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public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
this.Opacity = 1;
}
//登陆
private void button1_Click(object sender, EventArgs e)
{
/*
点击button后验证用户名与密码的权限,弹出新的form并隐藏当前form*/
string user;
string password;
user = textBox1.Text;
password = textBox2.Text;
string connect = "Database=test;server=localhost;User Id=root;Password=root;";
MySqlConnection conn = new MySqlConnection(connect);
string selectquery = "select count(*)from user where username='" + user + "' and password='" + password + "'";
MySqlCommand cmd = new MySqlCommand(selectquery, conn);
try
{
conn.Open();
}
catch (MySqlException ex)
{
switch (ex.Number)
{
case 0:
MessageBox.Show("无法连接到服务器,请联系管理员"); break;
case 1045:
MessageBox.Show("服务器用户名/密码错误, 请确认数据库信息或联系管理员"); break;
}
}
int b = 0;
b = Convert.ToInt32(cmd.ExecuteScalar());
if (b == 1) //ExecuteNonQuery只适用于update insert delete,返回的是受影响的行数
{
this.Opacity = 0;
Form2 frm = new Form2();//首先实例化
frm.Show();//Show方法
}
else MessageBox.Show("用户名/密码错误!");
conn.Close();
}
//退出按钮
private void button2_Click(object sender, EventArgs e)
{
Application.Exit();
}
}
这是我写的登陆界面,也是连接mysql,从表中检索用户登陆信息的,供参考