文件名称：登录有数据库连接窗口
文件大小：908B
文件格式：SLN
更新时间：2015-01-05 05:44:29
有数据库连接
很简单！刚学的！有登录和注册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 WindowsFormsApplication2 { public partial class Form1 : Form { SqlConnection conn = null; public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { try{ SqlCommand com = conn.CreateCommand(); string users = textBox1.Text; string password = textBox2.Text; com.CommandText = "select * from T_login where LOGIN_user='"+users+"'"; SqlDataReader reader = com.ExecuteReader(); if (reader.Read()) { //用户名正确！ string dbpassword = reader.GetString(reader.GetOrdinal("LOGIN_password")); if (password == dbpassword) { MessageBox.Show("登陆成功！"); } else { MessageBox.Show("密码错误！"); } } else { MessageBox.Show("用户名错误！"); } reader.Close(); } catch(Exception ex) { MessageBox.Show(ex.Message); } } private void Form1_Load(object sender, EventArgs e) { string connString = @"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\Database1.mdf;Integrated Security=True;User Instance=True"; try { conn = new SqlConnection(connString); conn.Open(); MessageBox.Show("成功！"); } catch (Exception ex) { MessageBox.Show(ex.Message); } } private void Form1_FormClosing(object sender, FormClosingEventArgs e) { conn.Dispose(); } private void button3_Click(object sender, EventArgs e) { try { SqlCommand com = conn.CreateCommand(); string users = textBox1.Text; string password = textBox2.Text; com.CommandText = "select * from T_login"; SqlDataReader reader = com.ExecuteReader(); label3.Text = "id,用户名，密码\n"; while (reader.Read()) { label3.Text = label3.Text +"\n"+ string.Format("{0},{1},{2}", reader[0], reader[1], reader[2]); } reader.Close(); } catch (Exception ex) { MessageBox.Show(ex.Message); } } private void button2_Click(object sender, EventArgs e) { try { SqlCommand com = conn.CreateCommand(); string users = textBox1.Text; string password = textBox2.Text; com.CommandText = "select * from T_login where LOGIN_user='" + users + "'"; SqlDataReader reader = com.ExecuteReader(); if (reader.Read()) { //用户名存在！ MessageBox.Show("用户名已经存在"); reader.Close(); } else { reader.Close(); //可以注册 com.CommandText = "INSERT INTO T_login (LOGIN_user, LOGIN_password) VALUES ('"+users+"', '"+password+"')"; com.ExecuteNonQuery(); MessageBox.Show("注册成功！"); } } catch (Exception ex) { MessageBox.Show(ex.Message); } } } }