C# 通过ajax将表单字段的值从视图传递给控制器,并根据状态选择填充下拉列表
我正在尝试创建一个州和城市下拉列表。当选择州时,城市将进行填充。我使用ajax来实现这一点。我把所有的东西都写下来了,我觉得应该行得通,当然不行。“州”下拉列表是从一个单独的类中提取的,该类包含美国所有50个州的可枚举列表。作为我在控制器中编写的第二个下拉列表,我希望能够返回Json数据来填充城市下拉列表。 这是我的dropdownlistfor剃须刀以及我的jquery和ajax:C# 通过ajax将表单字段的值从视图传递给控制器,并根据状态选择填充下拉列表,c#,jquery,ajax,asp.net-mvc,C#,Jquery,Ajax,Asp.net Mvc,我正在尝试创建一个州和城市下拉列表。当选择州时,城市将进行填充。我使用ajax来实现这一点。我把所有的东西都写下来了,我觉得应该行得通,当然不行。“州”下拉列表是从一个单独的类中提取的,该类包含美国所有50个州的可枚举列表。作为我在控制器中编写的第二个下拉列表,我希望能够返回Json数据来填充城市下拉列表。 这是我的dropdownlistfor剃须刀以及我的jquery和ajax: <div class="form-group"> @Html.LabelFo
<div class="form-group">
@Html.LabelFor(model => model.State, htmlAttributes: new { @class = "control-label col-md-2" })
<div class="col-md-10">
@Html.DropDownListFor(model => model.State, WebGridProject.Models.StateCodes.GetStatesList(), new { id = "State", @class = "form-control", @onchange = "FillCity2()" })
@Html.ValidationMessageFor(model => model.State, "", new { @class = "text-danger" })
</div>
</div>
<script>
function FillCity2() {
var stateId = $('#State').val();
console.log(stateId);
$.ajax({
url: '/Home/FillCity2',
type: "GET",
dataType: "JSON",
data: { State: stateId },
success: function (city) { // cities is the variable in the controller made to fetch the city list
$("#City").html("");
$.each(city, function (i , cityNames) {
$("#City").append(
$('<option></option>').val(cityNames.cities));
});
}
});
}
</script>
<div class="form-group">
@Html.LabelFor(model => model.City, htmlAttributes: new {@class = "control-label col-md-2"})
<div class="col-md-10">
@Html.DropDownListFor(model => model.City, new SelectList(Enumerable.Empty<SelectListItem>()), "Select City", new { id = "City", @class = "form-control"})
@Html.ValidationMessageFor(model => model.City, "", new {@class = "text-danger"})
</div>
</div>
@LabelFor(model=>model.State,htmlAttributes:new{@class=“controllabel col-md-2”})
@Html.DropDownListFor(model=>model.State,WebGridProject.Models.StateCodes.GetStatesList(),new{id=“State”,@class=“form control”,@onchange=“FillCity2()”})
@Html.ValidationMessageFor(model=>model.State,“,new{@class=“text danger”})
函数FillCity2(){
var stateId=$('#State').val();
console.log(stateId);
$.ajax({
url:“/Home/FillCity2”,
键入:“获取”,
数据类型:“JSON”,
数据:{State:stateId},
成功:函数(city){//cities是控制器中用于获取城市列表的变量
$(“#城市”).html(“”);
$。每个(城市,功能(i,城市名称){
$(“#城市”)。追加(
$('').val(cityNames.cities));
});
}
});
}
@LabelFor(model=>model.City,htmlAttributes:new{@class=“controllabel col-md-2”})
@Html.DropDownListFor(model=>model.City,new SelectList(Enumerable.Empty()),“Select City”,new{id=“City”,@class=“form control”})
@Html.ValidationMessageFor(model=>model.City,“,new{@class=“text danger”})
以下是我用来处理请求的控制器操作:
public JsonResult FillCity2(string stateName)
{
List<SelectListItem> cities = new List<SelectListItem>();
switch (stateName)
{
case "AK":
cities = new List<SelectListItem>
{
new SelectListItem() {Text = "", Value = ""},
new SelectListItem() {Text = "Anchorage", Value = "Anchorage"},
new SelectListItem() {Text = "Fairbanks", Value = "Fairbanks"},
};
break;
case "AL":
cities = new List<SelectListItem>
{
new SelectListItem() {Text = "", Value = ""},
new SelectListItem() {Text = "Auburn", Value = "Auburn"},
new SelectListItem() {Text = "Birmingham", Value = "Birmingham"},
new SelectListItem() {Text = "Dothan", Value = "Dothan"},
new SelectListItem() {Text = "Mobile", Value = "Mobile"},
};
break;
case "AZ":
cities = new List<SelectListItem>
{
new SelectListItem() {Text = "", Value = ""},
new SelectListItem() {Text = "Pheonix", Value = "Pheonix"},
new SelectListItem() {Text = "Flagstaff", Value = "Flagstaff"},
new SelectListItem() {Text = "Prescott", Value = "Prescott"},
new SelectListItem() {Text = "Tucson", Value = "Tucson"},
};
break;
case "AR":
cities = new List<SelectListItem>
{
new SelectListItem() {Text = "", Value = ""},
new SelectListItem() {Text = "Fayetteville", Value = "Fayetteville"},
new SelectListItem() {Text = "Fort smith", Value = "Fort smith"},
new SelectListItem() {Text = "Jonesboro", Value = "Jonesboro"},
new SelectListItem() {Text = "Texarkana", Value = "Texarkana"},
};
break;
default:
cities = new List<SelectListItem>
{
new SelectListItem() {Text = "", Value = ""},
new SelectListItem() {Text = "Please Select State", Value = "Please Select State"},
};
break;
}
return Json(cities, JsonRequestBehavior.AllowGet);
}
public JsonResult FillCity2(字符串stateName)
{
列表城市=新列表();
交换机(stateName)
{
案例“AK”:
城市=新列表
{
新建SelectListItem(){Text=”“,Value=”“},
新建SelectListItem(){Text=“Anchorage”,Value=“Anchorage”},
新建SelectListItem(){Text=“Fairbanks”,Value=“Fairbanks”},
};
打破
案例“AL”:
城市=新列表
{
新建SelectListItem(){Text=”“,Value=”“},
新建SelectListItem(){Text=“Auburn”,Value=“Auburn”},
新建SelectListItem(){Text=“Birmingham”,Value=“Birmingham”},
新建SelectListItem(){Text=“Dothan”,Value=“Dothan”},
新建SelectListItem(){Text=“Mobile”,Value=“Mobile”},
};
打破
案例“AZ”:
城市=新列表
{
新建SelectListItem(){Text=”“,Value=”“},
新建SelectListItem(){Text=“Pheonix”,Value=“Pheonix”},
新建SelectListItem(){Text=“Flagstaff”,Value=“Flagstaff”},
新建SelectListItem(){Text=“Prescott”,Value=“Prescott”},
新建SelectListItem(){Text=“Tucson”,Value=“Tucson”},
};
打破
案例“AR”:
城市=新列表
{
新建SelectListItem(){Text=”“,Value=”“},
新建SelectListItem(){Text=“Fayetteville”,Value=“Fayetteville”},
新建SelectListItem(){Text=“Fort smith”,Value=“Fort smith”},
新建SelectListItem(){Text=“Jonesboro”,Value=“Jonesboro”},
新建SelectListItem(){Text=“Texarkana”,Value=“Texarkana”},
};
打破
违约:
城市=新列表
{
新建SelectListItem(){Text=”“,Value=”“},
新建SelectListItem(){Text=“请选择状态”,Value=“请选择状态”},
};
打破
}
返回Json(cities,JsonRequestBehavior.AllowGet);
}
当我在调试器中运行时,#State的值显示为null,尽管在chrome的控制台中它显示了实际值(例如,阿拉巴马州的“AL”,阿拉斯加的“AK”,等等)
我不太明白我传递值的问题在哪里。调试器中的城市列表只会一直转到默认的开关情况
有什么想法吗?您的操作方法参数名和ajax调用数据参数名应该匹配。由于ajax调用在名为
state
的参数中发送选定的状态值,因此您应该更新操作方法,使其具有相同的状态值(或以其他方式)
此外,您的操作方法还返回一个
SelectListItem
列表,该列表具有Text
和Value
属性。因此,在构建城市下拉列表时,您应该使用这些属性中的任何一个。但是您正在尝试访问列表中不存在的每个项目的cities
属性
最后,您需要设置选项的文本
,以及值。因为文本是w
public JsonResult FillCity2(string state)
{
//use the state variable in your method now for switch statement
}
success: function (cityArray) {
$("#City").html("");
$.each(cityArray, function (i, city) {
$("#City").append(
$('<option></option>').val(city.Value).text(city.Text));
});
}
data: { stateName: stateId },
data: { State: stateId },
success: function (stateCities) {
var cities = document.getElementById('City');
while (cities.options.length) {
cities.remove(0);
}
$.each(stateCities, function(i, city) {
cities.add(new Option(city.Value, city.Text));// or whatever the correct properties are
});
}