代码看不懂, 求解释,关于反射
- C# code
using System;using System.Reflection;public class AssemblyDemo{ public static void Main(string[] args) { int i,j; if (args.GetLength(0) < 1) { Console.WriteLine("usage is AssemblyDemo < library_name >"); } else { Assembly assembly = Assembly.LoadFrom(args[0]); Type[] types = assembly.GetTypes(); Console.WriteLine(assembly.GetName().Name + " contains the following types"); for (i = 0 ; i < types.GetLength(0); ++i) { Console.WriteLine("\r(" + i + ") " + types[i].Name); } i = types.Length - 1; Console.Write("make selection(0-" + i + "):"); j = Convert.ToInt32(Console.ReadLine()); Console.WriteLine(); if (types[j].IsSubclassOf(typeof(Sport))) { ConstructorInfo ci = types[j].GetConstructor(new Type[0]); Sport sport = (Sport)ci.Invoke(new Object[0]); Console.WriteLine(sport.GetName() + " has " + sport.GetDuration()); } else { Console.WriteLine(types[j].Name + " is not a sub-class of Sport"); } } }}
上面代码中
- C# code
ConstructorInfo ci = types[j].GetConstructor(new Type[0]); Sport sport = (Sport)ci.Invoke(new Object[0]);
这两句中的 new Type[0] 和 new Object[0] 真的 不明白, 求明白的同学帮忙讲讲, 多谢了
[解决办法]
Type.GetConstructor Method (Type[]) 因为方法的签名是type的数组,所以ConstructorInfo ci = types[j].GetConstructor(new Type[0]);这里给了一个空的数组,意思就是获取Sport类的无参构造函数。
Sport sport = (Sport)ci.Invoke(new Object[0]);意思是调用这个构造函数,因为是无参的构造函数,当然是给一个空的Object数组啦。