☀️ 学会编程入门必备 C# 最基础知识介绍—— C# 高级文件操作(文本文件的读写、二进制文件的读写、Windows 文件系统的操作)

using System;
using System.IO;
namespace FileApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            try
            {
                // 创建一个 StreamReader 的实例来读取文件 
                // using 语句也能关闭 StreamReader
                using (StreamReader sr = new StreamReader("c:/jamaica.txt"))
                {
                    string line;
                    // 从文件读取并显示行，直到文件的末尾 
                    while ((line = sr.ReadLine()) != null)
                    {
                        Console.WriteLine(line);
                    }
                }
            }
            catch (Exception e)
            {
                // 向用户显示出错消息
                Console.WriteLine("The file could not be read:");
                Console.WriteLine(e.Message);
            }
            Console.ReadKey();
        }
    }
}

using System;
using System.IO;
namespace FileApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            string[] names = new string[] {"Zara Ali", "Nuha Ali"};
            using (StreamWriter sw = new StreamWriter("names.txt"))
            {
                foreach (string s in names)
                {
                    sw.WriteLine(s);
                }
            }
            // 从文件中读取并显示每行
            string line = "";
            using (StreamReader sr = new StreamReader("names.txt"))
            {
                while ((line = sr.ReadLine()) != null)
                {
                    Console.WriteLine(line);
                }
            }
            Console.ReadKey();
        }
    }
}

实例
using System;
using System.IO;
namespace BinaryFileApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            BinaryWriter bw;
            BinaryReader br;
            int i = 25;
            double d = 3.14157;
            bool b = true;
            string s = "I am happy";
            // 创建文件
            try
            {
                bw = new BinaryWriter(new FileStream("mydata",
                                FileMode.Create));
            }
            catch (IOException e)
            {
                Console.WriteLine(e.Message + "\n Cannot create file.");
                return;
            }
            // 写入文件
            try
            {
                bw.Write(i);
                bw.Write(d);
                bw.Write(b);
                bw.Write(s);
            }
            catch (IOException e)
            {
                Console.WriteLine(e.Message + "\n Cannot write to file.");
                return;
            }
            bw.Close();
            // 读取文件
            try
            {
                br = new BinaryReader(new FileStream("mydata",
                                FileMode.Open));
            }
            catch (IOException e)
            {
                Console.WriteLine(e.Message + "\n Cannot open file.");
                return;
            }
            try
            {
                i = br.ReadInt32();
                Console.WriteLine("Integer data: {0}", i);
                d = br.ReadDouble();
                Console.WriteLine("Double data: {0}", d);
                b = br.ReadBoolean();
                Console.WriteLine("Boolean data: {0}", b);
                s = br.ReadString();
                Console.WriteLine("String data: {0}", s);
            }
            catch (IOException e)
            {
                Console.WriteLine(e.Message + "\n Cannot read from file.");
                return;
            }
            br.Close();
            Console.ReadKey();
        }
    }
}

using System;
using System.IO;
namespace WindowsFileApplication
{
    class Program
    {
        static void Main(string[] args)
        {
            // 创建一个 DirectoryInfo 对象
            DirectoryInfo mydir = new DirectoryInfo(@"c:\Windows");
            // 获取目录中的文件以及它们的名称和大小
            FileInfo [] f = mydir.GetFiles();
            foreach (FileInfo file in f)
            {
                Console.WriteLine("File Name: {0} Size: {1}",
                    file.Name, file.Length);
            }
            Console.ReadKey();
        }
    }
}