Question

C#应用程序登陆界面如何连接到SQL数据库验证用户名和用户密码，我要详细代码和详细注释……

Answer 1

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.SqlClient;

namespace MyKtv
{
public partial class FrmLogin : Form
{
public static string UserName;
public static string UserPwd;

public FrmLogin()
{
InitializeComponent();
}

private void btnclear_Click(object sender, EventArgs e)
{
DialogResult result = MessageBox.Show("是否要退出？？", "温馨提示", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
if (result == DialogResult.Yes)
{
this.Close();

}
}

private void btnlogin_Click(object sender, EventArgs e)
{
CheckUser();
}
public void CheckUser()
{
UserName = txtname.Text;
UserPwd = txtpwd.Text;

if (UserName.Trim() == "")
{
MessageBox.Show("请输入用户名");
this.txtname.Focus();
}
else if (UserPwd.Trim() == "")
{
MessageBox.Show("请输入密码");
this.txtname.Focus();
}
else
{
string sql = string.Format("select count(*) from admin_info where admin_name='{0}' and admin_pwd='{1}'", UserName, UserPwd);
try
{
DBHepler.con.Open();
SqlCommand com = new SqlCommand(sql, DBHepler.con);
int i = (int)com.ExecuteScalar();
if (i > 0)

{
FrmAdmin admin = new FrmAdmin();
admin.Show();
this.Hide();

}
else
{
MessageBox.Show("用户名或密码错误！请重新输入！");
}

}
catch (Exception e)
{

MessageBox.Show(e.Message);
}
finally
{
DBHepler.con.Close();
}
}
}

private void FrmLogin_Load(object sender, EventArgs e)
{

}

}
}

Answer 2

有比这个更简单的么?我的思路跟上面的一样，执行完查询语句后，返回一个标识，判断如果>0就登录成功，否则登录失败！