using System;
using System.Windows.Forms;
using System.Data.SqlClient;
using System.IO;namespace _8登陆练习操作
{public partial class Form1 : Form{public Form1(){InitializeComponent();}private void SetErrorTimes(){using (SqlConnection conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=E:\MyProjects\C#net传智播客\第五季ADO.NET\8登陆练习操作\8登陆练习操作\Database1.mdf;Integrated Security=True;User Instance=True")){conn.Open();using (SqlCommand upComd = conn.CreateCommand()){upComd.CommandText = "update T_User set ErrorTimes = ErrorTimes + 1 WHERE UserName=@UserName";upComd.Parameters.Add(new SqlParameter("UserName", UserName.Text));upComd.ExecuteNonQuery();}}}private void ResetErrorTimes(){using (SqlConnection conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=E:\MyProjects\C#net传智播客\第五季ADO.NET\8登陆练习操作\8登陆练习操作\Database1.mdf;Integrated Security=True;User Instance=True")){conn.Open();using (SqlCommand updateCmd = conn.CreateCommand()){updateCmd.CommandText = "update T_User set ErrorTimes = 0 WHERE UserName=@UserName";updateCmd.Parameters.Add(new SqlParameter("UserName", UserName.Text));updateCmd.ExecuteNonQuery();}}}private void button1_Click(object sender, EventArgs e){using (SqlConnection conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=E:\MyProjects\C#net传智播客\第五季ADO.NET\8登陆练习操作\8登陆练习操作\Database1.mdf;Integrated Security=True;User Instance=True")){conn.Open();using (SqlCommand cmd = conn.CreateCommand()) {cmd.CommandText = "Select * FROM T_User WHERE UserName=@UserName";cmd.Parameters.Add(new SqlParameter("UserName", UserName.Text));using (SqlDataReader reader = cmd.ExecuteReader()) {if (reader.Read()){int errotTimes = reader.GetInt32(reader.GetOrdinal("ErrorTimes"));if (errotTimes >= 3){//Console.WriteLine("对不起用户已经被锁定!");MessageBox.Show("对不起用户已经被锁定!");}else{string passwd = Password.Text;string t_passwd =reader.GetString(reader.GetOrdinal("Password"));if (passwd == t_passwd){//清空一下ErrorTimes//这里还没有其它的办法，只能另外写一个函数用于来更新ErrorTimes的值/*cmd.Parameters.Clear();cmd.CommandText = "update T_User set ErrorTimes = 0 WERE UserName=@UserName";cmd.Parameters.Add(new SqlParameter("UserName", UserName.Text));cmd.ExecuteNonQuery();* */ResetErrorTimes();MessageBox.Show("登陆成功!");//Console.WriteLine("登陆成功!");}else {//添加ErrorTimes/*cmd.Parameters.Clear(); //这里选清空一下Parameterscmd.CommandText = "update T_User set ErrorTimes = ErrorTimes + 1 WHERE UserName=@UserName";cmd.Parameters.Add(new SqlParameter("UserName",UserName.Text));cmd.ExecuteNonQuery();*///在同一个连接中，如果SqlDataReader没关闭，那么是不能执行Update之类的语句的SetErrorTimes();MessageBox.Show("密码错误!");//Console.WriteLine("密码错误!");}}}else {//Console.WriteLine("用户名不存在!");MessageBox.Show("用户名不存在!");}}}}}//文件导入private void button2_Click(object sender, EventArgs e){//当点击弹出窗口，然后点击了确定if (openFileDialog1.ShowDialog() == DialogResult.OK) {//取得文件流using (FileStream fileStream = File.OpenRead(openFileDialog1.FileName)) {//读取文件using (StreamReader streamReader = new StreamReader(fileStream)) {string line = null;while ((line = streamReader.ReadLine()) != null) {string[] str = line.Split('|');string name = str[0];string passwd = str[1];int errorTimes = Convert.ToInt32(str[2]);using (SqlConnection conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=E:\MyProjects\C#net传智播客\第五季ADO.NET\8登陆练习操作\8登陆练习操作\Database1.mdf;Integrated Security=True;User Instance=True")){conn.Open();using (SqlCommand cmd = conn.CreateCommand()){//MessageBox.Show("name:"+name+",passwd:"+passwd+",errorTimes:"+errorTimes+"");//在这里测试了一会儿，唉，自己不小心，把变量给写错了，看来以后还要多加小心才行cmd.CommandText = "Insert into T_User(UserName, Password, ErrorTimes) values(@username,@password,@errortimes) ";cmd.Parameters.Add(new SqlParameter("username", name));cmd.Parameters.Add(new SqlParameter("password", passwd));cmd.Parameters.Add(new SqlParameter("errortimes", errorTimes));cmd.ExecuteNonQuery();}                            }}}}}MessageBox.Show("导入成功!");}//文件导出private void button3_Click(object sender, EventArgs e){using (SqlConnection conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=E:\MyProjects\C#net传智播客\第五季ADO.NET\8登陆练习操作\8登陆练习操作\Database1.mdf;Integrated Security=True;User Instance=True")){conn.Open();using (SqlCommand cmd = conn.CreateCommand()){cmd.CommandText = "select * FROM T_User";//读取多行数据using (SqlDataReader reader = cmd.ExecuteReader()){StreamWriter sw = File.CreateText(@"c:\2.txt");while (reader.Read()) //循环数据{long id = reader.GetInt64(reader.GetOrdinal("Id"));string name = reader.GetString(reader.GetOrdinal("UserName"));string passwd = reader.GetString(reader.GetOrdinal("Password"));int errortimes = reader.GetInt32(reader.GetOrdinal("ErrorTimes"));sw.WriteLine("{0}|{1}|{2}|{3}",id,name,passwd,errortimes);//MessageBox.Show("id:" + id + ",name:" + name + ",passwd:" + passwd + ",errortimes:" + errortimes);}sw.Close();}}}MessageBox.Show("导出数据成功!");}/*省市选择程序，数据全部来自于数据库:http://www.programfan.com/blog/article.asp?id=28128* 把createtable中的varchar改为nvarchar,在insert语句的汉字前面加上N(查找","替换为".N")我不做好像也没事* ComboBox的显示值，Items.Add的参数是Object类型，也就是可以放任意数据类型的数据* 可以设置DisplayMember属性设定显示的属性，通过SelectItem属性取得到就是选择的条目对应的对像，例子* 疑问: 取出来的是Object,怎么能转换为对应的类型?变量名只是"标签".显示的值和实际的对像不一样，在ASP.Net中也有相同的东西* 创建一个ProvinceItem类，将数据填充在这个对像中添加到ComBoBox中* **/private void Form1_Load(object sender, EventArgs e){//MessageBox.Show("一进入就开始加载省份信息!");//设定comboBox的DisplayMember属性为name,就会显示对像的Name属性的值/*cb_city.DisplayMember = "Name";ProvinceItem item = new ProvinceItem();item.Id = 1;item.Name = "北京";cb_city.Items.Add(item);ProvinceItem item2 = new ProvinceItem();item2.Id = 2;item2.Name = "上海";cb_city.Items.Add(item2);*/using (SqlConnection conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=E:\MyProjects\C#net传智播客\第五季ADO.NET\8登陆练习操作\8登陆练习操作\Database1.mdf;Integrated Security=True;User Instance=True")){conn.Open();using (SqlCommand cmd = conn.CreateCommand()) {cmd.CommandText = "select * FROM promary ";cb_city.DisplayMember = "Name";using (SqlDataReader reader = cmd.ExecuteReader()) {while (reader.Read()) {int proid = reader.GetInt32(reader.GetOrdinal("proID"));string proName = reader.GetString(reader.GetOrdinal("proName"));ProvinceItem item = new ProvinceItem();item.Id = proid;item.Name = proName;cb_city.Items.Add(item);}}}}}private void cb_city_SelectedIndexChanged(object sender, EventArgs e){/*string text = cb_city.SelectedText;int index = cb_city.SelectedIndex;//string value = cb_city.SelectedValue;string item = cb_city.SelectedItem.ToString();MessageBox.Show("item=" + item);*/ProvinceItem item = (ProvinceItem)cb_city.SelectedItem;int proId = item.Id;string name = item.Name;//MessageBox.Show("proId:"+proId+",name:"+name);using (SqlConnection conn = new SqlConnection(@"Data Source=.\SQLEXPRESS;AttachDbFilename=E:\MyProjects\C#net传智播客\第五季ADO.NET\8登陆练习操作\8登陆练习操作\Database1.mdf;Integrated Security=True;User Instance=True")){conn.Open();using (SqlCommand cmd = conn.CreateCommand()) {cmd.CommandText = "select * FROM city WHERE proID="+proId;using (SqlDataReader reader = cmd.ExecuteReader()) {cb_city_small.Items.Clear();cb_city_small.SelectedIndex = -1;cb_city_small.DisplayMember = "Name";while (reader.Read()) {ProvinceItem city = new ProvinceItem();int cityID = reader.GetInt32(reader.GetOrdinal("cityID"));string cityName = reader.GetString(reader.GetOrdinal("cityName"));city.Id = cityID;city.Name = cityName;cb_city_small.Items.Add(city);}}}}}}class ProvinceItem {public string Name { get; set; }public int Id { get; set; }}
}