问题描述
这是我的级联下拉代码
<div class="form-group col-md-4">
<label asp-for="CarChassis.CompanyNameId" class="control-label"></label>
<select asp-for="CarChassis.CompanyNameId" class="form-control" asp-items="ViewBag.CompanyNameId"></select>
<span asp-validation-for="CarChassis.CompanyNameId" class="text-danger"></span>
</div>
<div class="form-group col-md-4">
<label asp-for="CarChassis.CarModelId" class="control-label"></label>
<select asp-for="CarChassis.CarModelId" class="form-control" asp-items="ViewBag.CarModelId"></select>
<span asp-validation-for="CarChassis.CarModelId" class="text-danger"></span>
</div>
和背后的代码
[BindProperty]
public CarChassis CarChassis { get; set; }
public int CarCompanyId { get; set; }
public SelectList CarModelsList { get; set; }
public async Task<IActionResult> OnGetAsync()
{
ViewData["CarModelId"] = new SelectList(_context.CarModels,"Id","Name");
ViewData["CompanyNameId"] = new SelectList(_context.CompanyNames,"Name");
ViewData["CreateYearId"] = new SelectList(_context.CreateYears,"Name");
ViewData["diversityId"] = new SelectList(_context.diversity,"Name");
return Page();
}
public JsonResult OnGetCarMode(int CarCompanyI)
{
var CarModelsList = _context.CarModels.Where(x => x.CompanyNameId == CarCompanyI).ToListAsync();
return new JsonResult(CarModelsList);
}
这也是我的模特
public class CompanyName
{
public string Name { get; set; }
public DateTime CreateDate { get; set; }
public DateTime ModifyDate { get; set; }
public ICollection<CarModel> CarModels { get; set; }
}
public int Id { get; set; }
public string Name { get; set; }
public DateTime CreateDate { get; set; }
public DateTime ModifyDate { get; set; }
public int CompanyNameId { get; set; }
public CompanyName CompanyName { get; set; }
}
这是我的ajax代码
<script>
$(function () {
$("#CarChassis_CompanyNameId").on("change",function () {
var CarCompanyI = $(this).val();
$("#CarChassis_CarModelId").empty();
$("#CarChassis_CarModelId").append("<option value=''>select </option>");
$.getJSON(`?handler=CarMode&CarCompanyI=${CarCompanyI}`,(data) => {
$.each(data,function (i,item) {
$("#SubCategoryId").append("<option value='"+ item.id+ "'>" + item.name + "</option>");
});
});
});
});
</script>
解决方法
您的代码中有两个问题。
第一个在您的代码中(这不是异步方法,不能使用 ToListAsync
):
var CarModelsList = _context.CarModels.Where(x => x.CompanyNameId == CarCompanyI).ToListAsync();
改为:
var CarModelsList = _context.CarModels.Where(x => x.CompanyNameId == CarCompanyI).ToList();
第二个在您的 ajax 中(SubCategoryId
不存在)。
$.each(data,function (i,item) {
$("#SubCategoryId").append("<option value='"+ item.id+ "'>" + item.name + "</option>");
});
改为:
$.each(data,item) {
$("#CarChassis_CarModelId").append("<option value='"+ item.id+ "'>" + item.name + "</option>");
});