编码文件为Base64编码形式和解码Base64编码文件

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Collections;

namespace ToBase64
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        byte[] binaryData;
        byte[] frombaseData;
        string base64String,frombase64;
        private void button1_Click(object sender, EventArgs e)
        {
        
            try //读取当前目录下的base.txt文件
            {
                FileStream inFile = new System.IO.FileStream("base.txt",FileMode.Open,FileAccess.Read);
                binaryData=new Byte[inFile.Length];
                inFile.Read(binaryData, 0,(int)inFile.Length);
                inFile.Close();
            }
            catch (Exception err)
            {
                label1.Text = err.Message.ToString();
            }
           
            try//转换
            {
                base64String = System.Convert.ToBase64String(binaryData, 0, binaryData.Length);
            }
            catch(Exception err)
            {
                label1.Text=err.Message.ToString();
            }
            try//将转换后的数据写入到当前目录result.txt中
            {
                StreamWriter sw = new StreamWriter("result.txt", false, System.Text.Encoding.ASCII);
                sw.WriteLine(base64String);
                sw.Close();
            }
            catch (Exception err)
            {
                label1.Text = err.Message.ToString();
            }

        }

        private void button2_Click(object sender, EventArgs e)
        {
            try
            {//读取上次转换后的文件
                char[] base64CharArray;
                StreamReader inFile = new StreamReader("result.txt", System.Text.Encoding.ASCII);
                base64CharArray = new char[inFile.BaseStream.Length];
                inFile.Read(base64CharArray, 0, (int)inFile.BaseStream.Length);
                frombase64 = new string(base64CharArray);
            }
            catch(Exception err)
            {
                label1.Text = err.Message.ToString();
            }
            try
            {//转换
                frombaseData = System.Convert.FromBase64String(frombase64);
            }
            catch(Exception err)
            {
                label1.Text = err.Message.ToString();
            }
            try
            {//写入新的文本文件，和原来的内容相符
                FileStream fs = new FileStream("frombase64.txt", System.IO.FileMode.Create, System.IO.FileAccess.Write);
                fs.Write(frombaseData, 0, binaryData.Length);
                fs.Close();
            }
            catch (Exception err)
            {
                label1.Text = err.Message.ToString();
            }
        }
    }
}