TargetException异常的处理

我是C#的初学者。
下面代码是我复制自MSDN中的。运行时，
在 “ Object ret = m.Invoke(o, new Object[] { 42 });   ”处
有错误提示：
             未处理的TargetException ：非静态方法需要一个目标

这个问题，怎么解决？
谢谢

using System;
using System.Configuration;
using System.Security.Permissions;
using System.Reflection;

namespace ConsoleApplication1
{

    [assembly: AssemblyVersionAttribute("1.0.2000.0")]

    public class Example
    {
        private int factor;
        public Example(int f)
        {
            factor = f;
        }

        public int SampleMethod(int x)
        {
            Console.WriteLine("\nExample.SampleMethod({0}) executes.", x);
            return x * factor;
        }

        public static void Main()
        {
            Assembly assem = Assembly.GetExecutingAssembly();

            Console.WriteLine("Assembly Full Name:");
            Console.WriteLine(assem.FullName);

            // The AssemblyName type can be used to parse the full name.
            AssemblyName assemName = assem.GetName();
            Console.WriteLine("\nName: {0}", assemName.Name);
            Console.WriteLine("Version: {0}.{1}",
                assemName.Version.Major, assemName.Version.Minor);

            Console.WriteLine("\nAssembly CodeBase:");
            Console.WriteLine(assem.CodeBase);

            // Create an object from the assembly, passing in the correct number
            // and type of arguments for the constructor.
            Object o = assem.CreateInstance("Example", false,
                BindingFlags.ExactBinding,
                null, new Object[] { 2 }, null, null);
                // Make a late-bound call to an instance method of the object.
            MethodInfo m = assem.GetType("ConsoleApplication1.Example").GetMethod("SampleMethod");

            Object ret = m.Invoke(o, new Object[] { 42 });                 //出错的地方

            Console.WriteLine("SampleMethod returned {0}.", ret);
            Console.WriteLine("\nAssembly entry point:");
            Console.WriteLine(assem.EntryPoint);
            Console.ReadLine();
        }
    }


} --------------------编程问答-------------------- Object o = assem.CreateInstance("Example", false,
你的 o 是null吧，没有创建成功 --------------------编程问答-------------------- Object o = assem.CreateInstance("Example", false,
  BindingFlags.ExactBinding,
  null, new Object[] { 2 }, null, null);

Object o = assem.CreateInstance("ConsoleApplication1.Example", false,
  BindingFlags.ExactBinding,
  null, new Object[] { 2 }, null, null);

你通过反射创建对象的时候,没有成功,返回的是Null, 原因是你的typeName错了.要写全,谢谢.切记. --------------------编程问答--------------------

补充：.NET技术 ,  C#