine(age);
  Console.ReadLine();
  }
  public class Person
  {
  private string name;
  private int age;
  public Person(string name, int age)
  {
  this.name = name;
  this.age = age;
  }
  public string Name
  {
  get { return name; }
  }
  public int Age
  {
  get { return age; }
  set { age = value; }
  }
  public void SayHello(string who)
  {
  Console.WriteLine("Say Hello to " + who);
  }
  public int GetAge()
  {
  return age;
  }
  }
  相信您已经从代码看出了封装的思路:利用泛型和泛型委托为动态的反射添加静态的类型约束。下面我们就来简单看一下Reflector实现的关键部分:
  public delegate void Proc();
  public delegate void Proc<T1>(T1 arg1);
  public delegate void Proc<T1, T2>(T1 arg1, T2 args);
  public delegate void Proc<T1, T2, T3>(T1 arg1, T2 args, T3 arg3);
  public delegate void Proc<T1, T2, T3, T4>(T1 arg1, T2 args, T3 arg3, T4 arg4);
  public delegate void Proc<T1, T2, T3, T4, T5>(T1 arg1, T2 args, T3 arg3, T4 arg4, T5 arg5);
  public delegate R Func<R>();
  public delegate R Func<T1, R>(T1 arg1);
  public delegate R Func<T1, T2, R>(T1 arg1, T2 args);
  public delegate R Func<T1, T2, T3, R>(T1 arg1, T2 args, T3 arg3);
  public delegate R Func<T1, T2, T3, T4, R>(T1 arg1, T2 args, T3 arg3, T4 arg4);
  public delegate R Func<T1, T2, T3, T4, T5, R>(T1 arg1, T2 args, T3 arg3, T4 arg4, T5 arg5);
  public class Reflector
  {
  private object target;
  public object Target
  {
  get { return target; }
  }
  public T Property<T>(string name)
  {
  PropertyInfo pi = target.GetType().GetProperty(name, typeof(T));
  if (null != pi && pi.CanRead)
  {
  object value = pi.GetValue(target, null);
  if (null != value)
  {
  return (T)value;
  }
  }
  return default(T);
  }
  public T SetProperty<T>(string name, T value)
  {
  PropertyInfo pi = target.GetType().GetProperty(name, typeof(T));
  if (null != pi && pi.CanWrite)
  {
  pi.SetValue(target, value, null);
  }
  return value;
  }
  public Proc Proc(string name)
  {
  MethodInfo mi = target.GetType().GetMethod(name, Type.EmptyTypes);
  if (null != mi)
  {
  return Delegate.CreateDelegate(typeof(Proc), target, mi.Name, false) as Proc;
  }
  return null;
  }
  public Proc<T> Proc<T>(string name)
  {
  MethodInfo mi = target.GetType().GetMethod(name, new Type[] { typeof(T) });
  if (null != mi)
  {
  return Delegate.CreateDelegate(typeof(Proc<T>), target, mi.Name, false) as Proc<T>;
  }
  return null;
  }
  public Proc<T1, T2> Proc<T1, T2>(string name)
  {
  MethodInfo mi = target.GetType().GetMethod(name, new Type[] { typeof(T1), typeof(T2) });
  if (null != mi)
  {
  return Delegate.CreateDelegate(typeof(Proc<T1, T2>), target, mi