文章的目的为了记录使用C# 开发学习的经历。开发流程和要点有些记忆模糊，赶紧记录，防止忘记。
相关链接：
开源 C# 快速开发（十六）数据库--sqlserver增删改查
推荐链接:
开源 C# .net mvc 开发（一）WEB搭建_c#部署web程序-CSDN博客
开源 C# .net mvc 开发（二）网站快速搭建_c#网站开发-CSDN博客
开源 C# .net mvc 开发（三）WEB内外网访问-CSDN博客
开源 C# .net mvc 开发（四）工程结构、页面提交以及显示-CSDN博客
开源 C# .net mvc 开发（五）常用代码快速开发_c# mvc开发-CSDN博客
开源 C# .net mvc 开发（六）发送邮件、定时以及CMD编程-CSDN博客
开源 C# .net mvc 开发（七）动态图片、动态表格和json数据生成-CSDN博客
开源 C# .net mvc 开发（八）IIS Express轻量化Web服务器的配置和使用-CSDN博客
开源 C# .net mvc 开发（九）websocket--服务器与客户端的实时通信-CSDN博客
本章节主要内容是:C#对sqlserver数据库，进行增删改查的例子。
目录：
1.源码分析
2.所有源码
3.效果演示
一、源码分析
- CreateUserTableIfNotExists() 函数
功能：检查并创建用户表
具体实现：
使用 sysobjects 系统表检查 'user' 表是否存在
如果不存在则创建包含以下字段的表：
Id：自增主键（IDENTITY(1,1)）
Username：唯一用户名，NVARCHAR(50)，非空
Password：密码，NVARCHAR(100)，非空
Email：邮箱，NVARCHAR(100)，可为空
CreatedDate：创建时间，DATETIME，默认当前时间
LastLogin：最后登录时间，DATETIME，可为空
IsActive：激活状态，BIT，默认激活
执行成功后输出创建成功消息
public void CreateUserTableIfNotExists()
{
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
string createTableSql = @"
IF NOT EXISTS (SELECT * FROM sysobjects WHERE name='user' AND xtype='U')
BEGIN
CREATE TABLE [user] (
Id INT IDENTITY(1,1) PRIMARY KEY,
Username NVARCHAR(50) NOT NULL UNIQUE,
Password NVARCHAR(100) NOT NULL,
Email NVARCHAR(100),
CreatedDate DATETIME NOT NULL DEFAULT GETDATE(),
LastLogin DATETIME NULL,
IsActive BIT NOT NULL DEFAULT 1
)
PRINT 'User表创建成功！'
END";
using (SqlCommand command = new SqlCommand(createTableSql, connection))
{
command.ExecuteNonQuery();
}
}
}
catch (Exception ex)
{
throw new Exception($"创建表失败：{ex.Message}");
}
}- AddUser(string username, string password, string email) 函数
功能：向用户表插入新用户记录
参数处理：
对邮箱参数进行空值检查，如果为空则插入 DBNull.Value
异常处理：
捕获 SQL 异常 2627（唯一约束冲突），抛出"用户名已存在"异常
捕获其他异常并封装为添加用户失败消息
public bool AddUser(string username, string password, string email)
{
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
string insertSql = @"
INSERT INTO [user] (Username, Password, Email)
VALUES (@Username, @Password, @Email)";
using (SqlCommand command = new SqlCommand(insertSql, connection))
{
command.Parameters.AddWithValue("@Username", username);
command.Parameters.AddWithValue("@Password", password);
command.Parameters.AddWithValue("@Email", string.IsNullOrEmpty(email) ? DBNull.Value : (object)email);
int rowsAffected = command.ExecuteNonQuery();
return rowsAffected > 0;
}
}
}
catch (SqlException sqlEx)
{
if (sqlEx.Number == 2627) // 唯一约束冲突
{
throw new Exception("用户名已存在！");
}
throw new Exception($"添加用户失败：{sqlEx.Message}");
}
catch (Exception ex)
{
throw new Exception($"添加用户失败：{ex.Message}");
}
}- DeleteUser(int userId) 函数
功能：根据用户ID删除用户记录
实现方式：
构建 DELETE 语句，使用参数化查询防止SQL注入
通过 ExecuteNonQuery() 执行删除操作
返回布尔值表示删除是否成功（影响行数 > 0）
public bool DeleteUser(int userId)
{
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
string deleteSql = "DELETE FROM [user] WHERE Id = @Id";
using (SqlCommand command = new SqlCommand(deleteSql, connection))
{
command.Parameters.AddWithValue("@Id", userId);
int rowsAffected = command.ExecuteNonQuery();
return rowsAffected > 0;
}
}
}
catch (Exception ex)
{
throw new Exception($"删除用户失败：{ex.Message}");
}
}- UpdateUser(int userId, string username, string password, string email, bool isActive) 函数
功能：更新指定用户的完整信息
更新字段：用户名、密码、邮箱、激活状态
参数处理：
邮箱字段的空值处理与 AddUser 相同
所有字段均参与更新，无选择性更新逻辑
异常处理：包含唯一约束冲突的特殊处理
public bool UpdateUser(int userId, string username, string password, string email, bool isActive)
{
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
string updateSql = @"
UPDATE [user]
SET Username = @Username,
Password = @Password,
Email = @Email,
IsActive = @IsActive
WHERE Id = @Id";
using (SqlCommand command = new SqlCommand(updateSql, connection))
{
command.Parameters.AddWithValue("@Id", userId);
command.Parameters.AddWithValue("@Username", username);
command.Parameters.AddWithValue("@Password", password);
command.Parameters.AddWithValue("@Email", string.IsNullOrEmpty(email) ? DBNull.Value : (object)email);
command.Parameters.AddWithValue("@IsActive", isActive);
int rowsAffected = command.ExecuteNonQuery();
return rowsAffected > 0;
}
}
}
catch (SqlException sqlEx)
{
if (sqlEx.Number == 2627)
{
throw new Exception("用户名已存在！");
}
throw new Exception($"更新用户失败：{sqlEx.Message}");
}
catch (Exception ex)
{
throw new Exception($"更新用户失败：{ex.Message}");
}
}- GetAllUsers() 函数
功能：获取所有用户记录
返回类型：DataTable
查询逻辑：
按 Id 排序返回所有用户
使用 SqlDataAdapter 填充 DataTable
包含完整的用户字段选择
public DataTable GetAllUsers()
{
DataTable dataTable = new DataTable();
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
string selectSql = @"
SELECT
Id,
Username,
Password,
Email,
CreatedDate,
LastLogin,
IsActive
FROM [user]
ORDER BY Id";
using (SqlCommand command = new SqlCommand(selectSql, connection))
using (SqlDataAdapter adapter = new SqlDataAdapter(command))
{
adapter.Fill(dataTable);
}
}
}
catch (Exception ex)
{
throw new Exception($"查询用户失败：{ex.Message}");
}
return dataTable;
}- GetUserById(int userId) 函数
功能：根据用户ID精确查询用户
查询方式：使用参数化查询，精确匹配 Id 字段
public DataTable GetUserById(int userId)
{
DataTable dataTable = new DataTable();
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
string selectSql = "SELECT * FROM [user] WHERE Id = @Id";
using (SqlCommand command = new SqlCommand(selectSql, connection))
{
command.Parameters.AddWithValue("@Id", userId);
using (SqlDataAdapter adapter = new SqlDataAdapter(command))
{
adapter.Fill(dataTable);
}
}
}
}
catch (Exception ex)
{
throw new Exception($"查询用户失败：{ex.Message}");
}
return dataTable;
}- GetUserByUsername(string username) 函数
功能：根据用户名模糊查询用户
查询方式：使用 LIKE 操作符和 % 通配符进行模糊匹配
参数处理：在参数值前后添加 % 通配符
public DataTable GetUserByUsername(string username)
{
DataTable dataTable = new DataTable();
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
string selectSql = "SELECT * FROM [user] WHERE Username LIKE @Username";
using (SqlCommand command = new SqlCommand(selectSql, connection))
{
command.Parameters.AddWithValue("@Username", $"%{username}%");
using (SqlDataAdapter adapter = new SqlDataAdapter(command))
{
adapter.Fill(dataTable);
}
}
}
}
catch (Exception ex)
{
throw new Exception($"查询用户失败：{ex.Message}");
}
return dataTable;
}Form1 类详细功能分析
- 构造函数
初始化流程：
初始化界面组件
创建 UserService 实例
调用 InitializeDatabase()（当前被注释）
调用 LoadUserData() 加载初始数据
public Form1()
{
InitializeComponent();
InitializeDatabase();
LoadUserData();
}- InitializeDatabase() 函数
功能：初始化数据库表结构
当前状态：表创建功能被注释，仅保留异常处理框架
private void InitializeDatabase()
{
try
{
//userService.CreateUserTableIfNotExists();
}
catch (Exception ex)
{
MessageBox.Show($"数据库初始化失败：{ex.Message}", "错误",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}- btnAdd_Click() 事件处理函数
功能：处理添加用户按钮点击
验证逻辑：
检查用户名和密码是否为空或空白
显示警告消息如果验证失败
执行流程：
调用 userService.AddUser() 添加用户
成功后清空输入框并刷新数据
private void btnAdd_Click(object sender, EventArgs e)
{
try
{
if (string.IsNullOrWhiteSpace(txtUsername.Text) || string.IsNullOrWhiteSpace(txtPassword.Text))
{
MessageBox.Show("用户名和密码不能为空！", "警告",
MessageBoxButtons.OK, MessageBoxIcon.Warning);
return;
}
bool success = userService.AddUser(
txtUsername.Text.Trim(),
txtPassword.Text,
txtEmail.Text.Trim()
);
if (success)
{
MessageBox.Show("用户添加成功！", "成功",
MessageBoxButtons.OK, MessageBoxIcon.Information);
ClearInputs();
LoadUserData();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "错误",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}- btnUpdate_Click() 事件处理函数
功能：处理更新用户按钮点击
前置检查：
验证是否在 DataGridView 中选择了用户
获取当前选中行的用户ID
执行流程：
调用 userService.UpdateUser() 更新用户信息
成功后清空输入并刷新显示
private void btnUpdate_Click(object sender, EventArgs e)
{
if (dataGridView1.CurrentRow == null)
{
MessageBox.Show("请先选择要修改的用户！", "提示",
MessageBoxButtons.OK, MessageBoxIcon.Information);
return;
}
try
{
int userId = Convert.ToInt32(dataGridView1.CurrentRow.Cells["Id"].Value);
bool success = userService.UpdateUser(
userId,
txtUsername.Text.Trim(),
txtPassword.Text,
txtEmail.Text.Trim(),
chkIsActive.Checked
);
if (success)
{
MessageBox.Show("用户更新成功！", "成功",
MessageBoxButtons.OK, MessageBoxIcon.Information);
ClearInputs();
LoadUserData();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "错误",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}- btnDelete_Click() 事件处理函数
功能：处理删除用户按钮点击
确认机制：
显示确认对话框要求用户确认删除操作
仅在用户选择"是"时执行删除
执行流程：
获取选中行的用户ID
调用 userService.DeleteUser() 删除用户
成功后刷新数据网格
private void btnDelete_Click(object sender, EventArgs e)
{
if (dataGridView1.CurrentRow == null)
{
MessageBox.Show("请先选择要删除的用户！", "提示",
MessageBoxButtons.OK, MessageBoxIcon.Information);
return;
}
var result = MessageBox.Show("确定要删除这个用户吗？", "确认删除",
MessageBoxButtons.YesNo, MessageBoxIcon.Question);
if (result == DialogResult.Yes)
{
try
{
int userId = Convert.ToInt32(dataGridView1.CurrentRow.Cells["Id"].Value);
bool success = userService.DeleteUser(userId);
if (success)
{
MessageBox.Show("用户删除成功！", "成功",
MessageBoxButtons.OK, MessageBoxIcon.Information);
LoadUserData();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "错误",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
}- btnSearch_Click() 事件处理函数
功能：处理搜索用户按钮点击
搜索逻辑：
如果搜索框为空，显示所有用户 (GetAllUsers())
如果搜索框有内容，按用户名模糊搜索 (GetUserByUsername())
结果显示：直接将查询结果绑定到 DataGridView
private void btnSearch_Click(object sender, EventArgs e)
{
try
{
DataTable users;
if (string.IsNullOrWhiteSpace(txtSearch.Text))
{
users = userService.GetAllUsers();
}
else
{
users = userService.GetUserByUsername(txtSearch.Text.Trim());
}
dataGridView1.DataSource = users;
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "错误",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}- btnRefresh_Click() 事件处理函数
功能：处理刷新按钮点击，重新加载所有用户数据
private void btnRefresh_Click(object sender, EventArgs e)
{
LoadUserData();
}- LoadUserData() 函数
功能：加载并显示所有用户数据
界面配置：
将用户数据绑定到 DataGridView
设置列标题的中文显示文本
配置各列的显示名称
private void LoadUserData()
{
try
{
DataTable users = userService.GetAllUsers();
dataGridView1.DataSource = users;
// 设置列标题
if (dataGridView1.Columns.Count > 0)
{
dataGridView1.Columns["Id"].HeaderText = "ID";
dataGridView1.Columns["Username"].HeaderText = "用户名";
dataGridView1.Columns["Password"].HeaderText = "密码";
dataGridView1.Columns["Email"].HeaderText = "邮箱";
dataGridView1.Columns["CreatedDate"].HeaderText = "创建时间";
dataGridView1.Columns["LastLogin"].HeaderText = "最后登录";
dataGridView1.Columns["IsActive"].HeaderText = "是否激活";
}
}
catch (Exception ex)
{
MessageBox.Show($"加载数据失败：{ex.Message}", "错误",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}- dataGridView1_SelectionChanged() 事件处理函数
功能：处理数据网格选择变化事件
数据绑定：
当用户选择不同行时，自动将选中用户的数据填充到编辑表单
填充字段包括：用户名、密码、邮箱、激活状态
处理空值情况，使用空字符串替代 null 值
private void dataGridView1_SelectionChanged(object sender, EventArgs e)
{
if (dataGridView1.CurrentRow != null && !dataGridView1.CurrentRow.IsNewRow)
{
DataGridViewRow row = dataGridView1.CurrentRow;
txtUsername.Text = row.Cells["Username"].Value?.ToString() ?? "";
txtPassword.Text = row.Cells["Password"].Value?.ToString() ?? "";
txtEmail.Text = row.Cells["Email"].Value?.ToString() ?? "";
chkIsActive.Checked = Convert.ToBoolean(row.Cells["IsActive"].Value);
}
}- ClearInputs() 函数
功能：清空所有输入控件
清理范围：
清空用户名、密码、邮箱文本框
重置激活状态复选框为选中状态
private void ClearInputs()
{
txtUsername.Clear();
txtPassword.Clear();
txtEmail.Clear();
chkIsActive.Checked = true;
}二、所有源码
UserService.cs文件源码
using System;
using System;
using System.Data;
using System.Data.SqlClient;
using System.Windows.Forms;
namespace DatabaseHelper
{
public class UserService
{
//private string connectionString = @"Data Source=(LocalDB)\MSSQLLocalDB;AttachDbFilename=|DataDirectory|\mydb.mdf;Integrated Security=True;Connect Timeout=30";
private string connectionString = @"Data Source = (LocalDB)\MSSQLLocalDB;AttachDbFilename=C:\Users\a\Desktop\APP_C#\16_sqlserver\DatabaseHelper\DatabaseHelper\App_Data\mydb.mdf;
Integrated Security=True;Connect Timeout=30";
// 创建user表（如果不存在）
public void CreateUserTableIfNotExists()
{
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
string createTableSql = @"
IF NOT EXISTS (SELECT * FROM sysobjects WHERE name='user' AND xtype='U')
BEGIN
CREATE TABLE [user] (
Id INT IDENTITY(1,1) PRIMARY KEY,
Username NVARCHAR(50) NOT NULL UNIQUE,
Password NVARCHAR(100) NOT NULL,
Email NVARCHAR(100),
CreatedDate DATETIME NOT NULL DEFAULT GETDATE(),
LastLogin DATETIME NULL,
IsActive BIT NOT NULL DEFAULT 1
)
PRINT 'User表创建成功！'
END";
using (SqlCommand command = new SqlCommand(createTableSql, connection))
{
command.ExecuteNonQuery();
}
}
}
catch (Exception ex)
{
throw new Exception($"创建表失败：{ex.Message}");
}
}
// 增加用户
public bool AddUser(string username, string password, string email)
{
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
string insertSql = @"
INSERT INTO [user] (Username, Password, Email)
VALUES (@Username, @Password, @Email)";
using (SqlCommand command = new SqlCommand(insertSql, connection))
{
command.Parameters.AddWithValue("@Username", username);
command.Parameters.AddWithValue("@Password", password);
command.Parameters.AddWithValue("@Email", string.IsNullOrEmpty(email) ? DBNull.Value : (object)email);
int rowsAffected = command.ExecuteNonQuery();
return rowsAffected > 0;
}
}
}
catch (SqlException sqlEx)
{
if (sqlEx.Number == 2627) // 唯一约束冲突
{
throw new Exception("用户名已存在！");
}
throw new Exception($"添加用户失败：{sqlEx.Message}");
}
catch (Exception ex)
{
throw new Exception($"添加用户失败：{ex.Message}");
}
}
// 删除用户
public bool DeleteUser(int userId)
{
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
string deleteSql = "DELETE FROM [user] WHERE Id = @Id";
using (SqlCommand command = new SqlCommand(deleteSql, connection))
{
command.Parameters.AddWithValue("@Id", userId);
int rowsAffected = command.ExecuteNonQuery();
return rowsAffected > 0;
}
}
}
catch (Exception ex)
{
throw new Exception($"删除用户失败：{ex.Message}");
}
}
// 修改用户
public bool UpdateUser(int userId, string username, string password, string email, bool isActive)
{
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
string updateSql = @"
UPDATE [user]
SET Username = @Username,
Password = @Password,
Email = @Email,
IsActive = @IsActive
WHERE Id = @Id";
using (SqlCommand command = new SqlCommand(updateSql, connection))
{
command.Parameters.AddWithValue("@Id", userId);
command.Parameters.AddWithValue("@Username", username);
command.Parameters.AddWithValue("@Password", password);
command.Parameters.AddWithValue("@Email", string.IsNullOrEmpty(email) ? DBNull.Value : (object)email);
command.Parameters.AddWithValue("@IsActive", isActive);
int rowsAffected = command.ExecuteNonQuery();
return rowsAffected > 0;
}
}
}
catch (SqlException sqlEx)
{
if (sqlEx.Number == 2627)
{
throw new Exception("用户名已存在！");
}
throw new Exception($"更新用户失败：{sqlEx.Message}");
}
catch (Exception ex)
{
throw new Exception($"更新用户失败：{ex.Message}");
}
}
// 查询所有用户
public DataTable GetAllUsers()
{
DataTable dataTable = new DataTable();
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
string selectSql = @"
SELECT
Id,
Username,
Password,
Email,
CreatedDate,
LastLogin,
IsActive
FROM [user]
ORDER BY Id";
using (SqlCommand command = new SqlCommand(selectSql, connection))
using (SqlDataAdapter adapter = new SqlDataAdapter(command))
{
adapter.Fill(dataTable);
}
}
}
catch (Exception ex)
{
throw new Exception($"查询用户失败：{ex.Message}");
}
return dataTable;
}
// 根据ID查询用户
public DataTable GetUserById(int userId)
{
DataTable dataTable = new DataTable();
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
string selectSql = "SELECT * FROM [user] WHERE Id = @Id";
using (SqlCommand command = new SqlCommand(selectSql, connection))
{
command.Parameters.AddWithValue("@Id", userId);
using (SqlDataAdapter adapter = new SqlDataAdapter(command))
{
adapter.Fill(dataTable);
}
}
}
}
catch (Exception ex)
{
throw new Exception($"查询用户失败：{ex.Message}");
}
return dataTable;
}
// 根据用户名查询用户
public DataTable GetUserByUsername(string username)
{
DataTable dataTable = new DataTable();
try
{
using (SqlConnection connection = new SqlConnection(connectionString))
{
connection.Open();
string selectSql = "SELECT * FROM [user] WHERE Username LIKE @Username";
using (SqlCommand command = new SqlCommand(selectSql, connection))
{
command.Parameters.AddWithValue("@Username", $"%{username}%");
using (SqlDataAdapter adapter = new SqlDataAdapter(command))
{
adapter.Fill(dataTable);
}
}
}
}
catch (Exception ex)
{
throw new Exception($"查询用户失败：{ex.Message}");
}
return dataTable;
}
}
}Form1.cs文件源码
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.Tasks;
using System.Windows.Forms;
namespace DatabaseHelper
{
public partial class Form1 : Form
{
private UserService userService = new UserService();
public Form1()
{
InitializeComponent();
InitializeDatabase();
LoadUserData();
}
private void InitializeDatabase()
{
try
{
//userService.CreateUserTableIfNotExists();
}
catch (Exception ex)
{
MessageBox.Show($"数据库初始化失败：{ex.Message}", "错误",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
// 添加用户
private void btnAdd_Click(object sender, EventArgs e)
{
try
{
if (string.IsNullOrWhiteSpace(txtUsername.Text) || string.IsNullOrWhiteSpace(txtPassword.Text))
{
MessageBox.Show("用户名和密码不能为空！", "警告",
MessageBoxButtons.OK, MessageBoxIcon.Warning);
return;
}
bool success = userService.AddUser(
txtUsername.Text.Trim(),
txtPassword.Text,
txtEmail.Text.Trim()
);
if (success)
{
MessageBox.Show("用户添加成功！", "成功",
MessageBoxButtons.OK, MessageBoxIcon.Information);
ClearInputs();
LoadUserData();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "错误",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
// 更新用户
private void btnUpdate_Click(object sender, EventArgs e)
{
if (dataGridView1.CurrentRow == null)
{
MessageBox.Show("请先选择要修改的用户！", "提示",
MessageBoxButtons.OK, MessageBoxIcon.Information);
return;
}
try
{
int userId = Convert.ToInt32(dataGridView1.CurrentRow.Cells["Id"].Value);
bool success = userService.UpdateUser(
userId,
txtUsername.Text.Trim(),
txtPassword.Text,
txtEmail.Text.Trim(),
chkIsActive.Checked
);
if (success)
{
MessageBox.Show("用户更新成功！", "成功",
MessageBoxButtons.OK, MessageBoxIcon.Information);
ClearInputs();
LoadUserData();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "错误",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
// 删除用户
private void btnDelete_Click(object sender, EventArgs e)
{
if (dataGridView1.CurrentRow == null)
{
MessageBox.Show("请先选择要删除的用户！", "提示",
MessageBoxButtons.OK, MessageBoxIcon.Information);
return;
}
var result = MessageBox.Show("确定要删除这个用户吗？", "确认删除",
MessageBoxButtons.YesNo, MessageBoxIcon.Question);
if (result == DialogResult.Yes)
{
try
{
int userId = Convert.ToInt32(dataGridView1.CurrentRow.Cells["Id"].Value);
bool success = userService.DeleteUser(userId);
if (success)
{
MessageBox.Show("用户删除成功！", "成功",
MessageBoxButtons.OK, MessageBoxIcon.Information);
LoadUserData();
}
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "错误",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
}
// 搜索用户
private void btnSearch_Click(object sender, EventArgs e)
{
try
{
DataTable users;
if (string.IsNullOrWhiteSpace(txtSearch.Text))
{
users = userService.GetAllUsers();
}
else
{
users = userService.GetUserByUsername(txtSearch.Text.Trim());
}
dataGridView1.DataSource = users;
}
catch (Exception ex)
{
MessageBox.Show(ex.Message, "错误",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
// 刷新数据
private void btnRefresh_Click(object sender, EventArgs e)
{
LoadUserData();
}
// 加载用户数据
private void LoadUserData()
{
try
{
DataTable users = userService.GetAllUsers();
dataGridView1.DataSource = users;
// 设置列标题
if (dataGridView1.Columns.Count > 0)
{
dataGridView1.Columns["Id"].HeaderText = "ID";
dataGridView1.Columns["Username"].HeaderText = "用户名";
dataGridView1.Columns["Password"].HeaderText = "密码";
dataGridView1.Columns["Email"].HeaderText = "邮箱";
dataGridView1.Columns["CreatedDate"].HeaderText = "创建时间";
dataGridView1.Columns["LastLogin"].HeaderText = "最后登录";
dataGridView1.Columns["IsActive"].HeaderText = "是否激活";
}
}
catch (Exception ex)
{
MessageBox.Show($"加载数据失败：{ex.Message}", "错误",
MessageBoxButtons.OK, MessageBoxIcon.Error);
}
}
// DataGridView选择行变化事件
private void dataGridView1_SelectionChanged(object sender, EventArgs e)
{
if (dataGridView1.CurrentRow != null && !dataGridView1.CurrentRow.IsNewRow)
{
DataGridViewRow row = dataGridView1.CurrentRow;
txtUsername.Text = row.Cells["Username"].Value?.ToString() ?? "";
txtPassword.Text = row.Cells["Password"].Value?.ToString() ?? "";
txtEmail.Text = row.Cells["Email"].Value?.ToString() ?? "";
chkIsActive.Checked = Convert.ToBoolean(row.Cells["IsActive"].Value);
}
}
// 清空输入框
private void ClearInputs()
{
txtUsername.Clear();
txtPassword.Clear();
txtEmail.Clear();
chkIsActive.Checked = true;
}
}
}三、效果演示
可以进行用户的添加，删除，修改和查询
