QQ登录窗口 示例源码(sql server数据库)

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 WindowsFormsApplication1{ public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { string connstr = "server=.\\sql2005;database=mytest; uid=sa;pwd=sa"; using (SqlConnection conn = new SqlConnection(connstr)) { SqlCommand cmd = new SqlCommand(); string sqlstr = "select * from user_login where username='" textBox1.Text "'"; cmd.Connection = conn; cmd.CommandText = sqlstr; conn.Open(); SqlDataReader dr = cmd.ExecuteReader(); if (dr.Read()) { if(textBox2 .Text ==(string)dr["password"]) { MessageBox.Show("登录成功"); this.DialogResult = DialogResult.OK; //Form2 f2 = new Form2(); //this.Hide(); //f2.username =(string)dr["username"]; //f2.Show(); } else { MessageBox.Show("密码错误"); } } else { MessageBox.Show("用户名错误"); } } } }}