c# - AssemblyResolve 未针对依赖项触发

Question

我现在正在为 AssenblyResolve 事件苦苦挣扎一段时间。我搜索了 stackoverflow 并进行了其他谷歌搜索，并尝试了所有我认为相关的内容。以下是更接近我的问题的链接(在我看来):

1. AssemblyResolve is not invoked and FileNotFoundException is thrown during serialization

2. Where to handle AssemblyResolve event in a class library?

我有一个带有静态方法的 Bootstrapper 类(为了清楚起见，我将删除我们拥有的线程安全代码:

public static void Initialize()
{
    AppDomain.CurrentDomain.AssemblyResolve += CustomResolve;
}

private static Assembly CustomResolve(object sender, ResolveEventArgs args)
{
    // There is a lot code here but basicall what it does.
    // Is determining which architecture the computer is running on and
    // extract the correct embedded dll (x86 or x64). The code was based
    // on milang on GitHub (https://github.com/milang/P4.net). And it's the same
    // purpose we want to be able to load the x86 or x64 version of the perforce dll
    // but this time with the officially Perforce supported p4api.net.
    // Once the dll is extracted we assign it to the boostrapper
    Bootstrapper._p4dnAssembly = Assembly.LoadFile(targetFileName);

    // Make sure we can satisfy the requested reference with the embedded assembly (now extracted).
    AssemblyName reference = new AssemblyName(args.Name);
    if (AssemblyName.ReferenceMatchesDefinition(reference, Bootstrapper._p4dnAssembly.GetName()))
    {
        return Bootstrapper._p4dnAssembly;
    }
}

如果我有一个带有 main 方法和静态构造函数的简单类，我就能使代码正常工作。静态构造函数只是调用 Boostrapper.Initialize() 方法。在那之后，我可以使用我的库并且它按预期工作:

public static class Test
{
    static Test()
    {
        Bootstrapper.Initialize();
    }

    public static void Main()
    {
         // Using the library here is working fine. The AssemblyResolve event was
         // fired (confirmed by a breakpoint in Visual Studio)
    }
}

我遇到的问题是是否至少存在一层依赖关系。基本上代码保持不变，但这次我的库代码在另一个库中:

public static class Test
{
    static Test()
    {
        Bootstrapper.Initialize();
    }

    public static void Main()
    {
        Class1 myClass = new Class1();

        // The following line is using the code of the extracted library, but
        // The AssemblyResolve event is not fired (or fired before I register the  
        // callback) and therefore the library is not found : result  
        // BadImageFormatException() error could not load libary because one
        myClass.Connect();
    }
}

听起来我之前提到的链接中的 #2 解释了我所看到的内容，但它不起作用。 AssemblyResove 回调上的 Visual Studio 断点永远不会被击中。

知道发生了什么事吗？

弗朗西斯

Answer 1

我知道自从提出和回答这个问题以来已经有一段时间了，但我还是想补充一下我对这个问题的看法(因为我只是在这个问题上浪费了几个小时，也许因此其他人不必)

问题基本上是这样一个事实，即应用程序试图在该方法的开头解析执行该方法所需的所有程序集:

static void main(string[] args)
{
    // <-- here the app tries to resolve MyAssembly
    // and as MyAssembly.Class1 is not found, the app crashes

    // this next line is never called:
    AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(ResolveAssembly);

    // class contained in an assemnly that we need to resolve
    MyAssembly.Class1 myClass = new MyAssembly.Class1();
}

这就是上面会崩溃的原因:ResolveAssembly 事件处理程序将永远不会被调用，因为它从未被连接。

这也是以下解决方案有效的原因(由 OP 发布):

static void main(string[] args)
{
    Initialize();
    RealMain();
}

static void Initialize()
{
    AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(ResolveAssembly);
}

static void RealMain()
{
   // <-- here the app tries to resolve MyAssembly
   // class contained in an assemnly that we need to resolve      
   MyAssembly.Class1 myClass = new MyAssembly.Class1();
   // and everything is OK
}