问题描述

C#新手，看到书上一个 关于foreach的例子，无法运行

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace foreachApp
{
class Program
{
public static void Main()
{

        IDictionary environment = Environment.GetEnvironmentVariables();        Console.WriteLine(""环境变量名t=t环境变量值"");         //遍历environment中所有键值        foreach (string environment in environment.Keys)        {            Console.WriteLine(""{0}t=t{1}""environmentKeyenvironment [environmentKey].ToString());        }    }}

}
大家帮忙看看哪里错误了，多谢

解决方案

IDictionary environment = Environment.GetEnvironmentVariables();
Console.WriteLine(""环境变量名t=t环境变量值"");
//遍历environment中所有键值
foreach (string key in environment.Keys)
{

            Console.WriteLine(""{0}t=t{1}"" key environment[key].ToString());        }

解决方案二：
添加 using System.Collections;

解决方案三：
给你个完整的代码
using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Test
{
class Program
{
static void Main(string[] args)
{
IDictionary environment = Environment.GetEnvironmentVariables();
Console.WriteLine(""环境变量名t=t环境变量值"");
//遍历environment中所有键值
foreach (DictionaryEntry de in environment)
{

            Console.WriteLine(""{0}t=t{1}"" de.Key de.Value);        }    }}

}

解决方案四：
代码没问题，可以执行
完整代码：

 using System;using System.Collections;class Sample {    public static void Main()     {    Console.WriteLine();    Console.WriteLine(""GetEnvironmentVariables: "");    IDictionary environmentVariables = Environment.GetEnvironmentVariables();    foreach (DictionaryEntry de in environmentVariables)        {        Console.WriteLine(""  {0} = {1}"" de.Key de.Value);        }    }}