c# - 如何在 asp.net mvc3 中显示错误消息

Question

请帮我在视图中显示错误消息。我的代码如下 -

这是我的视图模型：

public class DepartmentViewModel
{
    //public Department Department { get; set; }
    public string DepartmentId { get; set; }
    [Required]
    public string DepartmentName { get; set; }
    public string ManagerMemberId { get; set; }
    public bool IsActive { get; set; }
    public List<Member> Managers { get; set; } 
}

这是控制器：

public class DepartmentController : Controller
{
    //
    // GET: /Department/

    public ActionResult Index()
    {
        var adminUserId = (string)Session["UserId"];
        var memberId = (string)Session["MemberId"];

        List<Department> departments = null;

        if (!string.IsNullOrEmpty(adminUserId))
        {
            departments = new DepartmentManager().GetDepartments(false);
        }
        else if (!string.IsNullOrEmpty(memberId))
        {
            var companyId = (int)Session["CompanyId"];
            departments = new DepartmentManager().GetDepartments(false, companyId);
        }

        //var managers = new MemberManager().GetMembersOfManagerCategory(true, );

        return View("DepartmentList", departments);
    }


    public ActionResult Delete(string departmentId)
    {
        try
        {
            new DepartmentManager().DeleteDepartment(departmentId);
        }
        catch (System.Exception exception)
        {
            ModelState.AddModelError("Error", "Unable to delete department. Try again,      and if the problem persists see your system administrator.");
            //return RedirectToAction("Index", "Department");
        }

        return RedirectToAction("Index", "Department");
    }
}

这是视图：

@model IEnumerable<PDCA.Core.EntityClasses.Department>
@{
    ViewBag.Title = "Department List";
    Layout = "~/Views/Shared/_Layout.cshtml";
 }
<div class="container">
@using (Html.BeginForm())
{
    <form class="form-horizontal">
    <fieldset>
        <legend>List of Departments:</legend>
        <table border="1" cellspacing="1">
            <tr>
                <th>
                    Id
                </th>
                <th>
                    Name
                </th>
                <th>
                    Company
                </th>
                <th>
                    Manager
                </th>
                <th>
                    IsActive
                </th>
                <th>
                </th>
            </tr>
            @foreach (var item in Model)
            {
                <tr>
                    <td>
                        @Html.DisplayFor(modelItem => item.DepartmentId)
                    </td>
                    <td>
                        @Html.DisplayFor(modelItem => item.DepartmentName)
                    </td>
                    <td>
                        @Html.DisplayFor(modelItem => item.Company.CompanyName)
                    </td>
                    <td>
                        @Html.DisplayFor(modelItem => item.Manager.MemberName)
                    </td>
                    <td>
                        @Html.DisplayFor(modelItem => item.IsActive)
                    </td>
                    <td>
                        @Html.ActionLink("Edit", "Edit", new { item.DepartmentId }) |
                        @Html.ActionLink("Delete", "Delete", new { item.DepartmentId })
                    </td>
                </tr>
            }
        </table>
        <p></p>
        <p>
            @Html.ActionLink("Create New", "Create")
        </p>
        <p></p>
        <p>
            @Html.ValidationMessage("Error");
        </p>
    </fieldset>
    </form>
}

在视图中我放了 @Html.ValidationMessage("Error") 但错误消息没有显示在那里。

Answer 1

您正在重定向，因此 modelstate 消失了。您可以通过 tempdata 保存它，但我不会那样做（How do I maintain ModelState errors when using RedirectToAction?）。您可以使用特殊字段和一些通知消息（例如 toastr）来显示错误，或者只是停留在同一个视图上，然后会显示模型状态错误。

public ActionResult Delete(string departmentId)
    {
        try
        {
            new DepartmentManager().DeleteDepartment(departmentId);
        }
        catch (System.Exception exception)
        {
            ModelState.AddModelError("Error", "Unable to delete department. Try again,      and if the problem persists see your system administrator.");
            //return RedirectToAction("Index", "Department");
YOU SHOULD ADD MESSAGE TO VIEWDATA HERE, OR RETURN SAME VIEW(make delete POST action also)

        }
    return RedirectToAction("Index", "Department");
}

Answer 2

首先你有一个重复的表格

@using (Html.BeginForm())
{
    <form class="form-horizontal">

@Html.BeginForm为您处理form标签。

其次，尝试@Html.ValidationSummary像这样添加

@using (Html.BeginForm())
{
    @Html.ValidationSummary()
    <fieldset>

第三，您需要引用正确的脚本文件。通常这将在布局页面中完成，但这取决于您。

添加引用到

jquery
jquery.validate.js
jquery.validate.unobtrusive.j

CDN 可以在这里找到

假设您没有输入 a DepartmentName，请按提交，您应该会看到错误消息。

请记住，model您的页面必须是DepartmentViewModel. 在你上面的例子中它不是。

Answer 3

尝试按照@glosrob 的建议添加验证摘要，例如

@using (Html.BeginForm()) 
{
   @Html.ValidationSummary()
...

ValidationMessageFor也可以使用

<td>
     @Html.DisplayFor(modelItem => item.DepartmentName)
     @Html.ValidationMessageFor(v=>v.DepartmentName)
 </td>