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。
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