一、从控制台读取东西代码片断：

using System;

class TestReadConsole
{
    public static void Main()
    {
        Console.Write("Enter your name:");
        string strName = Console.ReadLine();
        Console.WriteLine(" Hi "+ strName);
    }
}
 
二、读文件代码片断： (请先在C盘根目录下新建记事本,内容写上“MY NAME IS PC126”保存为test)
using System;
using System.IO;
 
public class TestReadFile
{
    public static void Main(String[] args)
    {
        // Read text file C:/test.txt
        FileStream fs = new FileStream("c:/test.txt" , FileMode.Open, FileAccess.Read);
        StreamReader sr = new StreamReader(fs);
       
        String line=sr.ReadLine();
        while (line!=null)
        {
            Console.WriteLine(line);
            line=sr.ReadLine();
        }  
       
        sr.Close();
        fs.Close();
    }
}
 
三、创建文件及写入文件（编译运行完成结果请查看 C盘）
using System;
using System.IO;
 
public class TestWriteFile
{
    public static void Main(String[] args)
    {
        // Create a text file C:/test.txt
        FileStream fs = new FileStream("c:/test1.txt" , FileMode.OpenOrCreate, FileAccess.Write);
        StreamWriter sw = new StreamWriter(fs);
        // Write to the file using StreamWriter class
        sw.BaseStream.Seek(0, SeekOrigin.End);
        sw.WriteLine( "First Line :my name is pc126");
        sw.WriteLine( "Second Line :how are you!");
        sw.Flush();
    }
}
 
四、拷贝文件：
using System;
using System.IO;
 
class TestCopyFile
{
    public static void Main()
    {
        File.Copy("c:/test1.txt", "C:/test2.txt" );
    }
}
 
五、移动文件并改名
using System;
using System.IO;
 
class TestMoveFile
{
    public static void Main()
    {
        File.Move("c:/test2.txt", "d:/pc126.txt" );
    }
}
 
六、使用计时器：
using System;
using System.Timers;
 
class TestTimer
{
    public static void Main()
    {
        Timer timer = new Timer();
        timer.Elapsed += new ElapsedEventHandler( DisplayTimeEvent );
        timer.Interval = 1000;
        timer.Start();
        timer.Enabled = true;
        while ( Console.Read() != 'q' )
        {
             //-------------
        }
    }
    public static void DisplayTimeEvent( object source, ElapsedEventArgs e )
    {
        Console.Write("\r{0}", DateTime.Now);
    }
}
 
七、调用外部程序：
 
class Test
{
    static void Main(string[] args)
    {
    System.Diagnostics.Process.Start("c:/windows/notepad.exe");
    }
}