对List的数据进行分组
 
一：我们平常在工作的时候可能会遇到要对List里面的数据进行分组,在jdk1.8中有方法帮我们解决,而在1.8之前我们要实现这样的功能就需要自己手动实现分组
 
我们先定义一个User类
 
public class User {
    private int id;
    private String contractName;

    public User(int id, String contractName) {
        this.id = id;
        this.contractName = contractName;
    }

    public int getId() {
        return id;
    }

    public void setId(int id) {
        this.id = id;
    }

    public String getContractName() {
        return contractName;
    }

    public void setContractName(String contractName) {
        this.contractName = contractName;
    }

    @Override
    public String toString() {
        return "User{" +
                "id=" + id +
                ", contractName='" + contractName + '\'' +
                '}';
    }
}
 
我们先实现自定义List数据分组
 
public static List<User> listDataSort(List<User> list){
        List<User> transformList=new ArrayList<User>();
        //创建一个map,来让list分组把一个List<User>分成多个List<User>
        Map<Integer,List<User>> map=new HashMap<Integer,List<User>>();
        //遍历传进来的list
        for (User user : list) {
            //如果map的某个key值已经存在同样的userId,则把这个user添加到这个key所在的List<User>
            if(map.containsKey(user.getId())){
                map.get(user.getId()).add(user);
            }
            else{
                //如果没有相同的id,就新创建一个List
                List<User> newList=new ArrayList<User>();
                //添加数据
                newList.add(user);
                map.put(user.getId(),newList);
            }
        }
        /*
        把Map转换成List<List<User>>,为什么会变成List<List<User>>,原因在于
        map是以多个userId为键值,存储多个List<User>,map.values转换成list就会变成
        List<List<User>>
         */
        List<List<User>> lists=new ArrayList<List<User>>(map.values());
        //遍历lists
        for (List<User> users : lists) {
            for (User user : users) {
                //现在添加进来的User都是分好组的
                transformList.add(user);
            }
        }
        return transformList;
    }
 
进行测试
 
public static void main(String[] args) {
        List<User> list=new ArrayList<User>();
        list.add(new User(1,"一号合同"));
        list.add(new User(2,"一号合同"));
        list.add(new User(1,"二号合同"));
        list.add(new User(3,"一号合同"));
        list.add(new User(3,"二号合同"));
        list.add(new User(2,"二号合同"));
        System.out.println("分组前:"+list);
        System.out.println("分组后:"+listDataSort(list));
    }
 
 
利用jdk1.8的新方法进行分组
 
public static List<User> groupList(List<User> users) {
        List<User> transformList=new ArrayList<User>();
        //创建一个List<List<User>>来接收工具排序后遍历出来的多个List<User>
        List<List<User>> lists=new ArrayList<List<User>>();
        //jdk1.8新增加的List.stream(),利用流来操作
        /*
        * stream()是把List转换成流
        * collect()是把流转换回集合
        * Collectors.groupingBy()对collect进行分组
        * User::getId,根据User对象的getId进行分组
        * Collectors.toList() 把每一组转换成List集合
        * forEach() 进行遍历,内部自定义方法 () -> {} 这是lambada表达式,遍历出每个List<User>
        * 把每个List<User>放进lists
        * forEach里面的id 可以写成任何字符串,比如s aa,bb等,
        * 因为我们是根据id分组的,所以写成id,usersById也可以写成任何值,
        * 比如s aa,bb等,lambada是自动填充数据的
        * */
        users.stream().collect(Collectors.groupingBy(User::getId,Collectors.toList()))
                .forEach((id,usersById) -> {
                    lists.add(usersById);
                });
        if(lists!=null){
            for (List<User> list : lists) {
                for (User user : list) {
                    transformList.add(user);
                }
            }
        }
        return transformList;
    }
 
进行测试
 
public static void main(String[] args) {
        List<User> list=new ArrayList<User>();
        list.add(new User(1,"一号合同"));
        list.add(new User(2,"一号合同"));
        list.add(new User(1,"二号合同"));
        list.add(new User(3,"一号合同"));
        list.add(new User(3,"二号合同"));
        list.add(new User(2,"二号合同"));
        System.out.println("分组前:"+list);
        System.out.println("分组后:"+groupList(list));
    }
 

 ``

如何根据某一字段对数据进行分组统计？
 在项目要求中要求实现此页面功能
 在这里要求统计公司20GP，40GP，40HC的柜量和TEU情况，
 
 下面是我实现此功能的页面
 
 啊啊，页面设计不好看，虽然实现的内容与要求的有些许差异，但是分组查询统计的功能是实现了
 下面是我经过思考编写的代码（在这里引用了BsgridPage）
 
// An highlighted block
public ActionResult Statistics(BsgridPage bsgridPage, int EntrustID, string WorkNumber, string StarDate, string EndDate,
             int PretendHarborID, int PurposeID, string ShipID, string ShipNext)//柜型柜量统计
        {
            #region
            try
            {
                var lisqtem = (from tbSetBox in myModels.SYS_Setbox
                                   //group by分组
                                   //group tbSetBox by tbSetBox.ShipcompanyID into tbShipcommanpay 
                                   //表示对tbSetBox按ShipcompanyID字段归类，其结果命名为tbShipcommanpay 
                                   //一旦重新命名，tbSetBox的作用域就结束了，所以，最后select时，
                               group tbSetBox by tbSetBox.ShipcompanyID into tbShipcommanpay
                               select new
                               {
                                   ShipcompanyID = tbShipcommanpay.Key,//接口提供一个属性 Key ，返回进行分组的关键字段的值
                                   TEU = tbShipcommanpay.Select(m => m.TEU),
                                   Score20GP = tbShipcommanpay.Where(m => m.Boxmodel == "20GP"),
                                   Score40GP = tbShipcommanpay.Where(m => m.Boxmodel == "40GP"),
                                   Score40HC = tbShipcommanpay.Where(m => m.Boxmodel == "40HC"),
                               }).ToList();

                var linqteml = (from tbSetBox in lisqtem
                                join tbShipcompany in myModels.SYS_Shipcompany on tbSetBox.ShipcompanyID equals tbShipcompany.ShipcompanyID
                                join tbShip in myModels.SYS_Ship on tbShipcompany.ShipID equals tbShip.ShipID
                                join tbWorkNumber in myModels.SYS_WorkNumber on tbShip.WorkNumberID equals tbWorkNumber.WorkNumberID
                                join tbEntrust in myModels.SYS_Entrust on tbShip.EntrustID equals tbEntrust.EntrustID
                                orderby tbSetBox.ShipcompanyID descending
                                select new SetBoxVo
                                {
                                    ShipcompanyID = tbShipcompany.ShipcompanyID,
                                    ShipName = tbShip.ShipName,
                                    ShipcompanyMC = tbShipcompany.ShipcompanyMC,
                                    Score20GP = tbSetBox.Score20GP.Count(),
                                    Score40GP = tbSetBox.Score40GP.Count(),
                                    Score40HC = tbSetBox.Score40HC.Count(),
                                    TEU = tbSetBox.TEU.Count(),
                                    Date = tbShip.DateShip.ToString(),
                                    DateShip = tbShip.DateShip,
                                    WorkNumber = tbWorkNumber.WorkNumber,
                                    EntrustMC = tbEntrust.EntrustMC,
                                    ShipNext = tbShip.ShipNext,
                                    EntrustID = tbEntrust.EntrustID,
                                    ShipID = tbShip.ShipID,
                                }).ToList();
                if (EntrustID > 0)
                {
                    linqteml = linqteml.Where(m => m.EntrustID == EntrustID).ToList();
                }
                if (PretendHarborID > 0)
                {
                    linqteml = linqteml.Where(m => m.PretendHarborID == PretendHarborID).ToList();
                }
                if (!string.IsNullOrEmpty(ShipID))
                {
                    linqteml = linqteml.Where(m => m.ShipName.Contains(ShipID)).ToList();
                }
                if (PurposeID > 0)
                {
                    linqteml = linqteml.Where(m => m.PurposeID == PurposeID).ToList();
                }
                if (!string.IsNullOrEmpty(WorkNumber))
                {
                    linqteml = linqteml.Where(m => m.WorkNumber.Contains(WorkNumber)).ToList();
                }
                if (!string.IsNullOrEmpty(ShipNext))
                {
                    linqteml = linqteml.Where(m => m.ShipNext.Contains(ShipNext)).ToList();
                }
                if (!string.IsNullOrEmpty(StarDate) && !string.IsNullOrEmpty(EndDate))
                {
                    DateTime starDate = Convert.ToDateTime(StarDate);
                    DateTime endDate = Convert.ToDateTime(EndDate);
                    linqteml = linqteml.Where(m => m.DateShip >= starDate && m.DateShip <= endDate).ToList();
                }
                int totals = linqteml.Count();
                List<SetBoxVo> listSet = linqteml
                    .Skip(bsgridPage.GetStartIndex())
                    .Take(bsgridPage.pageSize).ToList();
                Bsgrid<SetBoxVo> bsgrid = new Bsgrid<SetBoxVo>
                {
                    success = true,
                    totalRows = totals,
                    curPage = bsgridPage.curPage,
                    data = listSet
                };
                return Json(bsgrid, JsonRequestBehavior.AllowGet);
                #endregion
            }
            catch (Exception e)
            {
                Console.WriteLine(e);
            }
            return Json("", JsonRequestBehavior.AllowGet);
        }

先给excel添加开发工具及宏的设置。
 
先点击excel的office按钮，在菜单的右下角选“Excel选项”；
 
在Excel选项的常用页里“在功能区显示开发工具选项卡”打勾；
 
再点击信任中心里的“信任中心设置”；
 
选宏设置项，里面选择“启用所有宏”；
 
设置完后就会在excel工具栏显示如图：
 

 
 
然后点击Ｖisual Ｂasic　进行写代码：
 

 
 
最后点击运行就可以了。
 

 

被分组数据类型：包含n多个对象的数据
 
代码示例：
 
let data = [
    { key: 'xxx', name: 'yiyi', age: 12, money: 10 },
    { key: 'sss', name: 'iii', age: 13, money: 100 },
    { key: 'ddd', name: 'ooo', age: 13, money: 50 },
    { key: 'sss', name: 'mmm', age: 50, money: 90 },
    { key: 'ddd', name: '888', age: 13, money: 88 },
    { key: 'aaa', name: 'qqq', age: 30, money: 78 },
    { key: 'aaa', name: 'qqq', age: 13, money: 32 },
    { key: 'xxx', name: 'heh', age: 13, money: 95 },
    { key: 'sss', name: 'rtt', age: 15, money: 456 },
    { key: 'xxx', name: 'opp', age: 15, money: 91 },
    { key: 'ddd', name: 'gun', age: 19, money: 66 },
];

//data是要被分组的数据[]，key是分组依据的关键字
let getGroup=(data,key)=>{
    let groups={};
    data.forEach(c=>{
        let value=c[key];
        groups[value]=groups[value]||[];
        groups[value].push(c);
    });
    return groups;
}

console.log(getGroup(data,'key'))
 
调用这个getGroup方法得到的结果就是
 
{
    aaa:[
        {key: "aaa", name: "qqq", age: 30, money: 78},
        {key: "aaa", name: "qqq", age: 13, money: 32}
    ],
    ddd:[
        {key: "ddd", name: "ooo", age: 13, money: 50},
        {key: "ddd", name: "888", age: 13, money: 88},
        {key: "ddd", name: "gun", age: 19, money: 66}
    ],
    sss:[
        {key: "sss", name: "iii", age: 13, money: 100},
        {key: "sss", name: "mmm", age: 50, money: 90},
        {key: "sss", name: "rtt", age: 15, money: 456}
    ],
    xxx:[
        {key: "xxx", name: "yiyi", age: 12, money: 10}
        {key: "xxx", name: "heh", age: 13, money: 95}
        {key: "xxx", name: "opp", age: 15, money: 91}
    ]
}
 
这样同一组数据就在一个对象属性里面了，可以愉快的开始使用分组后的数据了