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。
