Html '；已添加具有相同密钥的项'；

我正试图通过此表单向数据库发送一些数据。我不断收到关于已添加具有相同密钥的项的错误

我已经尝试调试这个错误很长一段时间了。我确实有几个元素被他们的@Html助手赋予了相同的名称，但我想我已经清除了它们

<div id="addNewUser" class="newUser" style="border: solid black 2px">
    <form name="newUser" method="post" action="@Url.Action("Submit", "Roles")">
        <h4>Add New User</h4>
        <div style="display: flex; justify-content: space-between">
            <div id="ddlNewUserHealthPlan" class="form-group">
                @Html.DropDownListFor(m => m.NewUserHealthPlans, (IEnumerable<SelectListItem>)Model.GetHealthPlans(Model.HEALTHPLAN), "Select a Healthplan", new { @class = "form-group", @id = "ddlNewUserHealthPlanSelect" })
            </div>
            <div id="ddlNewUserRoles" class="form-group">
                @Html.DropDownListFor(m => m.Roles, (IEnumerable<SelectListItem>)Model.GetUserRoles(Model.USERROLE), "Select a Role", new { @class = "form-group", @id = "ddlNewUserRoleSelect" })
            </div>
        </div>
        <div style="display: flex; justify-content: space-between">
            <div class="form-group">
                @Html.Label("User Id: ")
                @Html.TextBoxFor(m => m.User_Id, new { @class = "form-control" })
            </div>
            <div id="ddlNewUserPrimaryHP" class="form-group">
                @Html.DropDownListFor(m => m.NewUserPrimaryHealthPlan, (IEnumerable<SelectListItem>)Model.GetHealthPlans(Model.HEALTHPLAN), "Select a Primary Healthplan", new { @class = "form-group", @id = "newUserPrimaryHP" })
            </div>
        </div>


        <br />
        <div style="display: flex; justify-content:center">
            <button type="submit" class="btn btn-primary">Add new User</button>
        </div>

    </form>
</div>

堆栈跟踪

[ArgumentException: An item with the same key has already been added.]
   System.ThrowHelper.ThrowArgumentException(ExceptionResource resource) +52
   System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) +13007142
   System.Collections.Generic.CollectionExtensions.ToDictionaryFast(TValue[] array, Func`2 keySelector, IEqualityComparer`1 comparer) +116
   System.Web.Mvc.ModelBindingContext.get_PropertyMetadata() +149
   System.Web.Mvc.DefaultModelBinder.BindProperty(ControllerContext controllerContext, ModelBindingContext bindingContext, PropertyDescriptor propertyDescriptor) +176
   System.Web.Mvc.DefaultModelBinder.BindProperties(ControllerContext controllerContext, ModelBindingContext bindingContext) +101
   System.Web.Mvc.DefaultModelBinder.BindComplexElementalModel(ControllerContext controllerContext, ModelBindingContext bindingContext, Object model) +55
   System.Web.Mvc.DefaultModelBinder.BindComplexModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +1209
   System.Web.Mvc.DefaultModelBinder.BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +333
   System.Web.Mvc.ControllerActionInvoker.GetParameterValue(ControllerContext controllerContext, ParameterDescriptor parameterDescriptor) +343
   System.Web.Mvc.ControllerActionInvoker.GetParameterValues(ControllerContext controllerContext, ActionDescriptor actionDescriptor) +105
   System.Web.Mvc.Async.<>c__DisplayClass3_1.<BeginInvokeAction>b__0(AsyncCallback asyncCallback, Object asyncState) +640
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +14
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Async.AsyncControllerActionInvoker.BeginInvokeAction(ControllerContext controllerContext, String actionName, AsyncCallback callback, Object state) +346
   System.Web.Mvc.<>c.<BeginExecuteCore>b__152_0(AsyncCallback asyncCallback, Object asyncState, ExecuteCoreState innerState) +27
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +30
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Controller.BeginExecuteCore(AsyncCallback callback, Object state) +494
   System.Web.Mvc.<>c.<BeginExecute>b__151_1(AsyncCallback asyncCallback, Object callbackState, Controller controller) +16
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +20
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Controller.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +403
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +16
   System.Web.Mvc.<>c.<BeginProcessRequest>b__20_0(AsyncCallback asyncCallback, Object asyncState, ProcessRequestState innerState) +54
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +30
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) +427
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContext httpContext, AsyncCallback callback, Object state) +48
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData) +16
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +103
   System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +48
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +159

[ArgumentException:已添加具有相同密钥的项。]
系统.ThrowHelper.ThrowArgumentException（异常资源）+52
System.Collections.Generic.Dictionary`2.Insert（TKey、TValue、布尔加法）+13007142
System.Collections.Generic.CollectionExtensions.ToDictionaryFast（TValue[]数组，Func`2键选择器，IEqualityComparer`1比较器）+116
System.Web.Mvc.ModelBindingContext.get_PropertyMetadata（）+149
System.Web.Mvc.DefaultModelBinder.BindProperty（ControllerContext ControllerContext，ModelBindingContext bindingContext，PropertyDescriptor PropertyDescriptor）+176
System.Web.Mvc.DefaultModelBinder.BindProperties（ControllerContext ControllerContext，ModelBindingContext bindingContext）+101
System.Web.Mvc.DefaultModelBinder.BindCompleteXelementalModel（ControllerContext ControllerContext，ModelBindingContext bindingContext，Object model）+55
System.Web.Mvc.DefaultModelBinder.BindComplexModel（ControllerContext ControllerContext，ModelBindingContext bindingContext）+1209
System.Web.Mvc.DefaultModelBinder.BindModel（ControllerContext ControllerContext，ModelBindingContext bindingContext）+333
System.Web.Mvc.ControllerActionInvoker.GetParameterValue（ControllerContext ControllerContext，ParameterDescriptor ParameterDescriptor）+343
System.Web.Mvc.ControllerActionInvoker.GetParameterValues（ControllerContext ControllerContext，ActionDescriptor ActionDescriptor）+105
System.Web.Mvc.Async.c__显示类3_1.b__0（AsyncCallback AsyncCallback，对象asyncState）+640
System.Web.Mvc.Async.WrappedAsyncResult`1.CallBeginDelegate（AsyncCallback回调，对象callbackState）+14
System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin（异步回调，对象状态，Int32超时）+128
System.Web.Mvc.Async.AsyncControllerActionInvoker.BeginInvokeAction（ControllerContext ControllerContext，String actionName，AsyncCallback回调，对象状态）+346
System.Web.Mvc.c.b__152_0（AsyncCallback AsyncCallback，Object asyncState，ExecuteCoregreat innerState）+27
System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate（AsyncCallback回调，对象callbackState）+30
System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin（异步回调，对象状态，Int32超时）+128
System.Web.Mvc.Controller.BeginExecuteCore（异步回调，对象状态）+494
System.Web.Mvc.c.b__151_1（AsyncCallback AsyncCallback、Object callbackState、Controller）+16
System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate（AsyncCallback回调，对象callbackState）+20
System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin（异步回调，对象状态，Int32超时）+128
System.Web.Mvc.Controller.BeginExecute（RequestContext RequestContext，AsyncCallback回调，对象状态）+403
System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.BeginExecute（RequestContext RequestContext，AsyncCallback回调，对象状态）+16
System.Web.Mvc.c.b__20_0（AsyncCallback AsyncCallback，Object asyncState，ProcessRequestState innerState）+54
System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate（AsyncCallback回调，对象callbackState）+30
System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin（异步回调，对象状态，Int32超时）+128
System.Web.Mvc.MvcHandler.BeginProcessRequest（HttpContextBase httpContext，异步回调，对象状态）+427
System.Web.Mvc.MvcHandler.BeginProcessRequest（HttpContext HttpContext，异步回调，对象状态）+48
System.Web.Mvc.MvcHandler.System.Web.IHTTPassynchandler.BeginProcessRequest（HttpContext上下文，AsyncCallback cb，Object extraData）+16
System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute（）+103
System.Web.HttpApplication.executesteppl（IExecutionStep步骤）+48
System.Web.HttpApplication.ExecuteStep（IExecutionStep步骤，布尔值&同步完成）+159

---

谢谢大家!

相同的密钥意味着您正试图使用数据库中已存在的PrimaryKey保存新记录。您正在使用EntityFramework吗？或者如何保存到数据库？向我们展示您的数据库定义会很有帮助。请发布准确的错误消息，以及错误发生的方式/时间。如果可能，使用堆栈跟踪。现在还不清楚您是否存在MVC数据绑定问题或数据库问题。请将服务器端代码张贴在您试图保存的位置，您在USERACCOUNT表中定义了什么作为主键？现在很清楚您存在数据绑定问题，忘记PK和EF吧。

[ArgumentException: An item with the same key has already been added.]
   System.ThrowHelper.ThrowArgumentException(ExceptionResource resource) +52
   System.Collections.Generic.Dictionary`2.Insert(TKey key, TValue value, Boolean add) +13007142
   System.Collections.Generic.CollectionExtensions.ToDictionaryFast(TValue[] array, Func`2 keySelector, IEqualityComparer`1 comparer) +116
   System.Web.Mvc.ModelBindingContext.get_PropertyMetadata() +149
   System.Web.Mvc.DefaultModelBinder.BindProperty(ControllerContext controllerContext, ModelBindingContext bindingContext, PropertyDescriptor propertyDescriptor) +176
   System.Web.Mvc.DefaultModelBinder.BindProperties(ControllerContext controllerContext, ModelBindingContext bindingContext) +101
   System.Web.Mvc.DefaultModelBinder.BindComplexElementalModel(ControllerContext controllerContext, ModelBindingContext bindingContext, Object model) +55
   System.Web.Mvc.DefaultModelBinder.BindComplexModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +1209
   System.Web.Mvc.DefaultModelBinder.BindModel(ControllerContext controllerContext, ModelBindingContext bindingContext) +333
   System.Web.Mvc.ControllerActionInvoker.GetParameterValue(ControllerContext controllerContext, ParameterDescriptor parameterDescriptor) +343
   System.Web.Mvc.ControllerActionInvoker.GetParameterValues(ControllerContext controllerContext, ActionDescriptor actionDescriptor) +105
   System.Web.Mvc.Async.<>c__DisplayClass3_1.<BeginInvokeAction>b__0(AsyncCallback asyncCallback, Object asyncState) +640
   System.Web.Mvc.Async.WrappedAsyncResult`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +14
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Async.AsyncControllerActionInvoker.BeginInvokeAction(ControllerContext controllerContext, String actionName, AsyncCallback callback, Object state) +346
   System.Web.Mvc.<>c.<BeginExecuteCore>b__152_0(AsyncCallback asyncCallback, Object asyncState, ExecuteCoreState innerState) +27
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +30
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Controller.BeginExecuteCore(AsyncCallback callback, Object state) +494
   System.Web.Mvc.<>c.<BeginExecute>b__151_1(AsyncCallback asyncCallback, Object callbackState, Controller controller) +16
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +20
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.Controller.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +403
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.BeginExecute(RequestContext requestContext, AsyncCallback callback, Object state) +16
   System.Web.Mvc.<>c.<BeginProcessRequest>b__20_0(AsyncCallback asyncCallback, Object asyncState, ProcessRequestState innerState) +54
   System.Web.Mvc.Async.WrappedAsyncVoid`1.CallBeginDelegate(AsyncCallback callback, Object callbackState) +30
   System.Web.Mvc.Async.WrappedAsyncResultBase`1.Begin(AsyncCallback callback, Object state, Int32 timeout) +128
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContextBase httpContext, AsyncCallback callback, Object state) +427
   System.Web.Mvc.MvcHandler.BeginProcessRequest(HttpContext httpContext, AsyncCallback callback, Object state) +48
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest(HttpContext context, AsyncCallback cb, Object extraData) +16
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +103
   System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +48
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +159