级联下拉列表与Json固定的Guid Id

本文关键字：Guid Id 下拉列表 Json 级联 | 更新日期: 2023-09-27 18:02:42

大家好，我需要修复一个级联下拉列表与Guid Id工作…使用Int Id可以正常工作…但是我需要在我的表上使用Guid Id。

当我将类型更改为Guid(在我的模型和数据库上)…它不会填充下拉列表

请帮忙解决这个问题

I got this:

控制器

  public JsonResult GetCountries()
    {           
        return Json(countries.GetAll().ToList(), JsonRequestBehavior.AllowGet);            
    }

  public JsonResult GetStatesByCountryId(string countryId)
    {     
//I know, I have to convert to Guid here... the problem is in the first dropdownlist       
        int Id = Convert.ToInt32(countryId);
        var states = from s in state.GetAll() where s.CountryId == Id select s;
        return Json(states);
    }
<<p> 视图/strong> 
    <div>
        @Html.DropDownList("dropdownCountry", new SelectList(string.Empty, "Value", "Text"), "Please select a country", new { @style = "width:250px;" })
    </div>
    <div style="margin-top:50px;">
        @Html.DropDownList("dropdownState", new SelectList(string.Empty, "Value", "Text"), "Please select a state", new { @style = "width:250px;" })
    </div>
</div>
<!-- jQuery -->
<script src="~/Assets/vendors/jquery/dist/jquery.min.js"></script>
<!-- Bootstrap -->
<script src="~/Assets/vendors/bootstrap/dist/js/bootstrap.min.js"></script>

    <script type="text/javascript">
    $(function () {
        $.ajax({
            type: "GET",
            url: "/Home/getcountries",
            datatype: "Json",            
            success: function (data) {
                $.each(data, function (index, value) {
//I think the problem is here it doesn't read Guid Numbers...when CountryId is a Guid
                    $('#dropdownCountry').append('<option value="' + value.CountryId + '">' + value.CountryName + '</option>'); 
                });
            }
        });
        $('#dropdownCountry').change(function () {
            $('#dropdownState').empty();
            $.ajax({
                type: "POST",
                url: "/Home/GetStatesByCountryId",
                datatype: "Json",
                data: { countryId: $('#dropdownCountry').val() },
                success: function (data) {
                    $.each(data, function (index, value) {
                        $('#dropdownState').append('<option value="' + value.Id + '">' + value.StateName + '</option>');
                    });
                }
            });
        });
    });
    </script>

级联下拉列表与Json固定的Guid Id

如果将实体模型/db中的Id类型更改为Guid，则下面一行将失败

public JsonResult GetStatesByCountryId(string countryId)
{            
    int Id = Convert.ToInt32(countryId);
}

转换。ToInt32需要一个可以转换为有效int的对象(例如:"123")。但是Guid就像"49e17a97-88ce-4acc-8aba-ae0c8740fd5d"一样，不能转换为int。所以只要使用Guid作为参数。

public JsonResult GetStatesByCountryId(Guid countryId)
{ 
    var states = (from s in state.GetAll() where s.CountryId == countryId  
                                                               select s).ToList();   
    return Json(states, JsonRequestBehavior.AllowGet);
}

假设state.GetAll方法返回一个项目集合，其中它具有Guid类型的CountryId属性。(并且状态id也是Guids)

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