private void button1_Click(object sender, EventArgs e)
{
shangping s = new shangping();
s.Show();
this.Close();
}
private void button1_Click(object sender, EventArgs e)
{
using (SqlConnection conn = new SqlConnection(connectionString))
{
conn.Open();
//打开数据库的连接
String sql = "select * from users where user_id = @user_id and user_psw = @user_psw ";
//创建数据库的操作字符串
SqlCommand cmd = new SqlCommand(sql, conn);
//对指定的对象，操作字符串内容
cmd.Parameters.Add(new SqlParameter("@user_id", textBox1.Text));
//用参数代替占位符，线性更安全
cmd.Parameters.Add(new SqlParameter("@user_psw", textBox2.Text));
SqlDataReader reader = cmd.ExecuteReader();//操作
if (reader.Read())
{
//如果查询到内容，跳转到Information界面，同时关闭当前界面
shangping sp = new shangping();
sp.Show();
this.Hide();
}
else
{
//MessageBox.Show("请输入正确信息！");
//textBox1.Text = "";
//textBox2.Text = "";
main m = new main();
m.Show();
this.Hide();
}
}
}