C#窗体控件与MySQL实现登录功能
1.windows窗体
控件
1 label1
2 label2
3 textBox1
4 textBox2
5 button1
6button2
代码：
using System;
using MySql.Data.MySqlClient;
using System.Windows.Forms;
namespace SQLTest
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
//点击"登录"按钮实现数据库验证登录功能
private void button1_Click(object sender, EventArgs e)
{
//1. 获取数据
//从TextBox中获取用户输入信息
string userName = this.textBox1.Text;
string userPassword = this.textBox2.Text;
//2. 验证数据
// 验证用户输入是否为空，若为空，提示用户信息
if (userName.Equals("") || userPassword.Equals(""))
{
MessageBox.Show("用户名或密码不能为空！");
}
// 若不为空，验证用户名和密码是否与数据库匹配
else
{
//用户名和密码验证正确，提示成功，并执行跳转界面。
/*数据库连接*/
//1.创建数据连接,这里注意你登录数据库的数据库名称，用户名和密码
string strcon = "server=localhost;database=c1test;uid=root;pwd=root;";
MySqlConnection con = new MySqlConnection(strcon);
try
{
//2. 打开数据库
con.Open();
//3. sql语句
string sqlSel = "select count(*) from c1test.users where username = '" + userName + "' and userpwd = '" + userPassword + "'";
MySqlCommand com = new MySqlCommand(sqlSel, con);
//4.判断executeScalar方法返回的参数是否大于0，大于0表示查找有数据
if (Convert.ToInt32(com.ExecuteScalar()) > 0)
{
MessageBox.Show("登录成功！");
//跳转主界面
this.DialogResult = DialogResult.OK;
this.Dispose();
this.Close();
}
//用户名和密码验证错误，提示错误。
else
{
MessageBox.Show("用户名或密码错误！");
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message.ToString() + "打开数据库失败");
}
}
}
}
}
数据库：
database:c1test
table:users
-- ----------------------------
-- Table structure for users
-- ----------------------------
DROP TABLE IF EXISTS `users`;
CREATE TABLE `users` (
`id` int(10) NOT NULL AUTO_INCREMENT,
`username` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
`userpwd` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
`userid` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
`userrole` varchar(20) CHARACTER SET utf8mb4 COLLATE utf8mb4_0900_ai_ci NOT NULL,
PRIMARY KEY (`id`) USING BTREE
) ENGINE = InnoDB CHARACTER SET = utf8mb4 COLLATE = utf8mb4_0900_ai_ci ROW_FORMAT = Dynamic;
-- ----------------------------
-- Records of users
-- ----------------------------
INSERT INTO `users` VALUES (1, 'admin', '123456', '000001', 'adminst');
INSERT INTO `users` VALUES (2, 'Eastmount', 'eastmount', '000002', 'manager');
