C#+winform登陆界面案例
这俩天做登陆界面设计，也在网上查了一些资料，发现大部分都是针对某个功能介绍，而很少有完整的案列。我呢就结合自己的需求，把有些功能整合在一起了，欢迎大家修改完善。
SQL数据库设计：
登陆界面设计：
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 ZH_controls
{
public partial class Login : Form
{
public Login()
{
InitializeComponent();
}
private void Login_Load(object sender, EventArgs e)
{
}
private void Login_Button_Click(object sender, EventArgs e) //单击登陆按钮
{
String username, password;
username = UserName.Text;
password = Password.Text;
String myconn = "Data Source=PC-20180112FRNM;Initial Catalog=属性表;User ID=sa;Password=123;Integrated Security=True";//数据库实例连接字符串
SqlConnection sqlConnection = new SqlConnection(myconn);//新建数据库连接实例
sqlConnection.Open();//打开数据库连接
password = Adduser.GetMD5(password); //在同一个命名空间（在同一个文件夹中），可以访问Adduser里的GetMD5函数。 因为MD5加密算法不可逆，所以要把输入的密码加密和数据库里密码匹配。这样做以后，除了用户自己谁也不知道密码了。
String sql = "select UserName,Password from User_info where UserName='" + username + "'and Password='" + password + "'";//SQL语句实现表数据的读取
SqlCommand sqlCommand = new SqlCommand(sql, sqlConnection);
SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
if (UserName.Text == "")
{
MessageBox.Show("请输入用户名", "登陆失败");
UserName.Focus();
}
else if (Password.Text == "")
{
MessageBox.Show("请输入密码", "登陆失败");
}
else
{
if (sqlDataReader.HasRows)//满足用户名与密码一致，进入下一个界面
{
//实现页面跳转
Form1 form3 = new Form1();
this.Hide(); //隐藏当前窗体
form3.ShowDialog();
Application.ExitThread(); //退出当前窗体，这一步很重要，否则最后可能无法将所有进程关闭。最好是在跳转页面后，将之前的页面退出。
}
else//如果登录失败，询问是否注册新用户
{
DialogResult dr = MessageBox.Show("是否注册新用户？", "登录失败", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
if (dr == DialogResult.Yes)//打开注册界面
{
Adduser form2 = new Adduser();
this.Hide();
form2.ShowDialog();
Application.ExitThread();
}
else
{
UserName.Text = "";
Password.Text = "";
UserName.Focus();
this.Show();
}
}
}
sqlConnection.Close();
}
private void Register_Click(object sender, EventArgs e) //单击注册按钮
{
Adduser form2 = new Adduser();
this.Hide();
form2.ShowDialog();
Application.ExitThread();
}
private void Quit_Click(object sender, EventArgs e) //单击退出按钮
{
Application.Exit();
}
private void UserName_KeyPress(object sender, KeyPressEventArgs e) //功能：输入用户名后，按 Enter键，光标到输入密码的TextBox中
{
if (e.KeyChar == (char)Keys.Enter)
{
Password.Focus(); //控制光标指向哪的
}
}
private void Password_KeyPress(object sender, KeyPressEventArgs e) //KeyPress事件，在控件具有焦点并且用户按下并释放某个键后发生
{
if (e.KeyChar == (char)Keys.Enter)
{
// Login_Button.Focus();
Login_Button_Click(sender ,e);
}
}
}
}
注册页面设计：
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;
using System.Security.Cryptography; //MD5密码加密
namespace ZH_controls
{
public partial class Adduser : Form
{
public Adduser()
{
InitializeComponent();
}
private void button1_Click(object sender, EventArgs e) //单击确定按钮
{
String username, password, repassword;
username = textBox1.Text;
password = textBox2.Text;
repassword = textBox3.Text;
if (textBox1.Text == "")
{
MessageBox.Show("请输入用户名", "注册失败");
textBox1.Focus();
}
else if (textBox2.Text == "")
{
MessageBox.Show("请输入密码", "注册失败");
textBox2.Focus();
}
else if (textBox3.Text == "")
MessageBox.Show("请确认密码", "注册失败");
else
{
string myConn = "Data Source=PC-20180112FRNM;Initial Catalog=属性表;User ID=sa;Password=123;Integrated Security=True";
SqlConnection sqlConnection = new SqlConnection(myConn); //实例化连接对象
sqlConnection.Open();
String sql = "select UserName from User_info where UserName='" + username + "'";//SQL语句实现表数据的读取
SqlCommand sqlCommand = new SqlCommand(sql, sqlConnection);
SqlDataReader sqlDataReader = sqlCommand.ExecuteReader();
if (sqlDataReader.HasRows)
{
sqlConnection.Close();
MessageBox.Show("该用户名已存在，请重新注册", "注册失败");
textBox1.Text = "";
textBox2.Text = "";
textBox3.Text = "";
textBox1.Focus(); //指定光标在哪个textBox处闪烁
}
else
{
if (password == repassword)//两次输入的密码一致
{
sqlConnection.Close();
string myConn2 = "Data Source=PC-20180112FRNM;Initial Catalog=属性表;User ID=sa;Password=123;Integrated Security=True";
SqlConnection sqlConnection2 = new SqlConnection(myConn2); //实例化连接对象
sqlConnection.Open();
password = GetMD5(password);
String sql2 = "INSERT INTO User_info(UserName,Password) VALUES('" + username + "','" + password + "')";//SQL语句向表中写入数据
SqlCommand sqlCommand2 = new SqlCommand(sql2, sqlConnection);
sqlCommand2.ExecuteNonQuery();
sqlConnection2.Close();
DialogResult dr = MessageBox.Show("是否返回主界面", "注册成功", MessageBoxButtons.YesNo, MessageBoxIcon.Question);
if (dr == DialogResult.Yes)//打开注册界面
{
Login form2 = new Login();
this.Hide();
form2.ShowDialog();
Application.ExitThread();
}
else
{
textBox1.Text = "";
textBox2.Text = "";
textBox3.Text = "";
this.Show();
}
}
else
{
MessageBox.Show("两次输入密码不一致", "错误信息");
textBox1.Text = "";
textBox2.Text = "";
textBox3.Text = "";
}
}
}
}
private void button2_Click(object sender, EventArgs e) //返回登陆按钮
{
Login form3 = new Login();
this.Hide();
form3.ShowDialog();
Application.ExitThread();
}
public static string GetMD5(String input) //MD5算法，输入一段字符串，输出一段字符串
{
string cl = input;
string pwd = "";
MD5 md5 = MD5.Create();//实例化一个md5对像
// 加密后是一个字节类型的数组，这里要注意编码UTF8/Unicode等的选择
byte[] s = md5.ComputeHash(Encoding.UTF8.GetBytes(cl));
// 通过使用循环，将字节类型的数组转换为字符串，此字符串是常规字符格式化所得
for (int i = 0; i < s.Length; i++)
{
// 将得到的字符串使用十六进制类型格式。格式后的字符是小写的字母，如果使用大写（X）则格式后的字符是大写字符
pwd = pwd + s[i].ToString("X");
}
return pwd;
}
private void textBox1_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == (char)Keys.Enter)
{
textBox2.Focus();
}
}
private void textBox2_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == (char)Keys.Enter)
{
textBox3.Focus();
}
}
private void textBox3_KeyPress(object sender, KeyPressEventArgs e)
{
if (e.KeyChar == (char)Keys.Enter)
{
button1_Click(null, null);
}
}
}
}