AppDomain.CurrentDomain.AssemblyResolve in dynamics crm

Question

因此,我在很多文章中引用了AppDomain.CurrentDomain.AssemblyResolve在运行时将嵌入式资源中的DLL加载到插件中的用法(不使用IlMerge).但是,当我插入此代码时,事件处理程序永远不会在插件为我的主库抛出TypeLoadException消息之前接收该线程.

我已经尝试将代码放在静态构造函数中,在Execute方法内部和主构造函数中; 虽然事件处理程序已注册,但处理程序中的断点不会被命中.

环境是Dynamics CRM 2011,最新汇总并使用SDK开发人员工具插件项目和插件类生成.

任何人都知道我需要做些什么才能让它发挥作用？

Answer 1

在您通过该回调加载计划的程序集中引用任何类型之前,发生AssemblyResolve事件注册非常重要.即使您没有在静态构造函数中引用类型,也必须确保类中没有静态变量,或者它是引用外部程序集中类型的基类.

我是这样做的:我有一个单独的类来处理程序集加载,恰当地命名为AssemblyLoader:

using System;
using System.IO;
using System.Linq;
using System.Reflection;

internal static class AssemblyLoader
{
    internal static void RegisterAssemblyLoader()
    {
        AppDomain currentDomain = AppDomain.CurrentDomain;
        currentDomain.AssemblyResolve -= OnResolveAssembly;
        currentDomain.AssemblyResolve += OnResolveAssembly;
    }

    private static Assembly OnResolveAssembly(object sender, ResolveEventArgs args)
    {
        return LoadAssemblyFromManifest(args.Name);
    }

    private static Assembly LoadAssemblyFromManifest(string targetAssemblyName)
    {
        Assembly executingAssembly = Assembly.GetExecutingAssembly();
        AssemblyName assemblyName = new AssemblyName(targetAssemblyName);

        string resourceName = DetermineEmbeddedResourceName(assemblyName, executingAssembly);

        using (Stream stream = executingAssembly.GetManifestResourceStream(resourceName))
        {
            if (stream == null)
                return null;

            byte[] assemblyRawBytes = new byte[stream.Length];
            stream.Read(assemblyRawBytes, 0, assemblyRawBytes.Length);


            return Assembly.Load(assemblyRawBytes);
        }

    }

    private static string DetermineEmbeddedResourceName(AssemblyName assemblyName, Assembly executingAssembly)
    {
        //This assumes you have the assemblies in a folder named "EmbeddedAssemblies"
        string resourceName = string.Format("{0}.EmbeddedAssemblies.{1}.dll",
                                            executingAssembly.GetName().Name, assemblyName.Name);

        //This logic finds the assembly manifest name even if it's not an case match for the requested assembly                          
        var matchingResource = executingAssembly.GetManifestResourceNames()
                                                .FirstOrDefault(res => res.ToLower() == resourceName.ToLower());

        if (matchingResource != null)
        {
            resourceName = matchingResource;
        }
        return resourceName;
    }
}

然后,在我的插件类中,我使用静态构造函数调用我的AssemblyLoader.通过将逻辑移动到单独的类中,我限制了我在插件类的静态上下文中引用的类型的数量,从而降低了我不小心引用外部程序集中的内容的风险.

using System;
using Microsoft.Xrm.Sdk;

public class MyPlugin : IPlugin
{
    static MyPlugin()
    {
        AssemblyLoader.RegisterAssemblyLoader();
    }

    public void Execute(IServiceProvider serviceProvider)
    {
        //...
    }
}

我还将外部程序集的所有用法移动到其他类中,以便我的插件类根本不使用它.大多数情况下,这是非常谨慎的.