[英]cascading dropdown razor pages
這是我的級聯下拉代碼
<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>
和后面的代碼
[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, "Id", "Name");
ViewData["CreateYearId"] = new SelectList(_context.CreateYears, "Id", "Name");
ViewData["DiversityId"] = new SelectList(_context.Diversity, "Id", "Name");
return Page();
}
public JsonResult OnGetCarMode(int CarCompanyI)
{
var CarModelsList = _context.CarModels.Where(x => x.CompanyNameId == CarCompanyI).ToListAsync();
return new JsonResult(CarModelsList);
}
這也是我的模特
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; }
}
這是我的 ajax 代碼
<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>
運行我的代碼后,我收到此錯誤
未捕獲的類型錯誤:無法讀取 null 的屬性“id”
您的代碼中有兩個問題。
第一個在您的代碼中(這不是異步方法,不能使用ToListAsync
):
var CarModelsList = _context.CarModels.Where(x => x.CompanyNameId == CarCompanyI).ToListAsync();
將其更改為:
var CarModelsList = _context.CarModels.Where(x => x.CompanyNameId == CarCompanyI).ToList();
第二個在您的 ajax 中( SubCategoryId
不存在)。
$.each(data, function (i, item) {
$("#SubCategoryId").append("<option value='"+ item.id+ "'>" + item.name + "</option>");
});
將其更改為:
$.each(data, function (i, item) {
$("#CarChassis_CarModelId").append("<option value='"+ item.id+ "'>" + item.name + "</option>");
});
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.