C#_连接数据库实现 登录注册界面
时间:2021-07-01 10:21:17
帮助过:9人阅读
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;
using System.Data.SqlClient;
namespace LoginDatabase
{
public partial class Login : Form
{
private int errorTime =
3;
public Login() {
InitializeComponent();
}
private void loginBtn_Click(
object sender, EventArgs e) {
errorTime = errorTime -
1;
string username = txtName.Text.Trim();
//取出账号
string pw = txtPwd.Text.Trim();
//取出密码
string constr =
"Server=.;DataBase=SU; Integrated Security=True";
//设置连接字符串
SqlConnection mycon =
new SqlConnection(constr);
//实例化连接对象
mycon.Open();
SqlCommand mycom = mycon.CreateCommand();
//创建SQL命令执行对象
string s1 =
"select account,password from register where account=‘" + username +
"‘ and password=‘" + pw +
"‘";
//编写SQL命令
mycom.CommandText = s1;
//执行SQL命令
SqlDataAdapter myDA =
new SqlDataAdapter();
//实例化数据适配器
myDA.SelectCommand = mycom;
//让适配器执行SELECT命令
DataSet myDS =
new DataSet();
//实例化结果数据集
int n = myDA.Fill(myDS,
"register");
//将结果放入数据适配器,返回元祖个数
if (n !=
0) {
if (checkCode.Text ==
textCheck.Text) {
MessageBox.Show("欢迎使用!");
//登录成功
this.Close();
} else {
MessageBox.Show("验证码填写错误");
textCheck.Text =
"";
}
} else
if (errorTime <
3) {
MessageBox.Show("用户名或密码有错。请重新输入!还有" + errorTime.ToString() +
"次机会");
txtName.Text =
"";
//清空账号
txtPwd.Text =
"";
//清空密码?
txtName.Focus();
//光标设置在账号上
}
else {
MessageBox.Show("你输入的用户名或密码已达三次? 将退出程序");
this.Close();
}
}
private void cancelBtn_Click(
object sender, EventArgs e) {
Application.Exit();
}
private void button1_Click(
object sender, EventArgs e) {
Register register =
new Register();
register.ShowDialog();
}
private void checkCode_Click(
object sender, EventArgs e) {
Random random =
new Random();
int minV =
12345, maxV =
98765;
checkCode.Text =
random.Next(minV, maxV).ToString();
}
}
}
5.编写注册界面逻辑
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Data.SqlClient;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Windows.Forms;
namespace LoginDatabase
{
public partial class Register : Form
{
public Register() {
InitializeComponent();
}
private void btnRegister_Click(
object sender, EventArgs e) {
//检查是否已经存在
string userID = userId.Text.Trim();
//取出账号
/**
* 连接数据库
*/
string constr =
"Server=.;DataBase=SU; Integrated Security=True";
//设置连接字符串
SqlConnection mycon =
new SqlConnection(constr);
//实例化连接对象
mycon.Open();
//查询新注册的用户是否存在
SqlCommand checkCmd = mycon.CreateCommand();
//创建SQL命令执行对象
string s =
"select account from register where account=‘" + userID +
"‘";
checkCmd.CommandText =
s;
SqlDataAdapter check =
new SqlDataAdapter();
//实例化数据适配器
check.SelectCommand = checkCmd;
//让适配器执行SELECT命令
DataSet checkData =
new DataSet();
//实例化结果数据集
int n = check.Fill(checkData,
"register");
//将结果放入数据适配器,返回元祖个数
if (n !=
0) {
MessageBox.Show("用户名存在");
userId.Text =
""; userPw.Text =
"";
nickName.Text =
"";
}
//确认密码
if (ensurePw.Text !=
userPw.Text) {
ensurePw.Text =
"";
}
//验证码
if (textCheck.Text !=
checkCode.Text) {
textCheck.Text =
"";
}
//插入数据SQL 逻辑
string s1 =
"insert into Register(account,password,nickname) values (‘" + userId.Text +
"‘,‘" + userPw.Text +
"‘,‘"
+ nickName.Text +
"‘)";
//编写SQL命令
SqlCommand mycom =
new SqlCommand(s1, mycon);
//初始化命令
mycom.ExecuteNonQuery();
//执行语句
mycon.Close();
//关闭连接
mycom =
null;
mycon.Dispose(); //释放对象
if (userId.Text ==
"" || userPw.TextLength <=
6 || nickName.Text ==
"" || ensurePw.Text ==
""
|| textCheck.Text ==
"") {
MessageBox.Show("请将信息填完整");
} else {
MessageBox.Show("注册成功");
this.Close();
}
}
private void checkCode_Click(
object sender, EventArgs e) {
Random random =
new Random();
int minV =
12345, maxV =
98765;
checkCode.Text =
random.Next(minV, maxV).ToString();
}
}
C#_连接数据库实现 登录注册界面
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