MD5计算器,字符串&文件校验

练习所作

下面是将文件和字符串转化为md5值代码

 private static string GetMd5FromFile(string path)        {            using (MD5 md=MD5.Create())            {                using (FileStream fsRead = File.OpenRead(path))                {                    byte[] buffer = md.ComputeHash(fsRead);                    md.Clear();                    StringBuilder sbMD5 = new StringBuilder();                    for (int i = 0; i < buffer.Length; i++)                    {                        sbMD5.Append(buffer[i].ToString("X2"));                    }                    return sbMD5.ToString().ToLower();                }            }        } private static string GetMD5FromString(string str)        {            using (MD5 md=MD5.Create())            {                byte[] strBuffer = Encoding.Default.GetBytes(str);                byte[] mdBuffer = md.ComputeHash(strBuffer);                StringBuilder sbMd5 = new StringBuilder();                for (int i = 0; i < mdBuffer.Length; i++)                {                    sbMd5.Append(mdBuffer[i].ToString("X2"));                }                return sbMd5.ToString().ToLower();            }        }

无论是文件还是字符串用ComputeHash()方法,传入的是byte[] ,返回值也是byte[].

ComputeHash()得到的返回值byte[]

希望得到的是

循环将素组中每个元素转换成16进制,保存两位.->buffer[i].ToString("X2"),保存到StringBuilder中

拼接得到的字符串

用ToLower()处理,返回

下面是winform程序中的所有代码,

可以在路径textbox中直接输入路径,判断路径存在?打开改路径:打开默认路径

判断路径中的文件存在?直接计算文件md5值:提示文件不存在,都在leave()中执行

信息textbox中输入字符串,在TextChanged()事件中执行计算MD5方法

比较两个MD5值是否相同,这个简单,注意都转换成大写或小写

注意:空格字符也是内容 "1"的MD5和"1   "不同

using System;using System.Collections.Generic;using System.ComponentModel;using System.Data;using System.Drawing;using System.IO;using System.Linq;using System.Security.Cryptography;using System.Text;using System.Threading.Tasks;using System.Windows.Forms;namespace md5计算器{    public partial class Form1 : Form    {        public Form1()        {            InitializeComponent();        }        private void btnCompare_Click(object sender, EventArgs e)        {            string strMD5 = txtMD.Text.Trim().ToLower();            string strRef = txtReference.Text.Trim().ToLower();            bool b = ResCompare(strMD5,strRef);            string res = b ? "一致" : "MD5值 与 参考值 不相同!";            MessageBox.Show(res);        }        private static bool ResCompare(string strMD5, string strRef)        {            if (strMD5==strRef)            {                return true;            }            return false;        }        private void textBox1_TextChanged(object sender, EventArgs e)        {            String str = txtInfo.Text;            txtMD.Text = GetMD5FromString(str);        }        private static string GetMD5FromString(string str)        {            using (MD5 md=MD5.Create())            {                byte[] strBuffer = Encoding.Default.GetBytes(str);                byte[] mdBuffer = md.ComputeHash(strBuffer);                StringBuilder sbMd5 = new StringBuilder();                for (int i = 0; i < mdBuffer.Length; i++)                {                    sbMd5.Append(mdBuffer[i].ToString("X2"));                }                return sbMd5.ToString().ToLower();            }        }        private void btnChooseFile_Click(object sender, EventArgs e)        {            OpenFileDialog ofd = new OpenFileDialog();            //ofd.InitialDirectory = @"D:\BEI\download\other";            ofd.Filter = "所有文件|*.*|Excel文件(*.xls;*.xlsx)|*.xls;*.xlsx";            ofd.Title = "请选择一个文件";            ofd.Multiselect = false;            if (ofd.ShowDialog()==DialogResult.OK)            {                txtPath.Text = ofd.FileName;                txtMD.Text = GetMd5FromFile(ofd.FileName);            }        }        private void txtPath_TextChanged(object sender, EventArgs e)        {                   }        private static string GetMd5FromFile(string path)        {            using (MD5 md=MD5.Create())            {                using (FileStream fsRead = File.OpenRead(path))                {                    byte[] buffer = md.ComputeHash(fsRead);                    md.Clear();                    StringBuilder sbMD5 = new StringBuilder();                    for (int i = 0; i < buffer.Length; i++)                    {                        sbMD5.Append(buffer[i].ToString("X2"));                    }                    return sbMD5.ToString().ToLower();                }            }        }        private void txtPath_Leave(object sender, EventArgs e)        {                      string path = txtPath.Text;            if (path.Trim()=="")            {                txtMD.Text = "在编辑框中输入字符串 ->自动计算出MD5值";            }            else            {                if (Directory.Exists(path))                {                    OpenFileDialog ofd = new OpenFileDialog();                    ofd.InitialDirectory = path;                    ofd.Filter = "所有文件|*.*|Excel文件(*.xls;*.xlsx)|*.xls;*.xlsx";                    ofd.Title = "请选择一个文件";                    ofd.Multiselect = false;                    if (ofd.ShowDialog() == DialogResult.OK)                    {                        txtPath.Text = ofd.FileName;                        txtMD.Text = GetMd5FromFile(ofd.FileName);                    }                    return;                }                if (File.Exists(path) == true)                {                    txtMD.Text = GetMd5FromFile(path);                }                else                {                    MessageBox.Show("文件不存在");                }            }                   }    }}