c# - 非静态方法需要一个目标

Question

我有一个 Controller 操作，在本地和生产环境中都可以在 Firefox 和 IE 上正常工作，但在生产环境中不能正常工作。这是我的 Controller 操作:

public ActionResult MNPurchase()
{
    CalculationViewModel calculationViewModel = (CalculationViewModel)TempData["calculationViewModel"];

    decimal OP = landTitleUnitOfWork.Sales.Find()
        .Where(x => x.Min >= calculationViewModel.SalesPrice)
        .FirstOrDefault()
        .OP;

    decimal MP = landTitleUnitOfWork.Sales.Find()
        .Where(x => x.Min >= calculationViewModel.MortgageAmount)
        .FirstOrDefault()
        .MP;

    calculationViewModel.LoanAmount = (OP + 100) - MP;
    calculationViewModel.LendersTitleInsurance = (calculationViewModel.LoanAmount + 850);

    return View(calculationViewModel);
}

这是我在 IE 中得到的堆栈跟踪:

Error. An error occurred while processing your request. System.Reflection.TargetException: Non-static method requires a target. at System.Reflection.RuntimeMethodInfo.CheckConsistency(Object target) at System.Reflection.RuntimeMethodInfo.InvokeArgumentsCheck(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture) at System.Reflection.RuntimePropertyInfo.GetValue(Object obj, Object[] index) at System.Data.Objects.ELinq.QueryParameterExpression.TryGetFieldOrPropertyValue(MemberExpression me, Object instance, Object& memberValue) at System.Data.Objects.ELinq.QueryParameterExpression.TryEvaluatePath(Expression expression, ConstantExpression& constantExpression) at System.Data.Objects.ELinq.QueryParameterExpression.EvaluateParameter(Object[] arguments) at System.Data.Objects.ELinq.ELinqQueryState.GetExecutionPlan(Nullable1 forMergeOption)
at System.Data.Objects.ObjectQuery1.GetResults(Nullable1 forMergeOption) at
System.Data.Objects.ObjectQuery1.System.Collections.Generic.IEnumerable.GetEnumerator() at System.Linq.Enumerable.FirstOrDefault[TSource](IEnumerable1 source) at
System.Linq.Queryable.FirstOrDefault[TSource](IQueryable1 source) at LandTitle.Controllers.HomeController.MNRefi() at lambda_method(Closure , ControllerBase , Object[] ) at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary2 parameters) at
System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext
controllerContext, ActionDescriptor actionDescriptor, IDictionary2 parameters) at Castle.Proxies.Invocations.ControllerActionInvoker_InvokeActionMethod.InvokeMethodOnTarget() at Castle.DynamicProxy.AbstractInvocation.Proceed() at Glimpse.Mvc3.Interceptor.InvokeActionMethodInterceptor.Intercept(IInvocation invocation) at Castle.DynamicProxy.AbstractInvocation.Proceed() at Castle.Proxies.AsyncControllerActionInvokerProxy.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary``2 parameters) at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass37.<>c__DisplayClass39.b__33() at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass4f.b__49() at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass37.b__36(IAsyncResult asyncResult) at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass25.<>c__DisplayClass2a.b__20() at System.Web.Mvc.Async.AsyncControllerActionInvoker.<>c__DisplayClass25.b__22(IAsyncResult asyncResult)

Answer 1

我认为当您在 lambda 中使用在运行时为空引用的变量时，会发生这种令人困惑的异常。在您的情况下，我会检查您的变量 calculationViewModel 是否为空引用。

类似于:

public ActionResult MNPurchase()
{
    CalculationViewModel calculationViewModel = (CalculationViewModel)TempData["calculationViewModel"];

    if (calculationViewModel != null)
    {
        decimal OP = landTitleUnitOfWork.Sales.Find()
            .Where(x => x.Min >= calculationViewModel.SalesPrice)
            .FirstOrDefault()
            .OP;

        decimal MP = landTitleUnitOfWork.Sales.Find()
            .Where(x => x.Min >= calculationViewModel.MortgageAmount)
            .FirstOrDefault()
            .MP;

        calculationViewModel.LoanAmount = (OP + 100) - MP;
        calculationViewModel.LendersTitleInsurance = (calculationViewModel.LoanAmount + 850);

        return View(calculationViewModel);
    }
    else
    {
        // Do something else...
    }
}