以前使用的File是操作小的文本文件,用的并不常见,FileStream(操作字节),可以操作所有格式的文件,用途较广泛

下面做一个通过文件流给文件加密解密的小软件. 

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.IO;using System.Linq;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace 文件加密{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private void btnFile_Click(object sender, EventArgs e)        {            OpenFileDialog ofd = new OpenFileDialog();            ofd.Title = "请选择要加密的文件";            //初始路径            ofd.InitialDirectory = @"C:\Users\home\Desktop";            ofd.Filter = "所有文件|*.*";            ofd.ShowDialog();            txtFile.Text = ofd.FileName;        }        private void btnCode_Click(object sender, EventArgs e)        {            SaveFileDialog sfd = new SaveFileDialog();            sfd.Title = "请选择要保存文件的路径";            sfd.InitialDirectory = @"C:\Users\home\Desktop";            sfd.Filter = "所有文件|*.*";            sfd.ShowDialog();            txtCodeFile.Text = sfd.FileName;            //调用方法            MakeCode( "加密");        }        private void btnUnCode_Click(object sender, EventArgs e)        {            SaveFileDialog sfd = new SaveFileDialog();            sfd.Title = "请选择要保存文件的路径";            sfd.InitialDirectory = @"C:\Users\home\Desktop";            sfd.Filter = "所有文件|*.*";            sfd.ShowDialog();            txtCodeFile.Text = sfd.FileName;            //调用方法            MakeCode("解密");        }        public void MakeCode(string content)         {            //1 先读取文件            using (FileStream fsRead = new FileStream(txtFile.Text.Trim(), FileMode.OpenOrCreate, FileAccess.Read))            {                using (FileStream fsWrite = new FileStream(txtCodeFile.Text.Trim(), FileMode.OpenOrCreate, FileAccess.Write))                {                    //设置进度条                    progressBar1.Maximum = (int)fsRead.Length;                    byte[] buffer = new byte[1024 * 1024 * 5];                    while (true)                    {                        int r = fsRead.Read(buffer, 0, buffer.Length);                        if (r == 0)                        {                            break;                        }                        byte passWord = 0;                        if (byte.TryParse(txtPassword.Text.Trim(), out passWord)&& content.Equals("加密"))                        {                            for (int i = 0; i < buffer.Length; i++)                            {                                buffer[i] += passWord;                            }                        }                        if (byte.TryParse(txtPassword.Text.Trim(), out passWord) && content.Equals("解密"))                        {                            for (int i = 0; i < buffer.Length; i++)                            {                                buffer[i] -= passWord;                            }                        }                        fsWrite.Write(buffer, 0, r);                        progressBar1.Value = (int)fsWrite.Length;                    }                }                MessageBox.Show("保存成功!");            }        }                 }}

1 将普通视频文件通过此工具加密

2 现在打开文件

3 解密成功后打开文件