如何根据级联下拉列表选择的值从数据库中获取属性值？

Question

I want to get a property of an entity based on passing id's of selected items from cascaded dropdown list...On every change in level 1 or in level 2 of cascaded drop down list, price must be updated.

我实现了级联下拉列表。在页面加载时 Leaguedropdown（级别 1） 填充和第二个 LeagueDivisiondropdown（级别 2） 当我 select 来自级别 1 的任何项目时填充。我必须实施 价格计算器，它应该根据级联下拉列表中的 selected 项目计算价格值，所有价格都存储在数据库中，我正在使用 Entity Framework. 我正在使用 .change() 方法并发送工作正常的 2 级 getJson 请求。我也想在级别 1 上使用相同的功能，但我已经使用 .change() 方法来填充 LeagueDivision，所以我也不知道如何在级别 1 上实现它。

如有高人指点，将不胜感激

这是视图和脚本

<body>
<p id="message"></p>
@using (Html.BeginForm("PriceCalculatorIndex", "PriceCalculator", FormMethod.Post,
                                      new { enctype = "multipart/form-data" }))
{

    <div>
        @Html.LabelFor(m => m.SelectedLeague, new { @class = "control-lebel" })
        @Html.DropDownListFor(m => m.SelectedLeague, Model.LeagueList, new { @class = "form-control" })
        @Html.ValidationMessageFor(m => m.SelectedLeague)
    </div>
    <div>
        @Html.LabelFor(m => m.SelectedLeagueDivision, new { @class = "control-lebel" })
        @Html.DropDownListFor(m => m.SelectedLeagueDivision, Model.LeagueDivisionList, new { @class = "form-control" })
        @Html.ValidationMessageFor(m => m.SelectedLeagueDivision)
    </div>
    <div>
        @Html.LabelFor(m => m.Price)
        @Html.DisplayFor(m => m.Price)
    </div>
}
<!-- JS includes -->
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script src="//netdna.bootstrapcdn.com/bootstrap/3.1.1/js/bootstrap.min.js"></script>
<script src="//ajax.aspnetcdn.com/ajax/jquery.validate/1.11.1/jquery.validate.min.js"></script>
<script src="//ajax.aspnetcdn.com/ajax/mvc/4.0/jquery.validate.unobtrusive.min.js"></script>
<script type="text/javascript">
    var leaguedivisionUrl = '@Url.Action("Fetchleaguedivision")';
    var updatePrice = '@Url.Action("updatePrice")';
    var divisions = $('#SelectedLeagueDivision');
    $('#SelectedLeague').change(function () {
        divisions.empty();
        $.getJSON(leaguedivisionUrl, { ID: $(this).val() }, function (data) {
            if (!data) {
                return;
            }
            divisions.append($('<option></option>').val());
            $.each(data, function (index, item) {
                divisions.append($('<option></option>').val(item.Value).text(item.Text));
            });
        });
    });

    $('#SelectedLeagueDivision').change(function () {

        $.getJSON(updatePrice, { LeagueDivisionId: $(this).val(), LeagueId: $('#SelectedLeague').val() }, function (data) {
            if (!data) {
                return;
            }
            alert(data);
            //document.getElementById('#message').innerHTML = data;
        });
    });
</script>

JSON 从数据库中获取价格的结果

 public JsonResult updatePrice(int LeagueId, int LeagueDivisionId)
    {

        HostBoostersDBEntities2 db = new HostBoostersDBEntities2();
        CalculatorPrice updatedPrice = db.CalculatorPrices
           .Where(x => x.LeagueId == LeagueId
               &&
               x.LeagueDivisionId == LeagueDivisionId)
               .FirstOrDefault();
        decimal updatedPriceToView = (decimal)updatedPrice.Price;
        return Json(updatedPriceToView.ToString(), JsonRequestBehavior.AllowGet);
    }

Answer 1

请尝试此代码。参考我的 javascript 评论，你认为我仍然误解了这个问题。

<script type="text/javascript">
    var leaguedivisionUrl = '@Url.Action("Fetchleaguedivision")';
    var updatePrice = '@Url.Action("updatePrice")';
    var divisions = $('#SelectedLeagueDivision');

    function bindLeagueDivisionData(data) {
        divisions.empty();
        $.each(data, function(index, item) {
            divisions.append($('<option></option>').val(item.Value).text(item.Text));
        });
    }

    function getUpdatedPrice(leagueId, divisionId) {
        $.getJSON(updatePrice, {
            LeagueDivisionId: divisionId,
            LeagueId: leagueId
        }, function(data) {
            if (!data) {
                return;
            }
            alert(data);
            //document.getElementById('#message').innerHTML = data;
        });
    }

    $('#SelectedLeague').change(function() {
        if (divisions.find("option").length == 0) {
            /*The division list is empty, fetch the divisions*/
            $.getJSON(leaguedivisionUrl, {
                ID: $(this).val()
            }, function(data) {
                if (!data) {
                    return;
                }
                /*Once division data is bound, get the price for the league and first selected division. If you choose to leave first division as empty, your wish; just remove the contents of done in that case*/
                $.when(bindLeagueDivisionData(data)).done(function() {
                    getUpdatedPrice($(this).val(), $('#SelectedLeagueDivision'));
                });
            });
        } else {
            /*Divisions are already present just get the price for the combination*/
            getUpdatedPrice($(this).val(), $('#SelectedLeagueDivision'));
        }
    });

    $('#SelectedLeagueDivision').change(function() {
        /*Get the price for the combination*/
        getUpdatedPrice($('#SelectedLeague').val(), $(this).val());
    });
</script>

Answer 2

I have implemented successfully in this way.

@using (Html.BeginForm("PriceCalculatorIndex", "PriceCalculator", FormMethod.Post,
                                      new { enctype = "multipart/form-data" }))
{

    <div>
        @Html.LabelFor(m => m.SelectedLeague, new { @class = "control-lebel" })
        @Html.DropDownListFor(m => m.SelectedLeague, Model.LeagueList, new { @class = "form-control" })
        @Html.ValidationMessageFor(m => m.SelectedLeague)
    </div>
    <div>
        @Html.LabelFor(m => m.SelectedLeagueDivision, new { @class = "control-lebel" })
        @Html.DropDownListFor(m => m.SelectedLeagueDivision, Model.LeagueDivisionList, new { @class = "form-control" })
        @Html.ValidationMessageFor(m => m.SelectedLeagueDivision)
    </div>
    <div>
        <label>
            price :
        </label>
        <span id="spPrice"></span>
    </div>
}
<!-- JS includes -->
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script src="//netdna.bootstrapcdn.com/bootstrap/3.1.1/js/bootstrap.min.js"></script>
<script src="//ajax.aspnetcdn.com/ajax/jquery.validate/1.11.1/jquery.validate.min.js"></script>
<script src="//ajax.aspnetcdn.com/ajax/mvc/4.0/jquery.validate.unobtrusive.min.js"></script>
<script type="text/javascript">
    $(function () {
        LoadDivisionsAndPrice()
    });
    var leaguedivisionUrl = '@Url.Action("Fetchleaguedivision")';
    var updatePrice = '@Url.Action("updatePrice")';
    var divisions = $('#SelectedLeagueDivision');
    $('#SelectedLeague').change(function () {
        LoadDivisionsAndPrice();
    });
    $('#SelectedLeagueDivision').change(function () {
        LoadPrice();
    });
    function LoadPrice() {
        $.getJSON(updatePrice, { LeagueId: $('#SelectedLeague').val(), LeagueDivisionId: $('#SelectedLeagueDivision').val() }, function (data) {
            if (!data) {
                return;
            }
            document.getElementById('spPrice').innerText = data.Price;
        });
    }
    function LoadDivisionsAndPrice()
    {
        divisions.empty();
        $.getJSON(leaguedivisionUrl, { ID: $('#SelectedLeague').val() }, function (data) {
            if (!data) {
                return;
            }
            divisions.append($('<option></option>').val());
            $.each(data, function (index, item) {
                divisions.append($('<option></option>').val(item.Value).text(item.Text));
            });
            LoadPrice();
        });
    }        
</script>

如何根据级联下拉列表选择的值从数据库中获取属性值？

How to get a property value from database based on cascaded drop down list selected values??

javascript

c#

asp.net-mvc

jquery

getjson

如何根据级联下拉列表选择的值从数据库中获取 属性 值？

How to get a property value from database based on cascaded drop down list selected values??

javascript

c#

asp.net-mvc

jquery

getjson

如何根据级联下拉列表选择的值从数据库中获取属性值？