仅在访问模型时的ASP.NET Core NullReferenceException [英] ASP.NET Core NullReferenceException when just accessing model

问题描述

我在尝试使用强类型模型创建视图时遇到麻烦.无论我将模型作为什么传递给View()，即使只是访问Model，我也总是收到NullReferenceException.

I am having trouble with attempting to create a view with a strongly typed model. No matter what I pass in as the model to a View(), I always receive a NullReferenceException when even just accessing the Model.

在执行剃刀页面的其余部分之前，我什至无法检查模型是否为空；只需执行if (Model != null)也会抛出相同的NullReferenceException.

I can't even check if the model is null before executing the rest of the razor page; simply doing a if (Model != null) also throws the same NullReferenceException.

Index.cshtml

@page
@model EncodeModel
@{
    Layout = "~/Pages/Shared/_Layout.cshtml";
}

<h2>Encode</h2>

<div id="progress">
    @await Html.PartialAsync("~/Encoder/MVC/EncodeProgress.cshtml", new EncodeModule())
</div>

EncodeProgress.cshtml

@page
@model FFenc.IEncoderModule

@{
    var module = Model; //this throws the NullReferenceException
}

Startup.cs

    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        if (env.IsDevelopment())
        {
            app.UseDeveloperExceptionPage();
        }
        else
        {
            app.UseExceptionHandler("/Error");
            app.UseHsts();
        }

        app.UseHttpsRedirection();
        app.UseStaticFiles();
        app.UseCookiePolicy();

        app.UseMvc();
    }

异常堆栈跟踪:

NullReferenceException:对象引用未设置为对象的实例.

NullReferenceException: Object reference not set to an instance of an object.

AspNetCore.Encoder_MVC_EncodeProgress.get_Model()
EncodeProgress.cshtml中的AspNetCore.Encoder_MVC_EncodeProgress.ExecuteAsync()
var module = Model;

AspNetCore.Encoder_MVC_EncodeProgress.get_Model()
AspNetCore.Encoder_MVC_EncodeProgress.ExecuteAsync() in EncodeProgress.cshtml
var module = Model;

我做错了什么?我尝试了多种修复和解决方法(使用ViewComponent而不是视图)，但是没有任何效果.

What am I doing wrong? I have attempted multiple fixes and workarounds (using a ViewComponent instead of a view) but nothing works.

我发现了一些类似的问题并没有解决我的问题:

Some similar questions that I have found that have not solved my problem:

ASP.NET核心模型中的null错误索引视图

我已经传递了模型，因此此答案不会改变我所做的任何事情.例如，当我尝试使用控制器作为解决方法时，此代码也发生了相同的NullReferenceException:

I'm already passing in the model so this answer doesn't change anything about what I'm doing. For example, when I was trying to use a controller as a workaround, the same NullReferenceException happened with this code:

    [Route("/encode/progress")]
    public IActionResult GetProgress()
    {
        return View("~/Encoder/MVC/EncodeProgress.cshtml", new EncoderModule());
    }

推荐答案

我认为您正在混用

I think you're mixing Razor Pages with ASP.NET MVC. Try removing the @page directive and your model should be bound to the value passed when you call return View().

这篇关于仅在访问模型时的ASP.NET Core NullReferenceException的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！