具有ValidationAttribute的Autofac属性注入 [英] Autofac property injection with ValidationAttribute

问题描述

我有一个ValidationAttribute，看起来像这样:

public class RegistrationUniqueNameAttribute : ValidationAttribute
{
    public IRepository<User> UserRepository { get; set; }

    public override bool IsValid(object value)
    {
       //use UserRepository here....
    }
}

在我的容器设置中(在应用启动时)，我有以下内容:

        builder.Register(c => new RegistrationUniqueEmailAttribute
            {
                UserRepository = c.Resolve<IRepository<User>>()
            });

但是，在调试时，UserRepository的值始终为null，因此不会注入该属性.

我的容器设置错误吗?

我真的宁愿不必使用DependencyResolver.Current.GetService<IRepository<User>>()，因为这不是可测试的...

解决方案

不，Autofac v3对ValidationAttribute并没有做任何特别的事情，朋友[[c2>做很多强大的事情，例如，使用过滤器属性]./p>

在此答案中，我间接解决了问题，使一个人可以编写:

class MyModel 
{
    ...
    [Required, StringLength(42)]
    [ValidatorService(typeof(MyDiDependentValidator), ErrorMessage = "It's simply unacceptable")]
    public string MyProperty { get; set; }
    ....
}

public class MyDiDependentValidator : Validator<MyModel>
{
    readonly IUnitOfWork _iLoveWrappingStuff;

    public MyDiDependentValidator(IUnitOfWork iLoveWrappingStuff)
    {
        _iLoveWrappingStuff = iLoveWrappingStuff;
    }

    protected override bool IsValid(MyModel instance, object value)
    {
        var attempted = (string)value;
        return _iLoveWrappingStuff.SaysCanHazCheez(instance, attempted);
    }
}

(以及一些帮助程序类，它们连接到ASP.NET MVC ...)

I've got a ValidationAttribute that looks like this:

public class RegistrationUniqueNameAttribute : ValidationAttribute
{
    public IRepository<User> UserRepository { get; set; }

    public override bool IsValid(object value)
    {
       //use UserRepository here....
    }
}

In my container setup (in app start) I have this:

        builder.Register(c => new RegistrationUniqueEmailAttribute
            {
                UserRepository = c.Resolve<IRepository<User>>()
            });

However, when debugging, the value of UserRepository is always null, so the property isn't getting injected.

Have I set up my container wrong?

I'd really rather not have to use DependencyResolver.Current.GetService<IRepository<User>>() as this isn't as testable...

解决方案

No, Autofac v3 doesn't do anything special with ValidationAttribute and friends [Autofac.Mvc does lots of powerful things e.g., with filter attributes].

I solved the problem indirectly in this answer, enabling one to write:

class MyModel 
{
    ...
    [Required, StringLength(42)]
    [ValidatorService(typeof(MyDiDependentValidator), ErrorMessage = "It's simply unacceptable")]
    public string MyProperty { get; set; }
    ....
}

public class MyDiDependentValidator : Validator<MyModel>
{
    readonly IUnitOfWork _iLoveWrappingStuff;

    public MyDiDependentValidator(IUnitOfWork iLoveWrappingStuff)
    {
        _iLoveWrappingStuff = iLoveWrappingStuff;
    }

    protected override bool IsValid(MyModel instance, object value)
    {
        var attempted = (string)value;
        return _iLoveWrappingStuff.SaysCanHazCheez(instance, attempted);
    }
}

(And some helper classes inc wiring to ASP.NET MVC...)

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