无法在 razor 中创建编辑器，需要 System.Windows.Forms答案

【问题标题】：Cannot create an editor in razor, System.Windows.Forms is needed无法在 razor 中创建编辑器，需要 System.Windows.Forms
【发布时间】：2021-01-27 12:53:43
【问题描述】：

我在 ASP.NET 中有这个非常基本的表单：

@using (Html.BeginForm("Edit", "Home", FormMethod.Post))
{
    @Html.ValidationSummary(true)
    <fieldset>
        @Html.EditorFor(item => item.Name)
        <input type="submit" value="Upload" />
    </fieldset>
}

当我删除@Html.EditorFor(item => item.Name) 行时，一切正常。但是当我添加它时，我收到以下错误：

FileNotFoundException: 无法加载文件或程序集 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'。

为什么在 ASP 中需要 Windows 窗体？？？有没有其他人遇到过同样的问题？我在 Rider 中使用 MVC 创建了一个普通的 WebApplication。目标框架为netcoreapp3.1，语言版本为C# 8.0。如果您需要更多详细信息，请随时询问。

错误的整个调用栈如下：

System.IO.FileNotFoundException: Could not load file or assembly 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'. File not found.
File name: 'System.Windows.Forms, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089'
   at System.Reflection.CustomAttribute._CreateCaObject(RuntimeModule pModule, RuntimeType type, IRuntimeMethodInfo pCtor, Byte** ppBlob, Byte* pEndBlob, Int32* pcNamedArgs)
   at System.Reflection.CustomAttribute.CreateCaObject(RuntimeModule module, RuntimeType type, IRuntimeMethodInfo ctor, IntPtr& blob, IntPtr blobEnd, Int32& namedArgs)
   at System.Reflection.CustomAttribute.AddCustomAttributes(ListBuilder`1& attributes, RuntimeModule decoratedModule, Int32 decoratedMetadataToken, RuntimeType attributeFilterType, Boolean mustBeInheritable, ListBuilder`1 derivedAttributes)
   at System.Reflection.CustomAttribute.GetCustomAttributes(RuntimeModule decoratedModule, Int32 decoratedMetadataToken, Int32 pcaCount, RuntimeType attributeFilterType)
   at System.Reflection.RuntimePropertyInfo.GetCustomAttributes(Type attributeType, Boolean inherit)
   at System.Attribute.InternalGetCustomAttributes(PropertyInfo element, Type type, Boolean inherit)
   at System.Attribute.GetCustomAttributes(MemberInfo element, Boolean inherit)
   at System.Reflection.CustomAttributeExtensions.GetCustomAttributes(MemberInfo element)
   at Microsoft.AspNetCore.Mvc.ModelBinding.ModelAttributes.GetAttributesForProperty(Type containerType, PropertyInfo property, Type modelType)
   at Microsoft.AspNetCore.Mvc.ModelBinding.Metadata.DefaultModelMetadataProvider.CreateSinglePropertyDetails(ModelMetadataIdentity propertyKey, PropertyHelper propertyHelper)
   at Microsoft.AspNetCore.Mvc.ModelBinding.Metadata.DefaultModelMetadataProvider.CreatePropertyDetails(ModelMetadataIdentity key)
   at Microsoft.AspNetCore.Mvc.ModelBinding.Metadata.DefaultModelMetadataProvider.GetMetadataForProperties(Type modelType)
   at Microsoft.AspNetCore.Mvc.ModelBinding.Metadata.DefaultModelMetadata.get_Properties()
   at Microsoft.AspNetCore.Mvc.ViewFeatures.ExpressionMetadataProvider.FromLambdaExpression[TModel,TResult](Expression`1 expression, ViewDataDictionary`1 viewData, IModelMetadataProvider metadataProvider)
   at Microsoft.AspNetCore.Mvc.ViewFeatures.ModelExpressionProvider.CreateModelExpression[TModel,TValue](ViewDataDictionary`1 viewData, Expression`1 expression)
   at Microsoft.AspNetCore.Mvc.ViewFeatures.HtmlHelper`1.GetModelExpression[TResult](Expression`1 expression)
   at Microsoft.AspNetCore.Mvc.ViewFeatures.HtmlHelper`1.EditorFor[TResult](Expression`1 expression, String templateName, String htmlFieldName, Object additionalViewData)
   at Microsoft.AspNetCore.Mvc.Rendering.HtmlHelperEditorExtensions.EditorFor[TModel,TResult](IHtmlHelper`1 htmlHelper, Expression`1 expression)
   at AspNetCore.Views_Home_Edit.ExecuteAsync() in /my/path/Edit.cshtml:line 16
   at Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderPageCoreAsync(IRazorPage page, ViewContext context)
   at Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderPageAsync(IRazorPage page, ViewContext context, Boolean invokeViewStarts)
   at Microsoft.AspNetCore.Mvc.Razor.RazorView.RenderAsync(ViewContext context)
   at Microsoft.AspNetCore.Mvc.ViewFeatures.ViewExecutor.ExecuteAsync(ViewContext viewContext, String contentType, Nullable`1 statusCode)
   at Microsoft.AspNetCore.Mvc.ViewFeatures.ViewExecutor.ExecuteAsync(ViewContext viewContext, String contentType, Nullable`1 statusCode)
   at Microsoft.AspNetCore.Mvc.ViewFeatures.ViewExecutor.ExecuteAsync(ActionContext actionContext, IView view, ViewDataDictionary viewData, ITempDataDictionary tempData, String contentType, Nullable`1 statusCode)
   at Microsoft.AspNetCore.Mvc.ViewFeatures.ViewResultExecutor.ExecuteAsync(ActionContext context, ViewResult result)
   at Microsoft.AspNetCore.Mvc.ViewResult.ExecuteResultAsync(ActionContext context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResultFilterAsync>g__Awaited|29_0[TFilter,TFilterAsync](ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResultExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.ResultNext[TFilter,TFilterAsync](State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeResultFilters()
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted)
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.InvokeFilterPipelineAsync()
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Awaited|17_0(ResourceInvoker invoker, Task task, IDisposable scope)
   at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger)
   at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context)

【问题讨论】：

那个异常的调用栈是什么？它可以解释你需要的一切。
我添加了它的调用栈。我认为它说我以错误的方式调用了 EditorFor...

标签： c# razor-pages rider

【解决方案1】：

我找到了问题！我从另一个项目的文件中导入了一个枚举，其中也导入了System.Windows.Forms。将枚举移到其他地方解决了这个问题。现在我只导入不导入 System.Windows.Forms 的东西。

如果您碰巧遇到同样的问题：检查您的导入，以及您的导入的导入。

【讨论】：