Azure功能,EF Core,无法加载ComponentModel.Annotations 4.2.0.0

Question

我创建了几个.Net Standard 2.0库,通过控制台应用程序测试执行,以及几个测试 - 一切都很好.

切换到azure函数,并获得以下运行时错误:

然后我尝试将该特定版本下载到API Function项目中:

我正在使用Visual Studio版本15.7.0预览5.0.我已将Azure功能更新为4.7 ...因为控制台和测试项目是 - 并且这些工作.

这是一个太多的小时..所以我希望决议不是疯狂的事情.Ef Core 2.1.0-rc1-final也在混合中.使用Required,MaxLength,NotMapped的数据注释.

图形错误说:Microsoft.EntityFrameworkCore:无法加载文件或程序集'System.ComponentModel.Annotations,Version = 4.2.0.0

Answer 1

一旦启动Azure功能,我建议在下面运行此功能.它会将任何程序集重定向到现有版本.

public class FunctionsAssemblyResolver
{
    public static void RedirectAssembly()
    {
        var list = AppDomain.CurrentDomain.GetAssemblies().OrderByDescending(a => a.FullName).Select(a => a.FullName).ToList();
        AppDomain.CurrentDomain.AssemblyResolve += CurrentDomain_AssemblyResolve;
    }

    private static Assembly CurrentDomain_AssemblyResolve(object sender, ResolveEventArgs args)
    {
        var requestedAssembly = new AssemblyName(args.Name);
        Assembly assembly = null;
        AppDomain.CurrentDomain.AssemblyResolve -= CurrentDomain_AssemblyResolve;
        try
        {
            assembly = Assembly.Load(requestedAssembly.Name);
        }
        catch (Exception ex)
        {
        }
        AppDomain.CurrentDomain.AssemblyResolve += CurrentDomain_AssemblyResolve;
        return assembly;
    }

}

Answer 2

我按照这里的说明操作:

https://codopia.wordpress.com/2017/07/21/how-to-fix-the-assembly-binding-redirect-problem-in-azure-functions/

并添加了以下重定向:

"BindingRedirects": "[ { "ShortName": "System.ComponentModel.Annotations", "RedirectToVersion": "4.2.1.0", "PublicKeyToken": "b03f5f7f11d50a3a" } ]"

注意:它不是v 4.5.0.0 ......实际上是4.2.1.0.

Answer 3

如果被误用，接受的响应将导致 CPU 泄漏+=，并且会使您的函数应用程序停止运行。如果使用 IoC，最好使用单例。这里：

public class FunctionsAssemblyResolver
{
    static FunctionsAssemblyResolver()
    {
        AppDomain.CurrentDomain.AssemblyResolve += CurrentDomain_AssemblyResolve;
    }

    // At least one static member needs to be invoked in order to execute the static constructor,
    // but it will only run the constructor once.
    public static void StaticInstance() { }

    private static Assembly CurrentDomain_AssemblyResolve(object sender, ResolveEventArgs args)
    {
        var requestedAssembly = new AssemblyName(args.Name);
        try
        {
            // Feel free to resolve any other assemblies, but this will take care of Annotations
            return requestedAssembly.Name == "System.ComponentModel.Annotations"
                ? Assembly.Load(requestedAssembly.Name)
                : null;
        }
        catch
        {
            // do nothing
        }

        return null;
    }
}

要使用，只需FunctionsAssemblyResolver.StaticInstance()在任何 IoC 解析之前调用即可。这也可以用于任何非 IoC 方法。