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Parameters
cmd.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; }
}
}