HTML.Partial() 在显示时不起作用？

Question

在 Asp.net mvc 5 中，我们有一个登录页面，它实现 HTML.BeginForm() 以将数据发布到控制器，如果用户名和密码不正确，我们将使用部分视图将错误发送回前端。一切正常，如果出现错误，屏幕上只会显示错误消息，没有其他内容。

控制器

[HttpPost]
public ActionResult SingleSSOMPLogin(SSoStateModel model)
{
    //Check the Code with SP providers and Authorization server.
      if(model.SAMLAssertion.validMPData)
      {
        return RedirectToAction("SSOServiceMP" , "SAML");
      }else
      { 
         //Error message processed.
         model.errorMessage = SSOState.SAMLAssertion.errorMessage;
         return PartialView("_LoginError" , model);
      }
}

视图包含以下代码

<div class="peripheral">
        <div class="panel panel-default panel-peripheral">
            @{Html.Partial("_LoginError", Model);}
            <div class="panel-heading clearfix">Please Log In</div>
            <div class="panel-body">
                <div class="brand-logo eop-logo">
                    <script type="text/javascript">
                        function changeImage() {
                            document.getElementById("Logo").src = '@Url.Content("~/Content/images/TopLogo.gif")';
                        }
                    </script>
                    <img id="Logo" width="200" src='@Url.Content("~/Content/images/TopLogo.gif")' onerror="changeImage()" />


                    @{ Html.EnableClientValidation(true);}

                    <!--Ajax call to Controller-->
                    @using (Html.BeginForm("SingleSSOMPLogin", "Accounts"))
                    {
                        @Html.ValidationSummary(true);

                        <div id="group-email" class="form-group col-md-12 ">
                            @Html.TextBoxFor(m => m.Email, new { @class = "form-control", placeholder = "Please enter your Email address" })
                            @Html.ValidationMessageFor(m => m.Email)
                        </div>

                        <div id="group-password" class="form-group col-md-12">
                            @Html.PasswordFor(m => m.Password, new { @class = "form-control", placeholder = "Please enter your password" })
                            @Html.ValidationMessageFor(m => m.Password)
                        </div>

                        <div class="form-group">
                            <div class="col-md-12">
                                <button type="submit" class="btn btn-primary pull-left">Login</button>
                                <a id="forgot" href='@Url.Action("ForgotPassword","Accounts")' class="btn btn-link btn-sm pull-right">Forgot your password?</a>
                            </div>
                        </div>
                    }
                </div>
            </div>
        </div>
    </div>

局部视图

@{
    Layout = null;
}

@if (Model.Result!= null)
{
    <div class="alert alert-warning alert-dismissable">
        <button type="button" class="close" data-dismiss="alert" aria-hidden="true">&times;</button>
        <strong>@Model.Result.errorMessage</strong>
    </div>
}

发生错误时，我会再次重定向到同一个视图，所有查询参数都消失了，只显示错误消息。

如何解决以下问题？

Answer 1

局部视图将只返回您定义的片段。 因此，当从“完整”视图调用时，

@{Html.Partial("_LoginError", Model);}

它将生成视图的相应部分。

在您的情况下，最常见的是添加模型错误并返回完整视图（必须具有 ValidationSummary 部分）：

[HttpPost]
public ActionResult SingleSSOMPLogin(SSoStateModel model)
{
    //Check the Code with SP providers and Authorization server.
      if(model.SAMLAssertion.validMPData)
      {
        return RedirectToAction("SSOServiceMP" , "SAML");
      }else
      { 
         //Error message processed.
         ModelState.AddModelError("error", SSOState.SAMLAssertion.errorMessage);             
         return View(model);
      }
}

如果您想使用局部视图，您必须从 javacript ajax 调用中调用它并将响应插入到您的页面中。使用 jQuery，它或多或少类似于：

$.ajax({ url: <partial view url>,
         type: 'GET',
         success: function (result) {
           $(updateSelector).hide().html(result).effect("fade", "fast");
         }
      });