C#结合数据库实现验证识别ID卡内容的方法

本文所述实例为C#结合数据库，来验证所识别的ID卡内容，通过本实例代码，用户可以轻松实现对ID卡会员信息的验证。该实例代码可实现读取数据库，进而逐步实现数据库连接，数据库读取，ID卡读取，ID卡信息与数据库内容比对，最终返回结果并告之是否验证成功。

具体功能代码如下：

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;
using System.Runtime.InteropServices;
using System.Diagnostics;
using System.Collections;
namespace IDCard
{
  public partial class Form1 : Form
  {
    public Form1()
    {
      InitializeComponent();
    }
    public delegate int HookProc(int nCode, int wParam, IntPtr lParam);
    static int hHook = 0;
    public const int WH_KEYBOARD_LL = 13;
    //LowLevel键盘截获，如果是WH_KEYBOARD＝2，并不能对系统键盘截取，Acrobat Reader会在你截取之前获得键盘。 
    HookProc KeyBoardHookProcedure;
    [Dllimport("kernel32")]
    public static extern int Beep(int dwFreq, int dwDuration);//让计算机蜂鸣
    string DataPath = "";//数据库路径
    OleDbConnection con;//OleDbConnection对象，连接数据库
    OleDbCommand cmd;//OleDbCommand对象，执行SQL语句
    //键盘Hook结构函数 
    [StructLayout(LayoutKind.Sequential)]
    public class KeyBoardHookStruct
    {
      public int vkCode;
      public int scanCode;
      public int flags;
      public int time;
      public int dwExtraInfo;
    }
    [Dllimport("user32.dll")]
    public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, IntPtr hInstance, int threadId);
    [Dllimport("user32.dll", CharSet = CharSet.Auto, CallingConvention = CallingConvention.StdCall)]
    //抽掉钩子 
    public static extern bool UnhookWindowsHookEx(int idHook);
    [Dllimport("user32.dll")]
    //调用下一个钩子 
    public static extern int CallNextHookEx(int idHook, int nCode, int wParam, IntPtr lParam);
    [Dllimport("kernel32.dll")]
    public static extern IntPtr GetModuleHandle(string name);

    public string getNum(string code)
    {
      string flag = "";
      switch (code)
      {
 case "048":
   flag="0"; break;
 case "049":
   flag = "1"; break;
 case "050":
   flag = "2"; break;
 case "051":
   flag = "3"; break;
 case "052":
   flag = "4"; break;
 case "053":
   flag = "5"; break;
 case "054":
   flag = "6"; break;
 case "055":
   flag = "7"; break;
 case "056":
   flag = "8"; break;
 case "057":
   flag = "9"; break;
      }
      return flag;
    }
    public void Hook_Start()
    {

      // 安装键盘钩子 
      if (hHook == 0)
      {
 KeyBoardHookProcedure = new HookProc(KeyBoardHookProc);
 hHook = SetWindowsHookEx(WH_KEYBOARD_LL,
      KeyBoardHookProcedure,
     GetModuleHandle(Process.GetCurrentProcess().MainModule.ModuleName), 0);
 //如果设置钩子失败. 
 if (hHook == 0)
 {
   Hook_Clear(); 
 }
      }
    }

    //取消钩子事件 
    public void Hook_Clear()
    {
      bool retKeyboard = true;
      if (hHook != 0)
      {
 retKeyboard = UnhookWindowsHookEx(hHook);
 hHook = 0;
      }
      //如果去掉钩子失败. 
      if (!retKeyboard) throw new Exception("UnhookWindowsHookEx failed.");
    }

    //这里可以添加自己想要的信息处理 
    string NumCode="";
    public int KeyBoardHookProc(int nCode, int wParam, IntPtr lParam)
    {
      if (nCode >= 0)
      {
 if (wParam == 0x0104 || wParam == 0x0100)
 {
   KeyBoardHookStruct kbh = (KeyBoardHookStruct)Marshal.PtrToStructure(lParam, typeof(KeyBoardHookStruct));
   int flag = kbh.vkCode;
   switch (flag)
   {
     case 96:
NumCode += "0"; break;
     case 97:
NumCode += "1"; break;
     case 98:
NumCode += "2"; break;
     case 99:
NumCode += "3"; break;
     case 100:
NumCode += "4"; break;
     case 101:
NumCode += "5"; break;
     case 102:
NumCode += "6"; break;
     case 103:
NumCode += "7"; break;
     case 104:
NumCode += "8"; break;
     case 105:
NumCode += "9"; break;
   }

   if (flag == 13)
   {
     if (NumCode.Length != 0)
     {
string c = "";
string id = "";
for (int i = 0; i <= NumCode.Length - 3; i += 3)
{
  string b = NumCode.Substring(i, 3);
  c += getNum(b);
}
id = c;
if (id.Length == 8)//如果卡号为8位
{
  //实例化OleDbConnection对象
  con = new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data source=" + DataPath);
  con.Open();//打开数据库连接
  //实例化OleDbCommand对象，根据ID卡号检索数据表
  cmd = new OleDbCommand("select * from tb_UserInfo where CardID='" + id + "'", con);
  OleDbDataReader sdr = cmd.ExecuteReader();//实例化OleDbDataReader对象
  sdr.Read();//读取记录
  txtShowCardID.Text = id;//获取ID卡号
  txtShowName.Text = sdr["UName"].ToString();//获取员工姓名
  cbbShowSex.Text = sdr["USex"].ToString();//获取员工性别
  cbbShowDep.Text = sdr["UDep"].ToString();//获取员工部门
  con.Close();//关闭数据库连接
  Beep(3000, 100);//计算机蜂鸣
}
NumCode = "";
     }
   }

 }
      }
      return CallNextHookEx(hHook, nCode, wParam, lParam);
    } 



    private void Form1_Load(object sender, EventArgs e)
    {
      cbbdep.SelectedIndex = 0;//设置部门下拉框的第一项被选中
      cbbsex.SelectedIndex = 0;//设置性别下拉框的第一项被选中
      //获取数据库路径
      DataPath = Application.StartupPath.ToString();
      DataPath = DataPath.Substring(0, DataPath.LastIndexOf("\"));
      DataPath = DataPath.Substring(0, DataPath.LastIndexOf("\"));
      DataPath += @"db.mdb";
      
    }

    private void radioButton1_CheckedChanged(object sender, EventArgs e)
    {
      if (radioButton1.Checked)
      {
 groupBox1.Enabled = true;
 Hook_Clear();
      }
    }

    private void radioButton2_CheckedChanged(object sender, EventArgs e)
    {
      if (radioButton2.Checked)
      {
 groupBox1.Enabled = false;
 Hook_Start();
      }
    }

    private void button2_Click(object sender, EventArgs e)
    {
      txtIdcard.Text = "";
      txtName.Text = "";
    }

    private void button1_Click(object sender, EventArgs e)
    {
      if (txtIdcard.Text == "" || txtName.Text == "")//如果没有输入ID卡号和员工姓名
      {
 //弹出警告信息
 if (MessageBox.Show("请将数据填写完整！", "警告", MessageBoxButtons.OK, MessageBoxIcon.Error) == DialogResult.OK)
 {
   if (txtIdcard.Text == "")//如果没有输入ID卡号
     txtIdcard.Focus();//则光标处在输入ID卡号的文本框
   if (txtName.Text == "")//如果没有输入员工姓名
     txtName.Focus();//则光标处在输入员工姓名的文本框
   if (txtIdcard.Text == "" && txtName.Text == "")//如果都没输入数据
     txtIdcard.Focus();//则光标处在输入ID卡号的文本框
 }
      }
      else//如果输入了数据
      {
 if (txtIdcard.Text.Trim().Length != 8)//如果输入的ID卡号不是8位
 {
   //弹出警告信息
   if (MessageBox.Show("ID卡号必须为8位！", "警告", MessageBoxButtons.OK, MessageBoxIcon.Error) == DialogResult.OK)
   {
     txtIdcard.Text = "";//清空输入ID卡号的文本框
     txtIdcard.Focus();//让光标处在输入ID卡号的文本框上
   }
 }
 else//如果输入的ID卡号为8位
 {
   //实例化OleDbConnection对象
   con=new OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data source=" + DataPath);
   con.Open();//打开连接
   //实例化OleDbCommand对象
   cmd = new OleDbCommand("select count(*) from tb_UserInfo where CardID='"+txtIdcard.Text.Trim()+"'", con);
   int flag =Convert.ToInt32(cmd.ExecuteScalar());//判断是否已经添加过此ID卡号
   if (flag > 0)//如果大于0则说明已经添加过
   {
     //弹出警告信息
     if (MessageBox.Show("ID卡号已经添加过了！", "警告", MessageBoxButtons.OK, MessageBoxIcon.Error) == DialogResult.OK)
     {
button2_Click(sender, e);//清空输入ID卡号和员工姓名的文本框
     }
   }
   else//如果小于0说明没有添加过
   {
     //实例化OleDbCommand对象
     cmd = new OleDbCommand("insert into tb_UserInfo(CardID,UName,USex,UDep) values ('" + txtIdcard.Text.Trim() + "','" + txtName.Text.Trim() + "','" + cbbsex.Text.Trim() + "','" + cbbdep.Text.Trim() + "')", con);
     int k = cmd.ExecuteNonQuery();//执行insert语句，将输入的信息添加到数据库中
     if (k > 0)//如果大于0则操作成功
     {
//弹出提示信息
if (MessageBox.Show("添加成功！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Information) == DialogResult.OK)
{
  button2_Click(sender, e);//清空输入ID卡号和员工姓名的文本框
}
     }
   }
   con.Close();//关闭数据库连接
 }
      }
    }

    private void txtIdcard_KeyPress(object sender, KeyPressEventArgs e)
    {
      if (!(e.KeyChar <= '9' && e.KeyChar >= '0') && e.KeyChar != 'r' && e.KeyChar != 'b')
      {
 e.Handled = true;
      }
    }
  }
}

该实例注释完善，便于阅读，读者还可以根据自身需求改善代码，或者添加新的功能以满足自身应用的个性化需求。