优化这段代码 while (MonitoringThread) { try { if (MonitoringList.Count > 0) { foreach (var item in MonitoringList) { try { if (item.ReadCache) item.Value = PLCRpcClient.GetValueFromPLC(item.Id, item.Address, item.type).ToString(); else item.Value = PLCRpcClient.GetValueFromPLCNotCache(item.Id, item.Address, item.type).ToString(); } catch (Exception ex) { LogHelper.Error(ex); } } dataGridView1.Invoke(new Action(() => { dataGridView1.Refresh(); })); } } catch (Exception ex) { LogHelper.Error(ex); } Thread.Sleep(2 * 1000); }

这段代码可以进行如下的优化：

1. 使用异步/多线程方式进行数据获取和刷新，避免阻塞主线程，提高用户体验。

2. 使用定时器或者任务调度框架（如 Quartz.NET 等）替代 while 循环，避免线程占用过多 CPU 资源。

3. 使用并发集合（如 ConcurrentDictionary 等）替代 List，避免多线程下的读写冲突。

4. 使用委托/事件机制代替硬编码的 UI 操作，提高代码的可维护性和可扩展性。

5. 避免频繁的网络通信，可以在获取数据后进行本地缓存，避免重复访问。

6. 使用日志框架记录异常信息，方便问题的排查和修复。

相关问题

来一段.net 6 Websocket 聊天功能代码，要详细的，实用的

当然，这里是一段使用.NET 6实现Websocket聊天功能的代码。这段代码实现了基本的聊天功能，包括用户连接、断开连接、发送消息等。

首先，我们需要在Startup.cs文件中添加WebSocket中间件：

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    // ...

    app.UseWebSockets();

    app.Use(async (context, next) =>
    {
        if (context.Request.Path == "/ws")
        {
            if (context.WebSockets.IsWebSocketRequest)
            {
                WebSocket webSocket = await context.WebSockets.AcceptWebSocketAsync();
                await ChatManager.AddWebSocketAsync(webSocket);
            }
            else
            {
                context.Response.StatusCode = 400;
            }
        }
        else
        {
            await next();
        }
    });

    // ...
}

然后，我们可以创建一个ChatManager类来管理聊天室的WebSocket连接和消息发送：

public class ChatManager
{
    private static readonly List<WebSocket> _webSockets = new List<WebSocket>();

    public static async Task AddWebSocketAsync(WebSocket webSocket)
    {
        _webSockets.Add(webSocket);

        try
        {
            await ReceiveAsync(webSocket);
        }
        catch
        {
            await RemoveWebSocketAsync(webSocket);
        }
    }

    public static async Task RemoveWebSocketAsync(WebSocket webSocket)
    {
        _webSockets.Remove(webSocket);
        await webSocket.CloseAsync(WebSocketCloseStatus.NormalClosure, "WebSocket closed", CancellationToken.None);
    }

    public static async Task SendAllAsync(string message)
    {
        var buffer = Encoding.UTF8.GetBytes(message);
        var tasks = new List<Task>();
        foreach (var webSocket in _webSockets)
        {
            if (webSocket.State == WebSocketState.Open)
            {
                tasks.Add(webSocket.SendAsync(new ArraySegment<byte>(buffer), WebSocketMessageType.Text, true, CancellationToken.None));
            }
        }

        await Task.WhenAll(tasks);
    }

    private static async Task ReceiveAsync(WebSocket webSocket)
    {
        var buffer = new byte[1024 * 4];
        while (webSocket.State == WebSocketState.Open)
        {
            var result = await webSocket.ReceiveAsync(new ArraySegment<byte>(buffer), CancellationToken.None);

            if (result.MessageType == WebSocketMessageType.Close)
            {
                await RemoveWebSocketAsync(webSocket);
            }
            else if (result.MessageType == WebSocketMessageType.Text)
            {
                var message = Encoding.UTF8.GetString(buffer, 0, result.Count);
                await SendAllAsync(message);
            }
        }
    }
}

最后，我们可以在客户端使用JavaScript来连接WebSocket和发送消息：

const webSocket = new WebSocket('ws://localhost:5000/ws');
webSocket.addEventListener('open', () => {
    console.log('WebSocket connected');
});
webSocket.addEventListener('message', event => {
    console.log(event.data);
});
document.querySelector('#send-btn').addEventListener('click', () => {
    const message = document.querySelector('#message-input').value;
    webSocket.send(message);
});

这样，我们就实现了一个基本的Websocket聊天功能。

java分页完整代码_JavaWeb中的简单分页完整代码(推荐)

以下是JavaWeb中的简单分页完整代码，使用JSP和Servlet实现：

1. 在JSP页面中，使用表格展示数据并添加分页导航：

<%@ page language="java" contentType="text/html; charset=UTF-8"
    pageEncoding="UTF-8"%>
<%@ taglib uri="http://java.sun.com/jsp/jstl/core" prefix="c" %>
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>分页示例</title>
</head>
<body>
    <h1>分页示例</h1>
    <table border="1">
        <tr>
            <th>ID</th>
            <th>姓名</th>
            <th>年龄</th>
        </tr>
        <c:forEach items="${list}" var="user">
            <tr>
                <td>${user.id}</td>
                <td>${user.name}</td>
                <td>${user.age}</td>
            </tr>
        </c:forEach>
    </table>
    <br>
    <c:if test="${page > 1}">
        <a href="list?page=${page - 1}">上一页</a>
    </c:if>
    <c:if test="${page < pageCount}">
        <a href="list?page=${page + 1}">下一页</a>
    </c:if>
</body>
</html>

2. 在Servlet中查询数据库并设置分页相关参数：

package com.example.servlet;

import java.io.IOException;
import java.util.List;

import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import com.example.dao.UserDao;
import com.example.entity.User;

@WebServlet("/list")
public class UserListServlet extends HttpServlet {
    private static final long serialVersionUID = 1L;

    protected void doGet(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        int pageSize = 10; // 每页显示的记录数
        int page = Integer.parseInt(request.getParameter("page")); // 当前页码
        int offset = (page - 1) * pageSize; // 当前页第一条记录的偏移量
        UserDao dao = new UserDao();
        List<User> list = dao.list(offset, pageSize); // 查询当前页的数据
        int totalCount = dao.count(); // 总记录数
        int pageCount = (int) Math.ceil(totalCount * 1.0 / pageSize); // 总页数
        request.setAttribute("list", list);
        request.setAttribute("page", page);
        request.setAttribute("pageCount", pageCount);
        request.getRequestDispatcher("list.jsp").forward(request, response);
    }

    protected void doPost(HttpServletRequest request, HttpServletResponse response)
            throws ServletException, IOException {
        doGet(request, response);
    }
}

3. 在DAO中查询数据库并返回数据：

package com.example.dao;

import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.util.ArrayList;
import java.util.List;

import com.example.entity.User;

public class UserDao {
    private String url = "jdbc:mysql://localhost:3306/test?useSSL=false&serverTimezone=UTC";
    private String username = "root";
    private String password = "123456";

    public List<User> list(int offset, int pageSize) {
        List<User> list = new ArrayList<>();
        try (Connection conn = DriverManager.getConnection(url, username, password)) {
            String sql = "SELECT * FROM user LIMIT ?, ?";
            try (PreparedStatement stmt = conn.prepareStatement(sql)) {
                stmt.setInt(1, offset);
                stmt.setInt(2, pageSize);
                try (ResultSet rs = stmt.executeQuery()) {
                    while (rs.next()) {
                        User user = new User();
                        user.setId(rs.getInt("id"));
                        user.setName(rs.getString("name"));
                        user.setAge(rs.getInt("age"));
                        list.add(user);
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return list;
    }

    public int count() {
        int count = 0;
        try (Connection conn = DriverManager.getConnection(url, username, password)) {
            String sql = "SELECT COUNT(*) FROM user";
            try (PreparedStatement stmt = conn.prepareStatement(sql)) {
                try (ResultSet rs = stmt.executeQuery()) {
                    if (rs.next()) {
                        count = rs.getInt(1);
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return count;
    }
}

可以根据需求自行修改代码，例如更改每页显示的记录数、更改查询语句等。