调用 Assembly.Load(byte[]) 可以引发 AppDomain.AssemblyResolve 事件吗? [英] Can a call to Assembly.Load(byte[]) raise the AppDomain.AssemblyResolve event?

问题描述

假设我有一个 AppDomain.AssemblyResolve<的处理程序/a> 事件，并在处理程序中构造一个字节数组并调用方法 Assembly.Load(字节[]).此方法本身是否会导致 AssemblyResolve 事件再次引发，并导致我的处理程序重新进入?

Suppose I have a handler for AppDomain.AssemblyResolve event, and in the handler I construct a byte array and invoke the method Assembly.Load(byte[]). Can this method itself cause the AssemblyResolve event to be raised again, and cause my handler to be re-entered?

我的问题不仅限于可以使用 C# 编译器生成的程序集，它们还可以包含 CLR 支持的 abritrary 元数据和可执行代码.

My question is not restricted only to assemblies that can be generated using C# compiler, they can contain abritrary metadata and executable code supported by the CLR.

我做了一些实验，没有发现任何发生的情况.我尝试加载需要额外引用的程序集，尝试将 CAS 属性添加到加载的程序集，其解码需要另一个程序集，尝试使用模块初始值设定项(全局 .cctor 方法)加载程序集.在任何情况下，我都没有观察到从 Assembly.Load(byte[]) 方法内部引发的 AssemblyResolve 事件，只有在某些代码稍后尝试访问类型时才会发生，加载的程序集中的方法或属性.但我可能在这里遗漏了一些东西.

I did some experiments and haven't find any cases when it happens. I tried to load assemblies that require additional references, tried to add CAS attributes to the loaded assembly whose decoding would require another assembly, tried to load an assembly with a module initializer (global .cctor method). In no case I observed the AssemblyResolve event to be raised from inside the Assembly.Load(byte[]) method, it only happened if some code later tried to access types, methods or attributes in the loaded assembly. But I can be missing something here.

推荐答案

据我所知 Assembly.Load 或通过其他方式加载程序集不会执行任何可由 C# 编译器生成的构造函数(包括静态构造函数).因此，您不会在常见的程序集上重新进入 AssemblyResolve.

To my knowledge Assembly.Load or loading assembly by other means does not execute any constructors that can be generated by the C# compiler (including static constructors). As result you're not going to get reentrancy to AssemblyResolve on commonly found assemblies.

正如您在问题中提到的，在 Load 调用期间不会执行模块初始值设定项.包含在 CLI 规范中的保证列表中 - 摘录可以在 Module Initializers 作者:Junfeng Zhang.

As you've mentioned in the question, module initializers are not executed during the Load call. Covered in list of guarantees in CLI spec - excerpt can be found in Module Initializers by Junfeng Zhang.

B.模块的初始化方法在第一次访问模块中定义的任何类型、方法或数据时或之前的某个时间执行

B. The module’s initializer method is executed at, or sometime before, first access to any types, methods, or data defined in the module

有相关的 SO 问题通常讨论在任何类型构造函数之前运行代码"，例如 初始化库装配负荷.请注意，.Net:加载程序集时运行代码 Marc Gravell 的回答指出，由于安全限制，这可能是不可能的.

There are related SO questions usually discussing "run code before any type constructors" like Initialize library on Assembly load. Note that .Net: Running code when assembly is loaded has an answer by Marc Gravell that states it may not be possible due to security constraints.

这篇关于调用 Assembly.Load(byte[]) 可以引发 AppDomain.AssemblyResolve 事件吗?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！