通用的下拉聯動封裝(級聯)_ZenDei技術網路在線

前言平時工作中下拉聯動是相對比較麻煩的地方，雖然邏輯簡單，但是需要寫一堆js跟ajax請求。現在打算在.net core mvc下封裝一個下拉聯動組件方便使用。下麵將實現一個國家語言省市區的多級聯動創建實體模型寫出對應下拉的Action方法這裡下拉contorler名稱約定為Dr ...

前言

平時工作中下拉聯動是相對比較麻煩的地方，雖然邏輯簡單，但是需要寫一堆js跟ajax請求。現在打算在.net core mvc下封裝一個下拉聯動組件方便使用。

下麵將實現一個國家語言省市區的多級聯動

創建實體模型

 1     public class UserModel
 2     {
 3         /// <summary>
 4         /// 用戶名
 5         /// </summary>
 6         public string UserName { get; set; }
 7 
 8 
 9         /// <summary>
10         /// 國家
11         /// </summary>
12         public int CountryId { get; set; }
13 
14         /// <summary>
15         /// 語言
16         /// </summary>
17         public int LanguageId { get; set; }
18 
19         /// <summary>
20         ///省
21         /// </summary>
22         public int PronviceId { get; set; }
23 
24         /// <summary>
25         /// 市
26         /// </summary>
27         public int CityId { get; set; }
28 
29         /// <summary>
30         /// 區
31         /// </summary>
32         public int GetDistrictId { get; set; }
33 
34     }
35 
36     public class Area
37     {
38         public int Id { get; set; }
39 
40         public string Name { get; set; }
41 
42         public int? ParentId { get; set; }
43     }
44 
45     public class Language
46     {
47         public int Id { get; set; }
48 
49         public int CountryId { get; set; }
50 
51         public string Name { get; set; }
52     }

寫出對應下拉的Action方法

這裡下拉contorler名稱約定為DropdownListController,Action名稱約定為 Get +欄位名的方式,參數名稱約定使用父級欄位的名稱。這樣在前臺頁面就不用指定獲取數據源的url了

 1   public class DropdownListController : Controller
 2     {
 3         private List<Area> areas;
 4 
 5         private List<Language> languages;
 6 
 7         public DropdownListController()
 8         {
 9             areas = new List<Area>
10             {
11                 new Area { Id = 1, Name = "中國", ParentId = null },
12                 new Area { Id = 2, Name = "美國", ParentId = null },
13                 new Area { Id = 3, Name = "江蘇省", ParentId = 1 },
14                 new Area { Id = 4, Name = "浙江省", ParentId = 1 },
15                 new Area { Id = 5, Name = "紐約州", ParentId = 2 },
16                 new Area { Id = 6, Name = "南京市", ParentId = 3 },
17                 new Area { Id = 7, Name = "杭州市", ParentId = 4 },
18                 new Area { Id = 8, Name = "紐約市", ParentId = 5 },
19                 new Area { Id = 9, Name = "曼哈頓區", ParentId = 8 },
20                 new Area { Id = 10, Name = "老廟區", ParentId = 6 },
21                 new Area { Id = 11, Name = "西湖區", ParentId = 7 }
22             };
23 
24             languages = new List<Language>
25             {
26                 new Language{ Id=1,CountryId=1, Name="簡體中文" },
27                 new Language{ Id=2,CountryId=2, Name="美式英語"},
28             };
29         }
30 
31         public IActionResult GetCountryId()
32         {
33             return Json(areas.FindAll(x => x.ParentId == null).Select(x => new { value = x.Id, text = x.Name }));
34         }
35 
36         public IActionResult GetLanguageId(int countryId)
37         {
38             return Json(languages.FindAll(x => x.CountryId == countryId).Select(x => new { value = x.Id, text = x.Name }));
39         }
40 
41         public IActionResult GetPronviceId(int countryId)
42         {
43             return Json(areas.FindAll(x => x.ParentId == countryId).Select(x => new { value = x.Id, text = x.Name }));
44         }
45 
46         public IActionResult GetCityId(int pronviceId)
47         {
48             return Json(areas.FindAll(x => x.ParentId == pronviceId).Select(x => new { value = x.Id, text = x.Name }));
49         }
50 
51         public IActionResult GetDistrictId(int cityId)
52         {
53             return Json(areas.FindAll(x => x.ParentId == cityId).Select(x => new { value = x.Id, text = x.Name }));
54         }
55     }

前臺Html

引用了 bootstrap, jquery

@model UserModel

 <a asp-action="Edit" class="btn btn-success m-b-15">去編輯頁</a>
<div class="form-inline row">
    <div class="form-group ">
        <label>國家</label>
        <select asp-for="CountryId" class="form-control" asp-items="ViewBag.CountryList"
                data-select-childids="LanguageId,PronviceId">
            <option value="">請選擇</option>
        </select>
    </div>
    <div class="form-group ">
        <label>語言</label>
        <select asp-for="LanguageId" class="form-control">
            <option value="">請選擇</option>
        </select>
    </div>
    <div class="form-group">
        <label>省</label>
        <select asp-for="PronviceId" class="form-control" data-select-childids="CityId">
         <option value="">請選擇</option>
        </select>
    </div>
    <div class="form-group">
        <label>市</label>
        <select asp-for="CityId" class="form-control"   data-select-childids="DistrictId">
            <option value="">請選擇</option>
        </select>
    </div>
    <div class="form-group">
        <label>區</label>
        <select asp-for="DistrictId" class="form-control">
            <option value="">請選擇</option>
        </select>
    </div>
</div>

下拉聯動的js,基於 jquery

$(function () {
    //下拉聯動初始化
    $('select[data-select-childids]').each(function () {
        getChildSelect($(this).attr("id"), true);
    });

    //下拉聯動  data-select-childids 填寫聯動的Id,data-select-url 數據請求路徑,data-select-paramids 追加的參數,data-select-value 當前值
    $('select[data-select-childids]').change(function (e) {
        getChildSelect($(this).attr("id"));
    });

    //清空下拉聯動子選擇項
    function getChildSelect(selectid, isInit) {
        var select = $('#' + selectid);

        var selectchildIds = select.data('select-childids');
        if (!selectchildIds) return;
        var childIds = selectchildIds.split(',')

        for (var i = 0; i < childIds.length; i++) {
            if (!childIds[i]) continue;

            var child = $('#' + childIds[i]);
            var childValue = child.val();
            if (!childValue)
                childValue = child.data("select-value");

            child.empty();

            //預設值設定
            var hasdefault = child.data("select-hasdefault");
            if (hasdefault != "false") {
                child.append('<option value="">請選擇</option>');
            }

            //父級下拉有值時，ajax獲取數據
            if (select.val()) {var url = child.data('select-url') ? child.data('select-url') : '/DropdownList/Get' + child.attr("id");//url預設值
                var verb = child.data('verb') ? child.data('verb') : 'GET';//請求的方法

                var paramObj = {};//追加參數
                getParentSelectParam(selectid, paramObj)

                //追加控制參數
                var paramids = child.data('select-paramids');
                if (paramids) {
                    var paramidsArr = paramids.split(',')
                    for (var k = 0; k < paramidsArr.length; k++) {
                        paramObj[paramidsArr[k]] = $('#' + paramidsArr[k]).val();
                    }
                }

                $.ajax({
                    type: verb, url: url, data: paramObj, async: false,
                    contentype: "application/x-www-form-urlencoded; charset=UTF-8",
                    success: function (data) {
                        if (data) {
                            for (var j = 0; j < data.length; j++) {
                                var selected = data[j].value == childValue ? 'selected = "selected"' : '';
                                child.append('<option value="' + data[j].value + '" ' + selected + '>' + data[j].text + '</option>');
                            }
                        }
                    }
                });
            }

            //子級下拉如果還有下級,非初始化的時候 遞歸
            if (!isInit && child.data('select-childids'))
                getChildSelect(child.attr("id"));

        }
    }

    //遞歸獲取父級選中的值 param追加的url參數
    function getParentSelectParam(selectid, param) {
        var select = $("#" + selectid);
        param[selectid] = $(select).val();

        $('select[data-select-childids]').each(function () {
            var id = $(this).attr("id");
            if (selectid != id) {
                var childids = $(this).data('select-childids');
                if (childids) {
                    childidsArr = childids.split(',');
                    for (var i = 0; i < childidsArr.length; i++) {
                        if (childidsArr[i] == selectid) {
                            getParentSelectParam(id, param);//繼續向父級查找
                        }
                    }
                }
            }
        });
    }
});

後臺 action

 public class HomeController : Controller
    {
        private List<Area> areas;

        public HomeController()
        {
            areas = new List<Area>
            {
                new Area { Id = 1, Name = "中國", ParentId = null },
                new Area { Id = 2, Name = "美國", ParentId = null },
                new Area { Id = 3, Name = "江蘇省", ParentId = 1 },
                new Area { Id = 4, Name = "浙江省", ParentId = 1 },
                new Area { Id = 5, Name = "紐約州", ParentId = 2 },
                new Area { Id = 6, Name = "南京市", ParentId = 3 },
                new Area { Id = 7, Name = "杭州市", ParentId = 4 },
                new Area { Id = 8, Name = "紐約市", ParentId = 5 },
                new Area { Id = 9, Name = "曼哈頓區", ParentId = 8 },
                new Area { Id = 10, Name = "老廟區", ParentId = 6 },
                new Area { Id = 11, Name = "西湖區", ParentId = 7 }
            };
        }

        public IActionResult Index()
        {
            ViewBag.CountryList = areas.FindAll(x => x.ParentId == null).Select(x =>
                                                                         new SelectListItem
                                                                         {
                                                                             Value = x.Id.ToString(),
                                                                             Text = x.Name
                                                                         });

            return View(new UserModel());
        }

        public IActionResult Edit()
        {
            ViewBag.CountryList = areas.FindAll(x => x.ParentId == null).Select(x =>
                                                                         new SelectListItem
                                                                         {
                                                                             Value = x.Id.ToString(),
                                                                             Text = x.Name
                                                                         });

            return View(new UserModel() { CountryId = 2, PronviceId = 5, CityId=8,DistrictId = 9, LanguageId = 2 });
        }
    }

運行效果

用法說明

<a asp-action="Index" class="btn btn-success m-b-15">返回</a>
<br /><br />
<div class="form-inline row">
    <div class="form-group ">
        <label>國家</label>
        <select asp-for="CountryId" class="form-control selectList" asp-items="ViewBag.CountryList"
                data-select-childids="LanguageId,PronviceId">
            <option value="">請選擇</option>
        </select>
    </div>
    <div class="form-group ">
        <label>語言</label>
        <select asp-for="LanguageId" class="form-control"
                data-select-value="@Model.LanguageId"  
                data-select-url="/DropDownList/GetLanguageId?id=1" 
                data-select-paramids="CountryId"  
                data-select-hasdefault="false" 
                data-verb="Get" 請求的方式
                >
            <option value="">請選擇</option>
        </select>
    </div>
    <div class="form-group">
        <label>省</label>
        <select asp-for="PronviceId" class="form-control"
                data-select-childids="CityId"
                data-select-value="@Model.PronviceId"
                data-select-url="/DropDownList/GetPronviceId?id=1"
                data-select-paramids="CountryId"
                >
            <option value="">請選擇</option>
        </select>
    </div>
    <div class="form-group">
        <label>市</label>
        <select asp-for="CityId" class="form-control"
                data-select-childids="DistrictId"
                data-select-value="@Model.CityId"
                data-select-url="/DropDownList/GetCityId"
                data-select-paramids="PronviceId"
                >
            <option value="">請選擇</option>
        </select>
    </div>
    <div class="form-group">
        <label>區</label>
        <select asp-for="DistrictId" class="form-control"
                data-select-value="@Model.DistrictId"
                data-select-url="/DropDownList/GetDistrictId"
                >
            <option value="">請選擇</option>
        </select>
    </div>
</div>

data-select-childids ：設置聯動的select下拉的Id逗號分隔。例如在國家的下拉中 data-select-childids="LanguageId,PronviceId"表示，國家的下拉影響語言和省

data-select-value: 數據載入時的初始值用在編輯表單時,存儲當前下拉

data-select-url: 請求的url

data-select-paramids: 參數值的Id