//引入命名空间
using System;
using System.IO;

class Test 
{
    
    public static void Main() 
    {
        string path = Path.GetTempFileName();
        var fi1 = new FileInfo(path);

        // Create a file to write to.
        using (StreamWriter sw = fi1.CreateText()) 
        {
            sw.WriteLine("Hello");
            sw.WriteLine("And");
            sw.WriteLine("Welcome");
        }	

        // Open the file to read from.
        using (StreamReader sr = fi1.OpenText()) 
        {
            var s = "";
            while ((s = sr.ReadLine()) != null) 
            {
                Console.WriteLine(s);
            }
        }

        try 
        {
            string path2 = Path.GetTempFileName();
            var fi2 = new FileInfo(path2);

            // Ensure that the target does not exist.
            fi2.Delete();

            // Copy the file.
            fi1.CopyTo(path2);
            Console.WriteLine($"{path} was copied to {path2}.");

            // Delete the newly created file.
            fi2.Delete();
            Console.WriteLine($"{path2} was successfully deleted.");
        } 
        catch (Exception e) 
        {
            Console.WriteLine($"The process failed: {e.ToString()}");
        }
    }
}

//引入命名空间
using System;
using System.IO;

public class MainClass
{
  public static void Main()
  {
    FileInfo MyFile = new FileInfo(@"c:\Test.txt");

    MyFile.Create();
  }
}