不显示删除回复显示所有回复显示星级回复显示得分回复 (急求高手解决)异常详细信息: System.ArgumentException: 已添加了具有相同键的项。

Question

已添加了具有相同键的项。  说明: 执行当前 Web 请求期间，出现未经处理的异常。请检查堆栈跟踪信息，以了解有关该错误以及代码中导致错误的出处的详细信息。  异常详细信息: System.ArgumentException: 已添加了具有相同键的项。源错误:  执行当前 Web 请求期间生成了未经处理的异常。可以使用下面的异常堆栈跟踪信息确定有关异常原因和发生位置的信息。   堆栈跟踪:  [ArgumentException: 已添加了具有相同键的项。]  System.ThrowHelper.ThrowArgumentException(ExceptionResource resource) +52  System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) +9383019  System.Linq.Enumerable.ToDictionary(IEnumerable`1 source, Func`2 keySelector, Func`2 elementSelector, IEqualityComparer`1 comparer) +252  System.Linq.Enumerable.ToDictionary(IEnumerable`1 source, Func`2 keySelector, IEqualityComparer`1 comparer) +91  System.Web.Mvc.ModelBindingContext.get_PropertyMetadata() +228  System.Web.Mvc.DefaultModelBinder.BindProperty(ControllerContext controllerContext, ModelBindingContext bindingContext, PropertyDescriptor propertyDescriptor) +392  System.Web.Mvc.DefaultModelBinder.BindProperties(ControllerContext controllerContext, ModelBindingContext bindingContext) +147  System.Web.Mvc.DefaultModelBinder.BindComplexElementalModel(ControllerContext controllerContext, ModelBindingContext bindingContext, Object model) +98  System.Web.Mvc.DefaultModelBinder.BindComplexModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +2501  System.Web.Mvc.DefaultModelBinder.BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +548  System.Web.Mvc.ControllerActionInvoker.GetParameterValue(ControllerContext controllerContext, ParameterDescriptor parameterDescriptor) +474  System.Web.Mvc.ControllerActionInvoker.GetParameterValues(ControllerContext controllerContext, ActionDescriptor actionDescriptor) +181  System.Web.Mvc.ControllerActionInvoker.InvokeAction(ControllerContext controllerContext, String actionName) +830  System.Web.Mvc.Controller.ExecuteCore() +136  System.Web.Mvc.ControllerBase.Execute(RequestContext requestContext) +111  System.Web.Mvc.ControllerBase.System.Web.Mvc.IController.Execute(RequestContext requestContext) +39  System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__4() +65  System.Web.Mvc.Async.<>c__DisplayClass1.<MakeVoidDelegate>b__0() +44  System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +42  System.Web.Mvc.Async.WrappedAsyncResult`1.End() +141  System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +54  System.Web.Mvc.Async.AsyncResultWrapper.End(IAsyncResult asyncResult, Object tag) +40  System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +52  System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +38  System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +8836977  System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +184 --------------------------------------------------------------------------------版本信息: Microsoft .NET Framework 版本:4.0.30319; ASP.NET 版本:4.0.30319.1  aspx代码：<h2>CreateRole</h2>  <%Html.BeginForm("CreateRole", "System", FormMethod.Post, new { enctype = "multipart/form-data" }); %>  <fieldset>  <table>  <tr>  <td align="right" width="10%">     <label for="roleID">roleID:</label>  </td>  <td>  <%= Html.TextBox("roleID")%>      </td>  </tr>  <tr>  <td align="right" width="10%">  <label for="companyID">companyID:</label>  </td>  <td>  <%= Html.TextBox("companyID")%>      </td>  </tr>  <tr>  <td align="right" width="10%">  <label for="roleCategoryID">roleCategoryID:</label>  </td>  <td>  <%= Html.TextBox("roleCategoryID")%>      </td>  </tr>  <tr>  <td align="right" width="10%">  <label for="roleCNm">roleCNm:</label>  </td>  <td>  <%= Html.TextBox("roleCNm")%>      </td>  </tr>  <tr>  <td align="right" width="10%">  <label for="roleENm">roleENm:</label>  </td>  <td>  <%= Html.TextBox("roleENm")%>      </td>  </tr>  <tr>  <td align="right" width="10%">  <label for="roleDescription">roleDescription:</label>  </td>  <td>  <%= Html.TextBox("roleDescription")%>      </td>  </tr>  <tr>  <td align="right" width="10%">  <label for="uUser">uUser:</label>  </td>  <td>  <%= Html.TextBox("uUser")%>      </td>  </tr>  <tr>  <td align="right" width="10%">  <label for="uDate">uDate:</label>  </td>  <td>  <%= Html.TextBox("uDate")%>      </td>  </tr>  </table>  <div>  <input type="submit" value="确认" />  <div style="float:right;">  <%: Html.ActionLink("Back to List", "Index") %>  </div>  </div>  </fieldset>  <%Html.EndForm(); %>Controllers代码:  [NoCache]  public ActionResult CreateRole()  {  Role role = new Role()    {  uDate = DateTime.Now.AddDays(7)  };  return View("CreateRole",role);  }  [HttpPost]  [NoCache]  public ActionResult CreateRole(Role role)  {  if (Session["UserName"] != null)  {  DB.Role.InsertOnSubmit(role);  DB.SubmitChanges();  return RedirectToAction("roleList");  }  else  {  return RedirectToAction("LogOn", "Account");  }  }每次点“确认”按钮时就会出现上面错误，那位高手帮帮忙，这个到底错在哪？非常感谢!

Answer 1

向键值对集合添加项时，判断是否已经存在了，如果没有则添加，存在则做修改等操作。