C# 寫入文本內容, 如果文件不存在則創建

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;

namespace ConsoleApp17
{
    class Program
    {
        static void Main(string[] args)
        {
            // 寫入文本內容, 如果文件不存在則創建
            // append=false, 則為覆蓋方式寫入
            WriteDoc("D:\\001.txt", "寫入內容", true, Encoding.UTF8);
            Console.WriteLine("ok");
            Console.Read();
        }

        /// <summary>
        /// 創建文本文件并寫入內容
        /// 例如：創建readme.txt
        /// </summary>
        /// <param name="path">文件路徑</param>
        /// <param name="input">寫入內容</param>
        /// <param name="append">是否追加</param>
        /// <param name="encode">文件編碼</param>
        public static void WriteDoc(string path, string input, bool append, Encoding encode)
        {
            try
            {
                using (StreamWriter sw = new StreamWriter(path, append, encode))
                {
                    sw.Write(input);
                }
            }
            catch
            {
                throw;
            }
        }

        /// <summary>
        /// 創建文本文件并寫入內容
        /// </summary>
        /// <param name="path">文件路徑</param>
        /// <param name="input">傳入Stream</param>
        /// <param name="append">是否追加</param>
        /// <param name="encode">選擇編碼</param>
        /// <returns>
        /// true->寫入文本成功
        /// false->寫入失敗（檢查路徑與權限）
        /// </returns>
        public static void WriteDoc(string path, Stream input, bool append, Encoding encode)
        {
            try
            {
                // 把 Stream 轉換成 byte[]
                byte[] buffer = new byte[input.Length];
                // 設置當前流的位置為流的開始
                input.Seek(0, SeekOrigin.Begin);
                input.Read(buffer, 0, buffer.Length);
                input.Flush();
                // 把 byte[] 寫入文件
                using (StreamWriter sw = new StreamWriter(path, append, encode))
                {
                    sw.Write(encode.GetString(buffer));
                }
            }
            catch
            {
                throw;
            }
        }
    }
}