.NET C＃MVC项目中出现错误 [英] Error throws in .NET C# MVC project

问题描述

大家好，

当我运行下面的项目时，错误正在抛出，但如果我第二次点击相同的按钮，那么错误就不会显示。



crosoft.csharp.runtimebinder.runtimebinderexception：无法将null转换为bool，因为它是一个不可为空的值





感谢All。



我尝试过：



我尝试过在Google中出现以下错误

osoft.csharp.runtimebinder.runtimebinderexception：无法将null转换为bool，因为它是一个不可为空的值。

Hi All,
As I run the project below error is throwing but if I click the same button second time then the error is not showing.

crosoft.csharp.runtimebinder.runtimebinderexception: cannot convert null to bool because it is a non-nullable value


Thanks to All.

What I have tried:

I tried in Google with the below error
osoft.csharp.runtimebinder.runtimebinderexception: cannot convert null to bool because it is a non-nullable value.

推荐答案

错误消息非常明确：您无法将 null 值转换为 bool ，因为 bool 是一个值类型，只有引用类型（和Nullable类型，它们是一个封装的值类型）可以包含 null



为什么会这样？我们不知道 - 我们无法访问您的代码或您的数据，当然也不能运行，这就是您所需要的！



所以，这取决于你。

幸运的是，你有一个工具可以帮助你找到正在发生的事情：调试器。你如何使用它取决于你的编译器系统，但是一个快速的谷歌用于你的IDE名称和调试器应该给你你需要的信息。



放一个断点在函数的第一行，并通过调试器运行代码。然后查看您的代码，并查看您的数据并找出手动应该发生的事情。然后单步执行每一行检查您预期发生的情况正是如此。如果不是，那就是当你遇到问题时，你可以回溯（或者再次运行并仔细观察）以找出原因。


对不起，但我们不能为你做到这一点 - 时间让你学习一门新的（非常非常有用的）技能：调试！

The error message is pretty explicit: you cannot convert a null value to a bool because bool is a Value Type, and only Reference Types (and Nullable types, which are an encapsulated Value Type) can contain a null

Why is it happening? We have no idea - we don't have access to your code, or your data, and certainly not while it is running, which is what you need!

So, it's going to be up to you.
Fortunately, you have a tool available to you which will help you find out what is going on: the debugger. How you use it depends on your compiler system, but a quick Google for the name of your IDE and "debugger" should give you the info you need.

Put a breakpoint on the first line in the function, and run your code through the debugger. Then look at your code, and at your data and work out what should happen manually. Then single step each line checking that what you expected to happen is exactly what did. When it isn't, that's when you have a problem, and you can back-track (or run it again and look more closely) to find out why.

Sorry, but we can't do that for you - time for you to learn a new (and very, very useful) skill: debugging!

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