System.IO (เส้นทางและสตรีม)

เบื้องต้นเกี่ยวกับ System.IO

พื้นฐานของ Path

using System;
using System.IO;

public class Program
{
  public static void Main(string[] args)
  {
    // Build a safe path (handles separators)
    string folder = "data";
    string file = "notes.txt";
    string path = Path.Combine(folder, file);

    Console.WriteLine("File name: " + Path.GetFileName(path));
    Console.WriteLine("Directory: " + Path.GetDirectoryName(path));
    Console.WriteLine("Full path: " + Path.GetFullPath(path));
  }
}

สร้างและเขียน

using System;
using System.IO;

public class Program
{
  public static void Main(string[] args)
  {
    string folder = "data";
    if (!Directory.Exists(folder))
    {
      Directory.CreateDirectory(folder); // create if missing
    }

    string path = Path.Combine(folder, "hello.txt");
    // Simple one-shot write
    File.WriteAllText(path, "Hello file!");
    Console.WriteLine("Wrote: " + path);
  }
}

การอ่านอย่างปลอดภัย

using System;
using System.IO;

public class Program
{
  public static void Main(string[] args)
  {
    string path = Path.Combine("data", "hello.txt");

    if (File.Exists(path))
    {
      using (StreamReader r = new StreamReader(path))
      {
        string content = r.ReadToEnd(); // read all
        Console.WriteLine("Content: " + content);
      } // Dispose closes the file
    }
    else
    {
      Console.WriteLine("Missing file: " + path);
    }
  }
}

การเขียนอย่างปลอดภัย

using System;
using System.IO;

public class Program
{
  public static void Main(string[] args)
  {
    string path = Path.Combine("data", "log.txt");

    // Append = true so we keep old content
    using (StreamWriter w = new StreamWriter(path, true))
    {
      w.WriteLine(DateTime.UtcNow.ToString("u") + " - started");
      w.WriteLine("Work done");
    } // closed here

    Console.WriteLine("Appended to log: " + path);
  }
}

การตรวจสอบและเคล็ดลับ

กฎความปลอดภัยของสตรีม

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