Question

我不确定为什么我会收到此错误：

对象引用未设置为对象的实例。

我有一个包含一些组织的数据库，每个组织可以有多个域。我设置它的方法是只有一个常规的actionLink来删除一个域。这是代码的样子：

public ActionResult DeleteDomain(OrganizationDomainAddressView dd)
    {
        var org = OrganizationRepo.GetByID(dd.OrganizationID);
        if (ModelState.IsValid)
        {
            org.DomainAddresses.Remove(new OrganizationDomainAddress(dd.OrganizationID, dd.DomainAddress));
            OrganizationRepo.Delete(org);
        }
        OrganizationView orgInfo = (OrganizationView)Mapper.DynamicMap(org, typeof(Organization), typeof(OrganizationView));
        var domainList = orgInfo.DomainAddresses;
        var ACD = new OrganizationDomainAddressView();
        ViewData["ACD"] = ACD;
        ViewBag.OrganizationID = dd.OrganizationID;
        return PartialView("_EmailDomainPartial", domainList);
    }

以下是我正在使用的视图：

@model IEnumerable<AdminTool.Models.ViewModel.OrganizationDomainAddressView>
@using AdminTool.Models.ViewModel;
@{
OrganizationDomainAddressView ACD = (OrganizationDomainAddressView) ViewData["ACD"];
}

<div id="domains">
@foreach (var item in Model)
{
    <div class="item">
        @item.DomainAddress &mdash; @Html.ActionLink("Delete", "DeleteDomain", "Organizations", new { dd = item.DomainAddress })
    </div>
}
<div class="item">
    @Html.Hidden("OrganizationID", (int)ViewBag.OrganizationID)
</div>
@Html.Partial("_EmailDomainAddPartial", ACD)
</div>

和viewmodel：

public class OrganizationDomainAddressView
{
    public OrganizationDomainAddressView(string domainAddress, int organizationId)
    {
        DomainAddress = domainAddress;
        OrganizationID = organizationId;
    }

    public OrganizationDomainAddressView()
    { }

    [AtLeastOneRequired(ErrorMessageResourceType = typeof(AdminResource), ErrorMessageResourceName = "OrganizationEmailDomainRequired")]
    [Display(ResourceType = typeof(AdminResource), Name = "OrganizationValidEmailDomain")]
    [RegularExpression(@"@[a-z0-9.-]+\.[a-z]{2,4}", ErrorMessageResourceType = typeof(AdminResource), ErrorMessageResourceName = "OrganizationEmailFormatError")]
    public string DomainAddress { get; set; }

    public int OrganizationID { get; set; }
}

代码在控制器上错误输出：

org.DomainAddresses.Remove(new OrganizationDomainAddress(dd.OrganizationID, dd.DomainAddress));

不确定为什么会这样。任何帮助都会很棒！

Answer 1

根据引发错误的行，检查调试器以下代码部分是否为空：

组织
org.DomainAdresses

如果未设置dd，则错误将出现在上方的圆顶线上。根据您的实现，如果其中一个输入值为null，则OrganizationDomainAddress的构造函数可能会抛出NullReferenceException。

对象引用未设置为控制器上的对象错误的实例

1 个答案: