C#使用Streamwriter打开文件的方法

using System;
using System.IO;
public class KtoD1 {
 public static void Main() {
  string str;
  StreamWriter fstr_out;
  // Open the file directly using StreamWriter.
  try {
   fstr_out = new StreamWriter("test.txt");
  }
  catch(IOException exc) {
   Console.WriteLine(exc.Message + "Cannot open file.");
   return ;
  }
  Console.WriteLine("Enter text ('stop' to quit).");
  do {
   Console.Write(": ");
   str = Console.ReadLine();
   if(str != "stop") {
    str = str + "\r\n"; // add newline
    try {
     fstr_out.Write(str);
    } catch(IOException exc) {
     Console.WriteLine(exc.Message + "File Error");
     return ;
    }
   }
  } while(str != "stop");
  fstr_out.Close();
 }
}