会员可以在此提问,百战程序员老师有问必答
对大家有帮助的问答会被标记为“推荐”
看完课程过来浏览一下别人提的问题,会帮你学得更全面
截止目前,同学们一共提了 133793个问题
JAVA 全系列/第九阶段:SpringBoot与MybatisPlus/Spring Boot旧 4787楼
人工智能/第三阶段:人工智能基础-Python科学计算和可视化/数据可视化模块 4789楼
Java架构课程/第九阶段:消息中间件/ActiveMQ 4790楼
JAVA 全系列/第六阶段:JavaWeb开发/Servlet技术详解 4792楼
JAVA 全系列/第六阶段:JavaWeb开发/Web实战案例 4793楼
JAVA 全系列/第一阶段:AI驱动的JAVA编程/JAVA入门和背景知识 4795楼

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>小米</title>
    <link rel="stylesheet" href="./css/reset.css">
    <link rel="stylesheet" href="./css/mi.css">
    <link rel="stylesheet" href="./css/iconfont/iconfont.css">
</head>
<body>

    <!-- 头部开始 -->
    <div class="header">
        <a href="#">
            <img src="./images/top.jpg" alt="">
        </a>
    </div>
    <!-- 头部结束 -->
    <!-- 黑色导航部分开始 -->
    <!-- 
        黑色导航实现步骤:
            1. 主容器,背景黑色
            2. 内容部分居中显示,容器处理
            3. 左导航和右导航
            4. 动画
     -->
    <div class="black-nav">
        <div class="wrap">
            <ul class="black-nav-left">
                <li><a href="#">小米商城</a><span>|</span></li>
                <li><a href="#">MIUI</a><span>|</span></li>
                <li><a href="#">loT</a><span>|</span></li>
                <li><a href="#">云服务</a><span>|</span></li>
                <li><a href="#">天星数科</a><span>|</span></li>
                <li><a href="#">有品</a><span>|</span></li>
                <li><a href="#">小爱开放平台</a><span>|</span></li>
                <li><a href="#">企业团购</a><span>|</span></li>
                <li><a href="#">资质证照</a><span>|</span></li>
                <li><a href="#">协议规则</a><span>|</span></li>
                <li>
                    <a href="#">下载APP</a>
                    <span>|</span>
                    <div class="download">
                        <img src="./images/download.png" alt="">
                        <p>小米商城APP</p>
                    </div>
                    <div class="stri"></div>
                </li>
                <li><a href="#">智能生活</a><span>|</span></li>
                <li><a href="#">SelectLocation</a><span>|</span></li>
            </ul>
            <ul class="black-nav-right">
                <li><a href="#">登录</a><span>|</span></li>
                <li><a href="#">注册</a><span>|</span></li>
                <li><a href="#">消息通知</a><span>|</span></li>
                <li class="cart">
                    <a href="#">
                        <i class="iconfont">&#xe607;</i>
                        <i>购物车(0)</i>
                    </a>
                    <div class="cart-list">
                        购物车中还没有商品,赶紧选购吧
                    </div>
                </li>
            </ul>
        </div>
    </div>
    <!-- 黑色导航部分结束 -->
    <!-- 白色导航开始 -->
    <div class="white-nav">
        <div class="wrap">
            <div class="logo">
                <img src="./images/mi-home.png" alt="" class="mi-home">
                <img src="./images/mi-logo.png" alt="" class="mi-logo">
            </div>
            <div class="nav-bar">
                <ul>
                    <li><a href="#"><img src="./images/zzxsh.gif" alt=""></a></li>
                    <li>
                        <a href="#">小米手机</a>
                        <div class="nav-bar-list">
                            <div class="wrap">
                                <ul>
                                    <li>
                                        <a href="#">
                                            <div class="img-box">
                                                <img src="./images/phone.png" alt="">
                                            </div>
                                            <p class="name">小米10至尊纪念版</p>
                                            <p class="price">5200元</p>
                                        </a>
                                    </li>
                                    <li>
                                        <a href="#">
                                            <div class="img-box">
                                                <img src="./images/phone.png" alt="">
                                            </div>
                                            <p class="name">小米10至尊纪念版</p>
                                            <p class="price">5200元</p>
                                        </a>
                                    </li>
                                    <li>
                                        <a href="#">
                                            <div class="img-box">
                                                <img src="./images/phone.png" alt="">
                                            </div>
                                            <p class="name">小米10至尊纪念版</p>
                                            <p class="price">5200元</p>
                                        </a>
                                    </li>
                                    <li>
                                        <a href="#">
                                            <div class="img-box">
                                                <img src="./images/phone.png" alt="">
                                            </div>
                                            <p class="name">小米10至尊纪念版</p>
                                            <p class="price">5200元</p>
                                        </a>
                                    </li>
                                </ul>
                            </div>
                        </div>
                    </li>
                    <li><a href="#">电视</a></li>
                    <li><a href="#">笔记本</a></li>
                    <li><a href="#">家电</a></li>
                    <li><a href="#">路由器</a></li>
                    <li><a href="#">智能硬件</a></li>
                    <li><a href="#">服务</a></li>
                    <li><a href="#">社区</a></li>
                </ul>
            </div>
            <div class="search">
                <input type="text" placeholder="元宇宙">
                <button class="iconfont">&#xe63d;</button>
            </div> 
        </div>
    </div>
    <!-- 白色导航结束 -->
   
</body>
</html>
老师为什么白色导航下居中不了啊,还有黑色导航

WEB前端全系列/第一阶段:HTML5+CSS3模块/商城官网项目 4796楼

为什么我的fo-each遍历不出来



package com.itbaizhan;

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

/**
* 动态条件测试类
*/

public class DynamicConditionQueryTest {
   public List<Users> queryUsers(Users users){
       List<Users> list= new ArrayList<>();
       Connection conn =null;
       PreparedStatement ps = null;
       ResultSet rs = null;
       try{
           conn = JdbcUtils.getConnection();
           //拼接查询sql语句
           String sql = this.generate(users);
          // System.out.println(sql);
           ps = conn.prepareStatement(sql);
           //执行语句
           rs = ps.executeQuery();
           while (rs.next()){
               Users users1 = new Users();
               users1.setUserid(rs.getInt("userid"));
               users1.setUsername(rs.getString("username"));
               users1.setUserage(rs.getInt("userage"));
               list.add(users1);
           }
       }catch (Exception e){
           e.printStackTrace();
       }finally {
           JdbcUtils.closeResource(rs,ps,conn);
       }

       return list;
   }
   public String generate(Users users){
       StringBuilder sb = new StringBuilder("select * from users where 1=1 ");
       if (users.getUserid()>0){
           sb.append(" and userid = ").append(users.getUserid());
       }
       if (users.getUsername() != null && users.getUsername().length()>0){
           sb.append(" and username ='").append(users.getUsername()).append("'");
       }
       if (users.getUserage()>0){
           sb.append(" and userage = ").append(users.getUserage());
       }
       return sb.toString();
   }

   public static void main(String[] args) {
       DynamicConditionQueryTest d = new DynamicConditionQueryTest();
       Users users = new Users();
       users.setUserid(22);
       users.setUsername("yuan");
       List<Users> list = d.queryUsers(users);
       for (Users t:list){
           System.out.println(t.getUserid()+" "+t.getUsername()+" "+t.getUserage());
           System.out.println(" ni");
       }
   }
}


"C:\Program Files\Java\jdk-11.0.12\bin\java.exe" "-javaagent:D:\IntelliJ IDEA Community Edition 2023.1\lib\idea_rt.jar=65185:D:\IntelliJ IDEA Community Edition 2023.1\bin" -Dfile.encoding=UTF-8 -classpath D:\Mycode\jdbcdemo\out\production\jdbcdemoMysql;D:\Mycode\jdbcdemo\lib\mysql-connector-java-5.1.48.jar com.itbaizhan.DynamicConditionQueryTest


Process finished with exit code 0



JAVA 全系列/第四阶段:数据库与AI协同技术实战/JDBC技术 4798楼
Python 全系列/第十六阶段:Python 爬虫开发/scrapy框架使用 4800楼

课程分类

百战程序员微信公众号

百战程序员微信小程序

©2014-2025百战汇智(北京)科技有限公司 All Rights Reserved 北京亦庄经济开发区科创十四街 赛蒂国际工业园
网站维护:百战汇智(北京)科技有限公司
京公网安备 11011402011233号    京ICP备18060230号-3    营业执照    经营许可证:京B2-20212637