简单注入器:针对所选控制器的不同DbContext [英] Simple Injector: Different DbContext for selected controllers

问题描述

我正在尝试在MVC应用程序中分开读取/写入.我将Ioc用作简单注入器，并且具有以下结构:

I am trying to separate reads/writes in my MVC application. I am using Simple Injector as Ioc and I have following structure:

new Service(
  new Repository(
     new UnitOfWork(
        new DbContext())))

因此，每个网络注册的UnitOfWork请求其余的Transient.

So UnitOfWork registered per web request all the rest Transient.

因此，想法是创建单独的只读控制器，并注册DbContext，以在控制器为只读时提供不同的连接.而这可以通过 RegisterWithContext扩展但在我的情况下它将无法正常工作，因为并非所有图形节点都为Transient.

So idea was to create separate read-only controllers and make a registration of DbContext to supply a different connection if controller is read-only. And that could be achievable with improved RegisterWithContext extension BUT it will not work in my case because not all graph nodes are Transient.

有什么办法(比使用改进的RegisterWithContext扩展注册每个存储库更优雅，该地方需要提供另一个只读UnitOfWork并手动解析传递给Repository的所有其他参数)所描述的方案可以实现吗?

Is there any way (more elegant than register each Repository with improved RegisterWithContext extension where need to supply another read-only UnitOfWork and manually resolve all other arguments that passed into Repository) how the described scenario can be achieved?

推荐答案

由于选择基于控制器的类型，因此可以在自定义IControllerFactory中进行确定.例如:

Since the choice is based on the type of controller, you can make the descision in a custom IControllerFactory. For instance:

public class ConnectionSelector {
    public bool AsReadOnly { get; set; }
}

private class ReadOnlySwitchControllerFactory : DefaultControllerFactory {
    private readonly Container container;

    public ReadOnlySwitchControllerFactory(Container container) {
        this.container = container;
    }

    protected override IController GetControllerInstance(RequestContext requestContext, 
        Type controllerType) {
        var selector = this.container.GetInstance<ConnectionSelector>();

        selector.AsReadOnly = 
            typeof(IReadOnlyController).IsAssignableFrom(controllerType);

        return base.GetControllerInstance(requestContext, controllerType);
    }
}

您可以按以下步骤进行注册:

You can register this as follows:

container.RegisterPerWebRequest<ConnectionSelector>();

container.RegisterPerWebRequest<DbContext>(() => new DbContext(
    container.GetInstance<ConnectionSelector>().AsReadOnly 
        ? "ReadOnlyConnection" 
        : "NormalConnection"));

container.RegisterSingle<IControllerFactory>(
    new ReadOnlySwitchControllerFactory(container));

这篇关于简单注入器:针对所选控制器的不同DbContext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！