如何绑定JSON数据使用jQuery在Asp.net MVC为DropDownList

问题描述

我试图绑定JSON数据到下拉列表

I am trying to bind JSON Data to dropdown list

我的情况是我想要得到的数据并绑定到动态的下拉列表中，

My Scenario is I want to get data and Bind to dynamic dropdown list,

在独立的类，我已经使用LINQ获得像

In Seperate Class, I have used linq to get data like

    public SelectList getProjects()
    {
        IEnumerable<SelectListItem> projectslist = (from proj in res.PROJECTs where proj.IS_DELETED == "N" select proj).AsEnumerable().Select(projt => new SelectListItem() { Text = projt.NAME, Value = projt.ID.ToString() });
        return new SelectList(projectslist, "Value", "Text", PROJ_ID);
    }

在控制器：

ViewBag.ProjectList=(from proj in res.PROJECTs where proj.IS_DELETED == "N" select proj).AsEnumerable().Select(projt => new SelectListItem() { Text = projt.NAME, Value = projt.ID.ToString() });

在View：

    @for (int i = 0; i <2; i++)
    {                                    {
   @Html.DropDownListFor(m => m.GetTimeSheetDetails[i].PROJ_ID, (SelectList)ViewBag.ProjectList, "-- Choose a Project --", new { @class = "ddlProjectvalue" })
    }

现在，我尝试了一样，如果我们有三个DropDownList中，我们选择第一个下拉列表中的列表项不应该在第二个下拉列表中显示，而在第三个下拉列表中不应该显示为previous选择列表项我已经writtern像脚本：

Now, I am trying for like if we have three dropdownlist, we select a list item in first dropdown list should not show in second dropdown list, and in third dropdown list should not show both previous selected list items for that i have writtern script like:

     <script>
    $(document).ready(function () {
        $('.ddlProjectvalue').change(function () {
            debugger;
            var selectedValue = $(this).val();
            if (selectedValue != null && selectedValue != '') {
                debugger;
                $.ajax({

                    type: "GET",
                    contentType: "application/json; charset=utf-8",
                    url: "/Employer/GetDDLData?selectedValue="+selectedValue,
                    data: "{}",
                    dataType: "Json",
                    success: function (data) {

                        // first remove the current options if any
                        $('.ddlProjectvalue').find('option').remove();

                        // next iterate thru your object adding each option to the drop down\
                        $(data).each(function (index, item) { // GETTING ERROR HERE
                            debugger;

                            $('.ddlProjectvalue').append($('<option></option>').val(item.Value).html(item.Text));
                        });
                    },
                    error: function ajaxError(response) {
                    alert(response.status + ' ' + response.statusText);
                }
            });
        }
      });
    });
   </script>

和我从控制器返回JSON数据：

and I am returning JSON Data from Controller:

    public ActionResult GetDDLData(string selectedValue)
    {
        int projectid = Convert.ToInt32(selectedValue);

        IEnumerable<SelectListItem> projectslist = (from proj in db.PROJECTs where proj.IS_DELETED == "N" && proj.ID != projectid select proj).AsEnumerable().Select(projt => new SelectListItem() { Text = projt.NAME, Value = projt.ID.ToString() });
        var result = new SelectList(projectslist, "Value", "Text", tm.PROJ_ID);
        return Json(result, JsonRequestBehavior.AllowGet);
    }

我都试过了，但得到错误像

I have tried, but getting Error like

      "Syntax error, Unrecognized Expression"

我在哪里的错误行为，请帮助我的人。

where I am Doing Wrong , please help me anyone.

推荐答案

这将帮助您：

$.ajax({
            url: "@Url.Action("GetDDLData","Employer")",
            data: {selectedValue:selectedValue},
            dataType: "json",
            type: "GET",
            error: function () {
                alert(" An error occurred.");
            },
            success: function (data) {
                var optionhtml1 = '<option value="' +
                 0 + '">' + "--Select State--" + '</option>';
                $(".ddlProjectvalue").append(optionhtml1);

                $.each(data, function (i) {

                    var optionhtml = '<option value="' +
                data[i].Value + '">' +data[i].Text + '</option>';
                    $(".ddlProjectvalue").append(optionhtml);
                });
            }
        });

这篇关于如何绑定JSON数据使用jQuery在Asp.net MVC为DropDownList的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！