通过传递构造函数参数的ServiceLocator获得实例 [英] ServiceLocator get instance by passing construction parameter

问题描述

我怎样才能对象实例与服务定位器与下面的构造函数。产品code是用来初始化成员properties.For我已经在Global.asax文件中使用统一注册他们的所有其他构造函数参数构造函数的参数。

 基本方式来获得对象实例，如果构造函数参数
引用类型VAR productSettingsRepo =
      ServiceLocator.Current.GetInstance＆LT; ProductSettingsRepository＆GT;
     （）;公共ProductSettingsRepository（ILogWriter日志写进程，
        ISecurityFunctionRepository securityRepo，
        IProductSettingsManager productSettingsManager，
        IReferenceDataService referenceDataService，串
        产品code）
    {
        _logWriter =日志写;
        _securityRepo = securityRepo;
        _productSettingsManager = productSettingsManager;
        _referenceDataService = referenceDataService;
        ProductInfo = GetProductData（产品code）;
    }
 

解决方案

Service Locator模式的被认为是一种反模式，你可能要重构使用的依赖注入。

话虽如此，这里有一种方法可以解决你的问题，而无需重构：

创建一个工厂接口和类依赖于服务定位器来创建一个 ProductSettingsRepository 赋予了产品code这样的类：

 公共接口IProductSettingsRepositoryFactory
{
    ProductSettingsRepository创建（字符串产品code）;
}公共类ProductSettingsRepositoryFactory：IProductSettingsRepositoryFactory
{
    公共ProductSettingsRepository创建（字符串产品code）
    {
        返回新ProductSettingsRepository（
            ServiceLocator.Current.GetInstance＆LT; ILogWriter＆GT;（）
            ServiceLocator.Current.GetInstance＆LT; ISecurityFunctionRepository＆GT;（）
            ServiceLocator.Current.GetInstance＆LT; IProductSettingsManager＆GT;（）
            ServiceLocator.Current.GetInstance＆LT; IReferenceDataService＆GT;（）
            产品code）;
    }
}
 

然后确保你注册这个厂，像这样的统一容器：

  unity_container.RegisterType＆LT; IProductSettingsRepositoryFactory，ProductSettingsRepositoryFactory＆GT;（）;
 

然后，您可以使用它是这样的：

  VAR厂= ServiceLocator.Current.GetInstance＆LT; IProductSettingsRepositoryFactory＆GT;（）;VAR productSettingsRepo = factory.Create（我的产品code）;
 

How can i get object instance with service locator with the constructor below. ProductCode is the constructor parameter used to initialize member properties.For all other constructor parameters i have registered them using unity in global.asax file.

Basic way to get object instance if constructor parameters are 
reference type

var productSettingsRepo = 
      ServiceLocator.Current.GetInstance<ProductSettingsRepository>
     ();

public ProductSettingsRepository(ILogWriter logWriter, 
        ISecurityFunctionRepository securityRepo,
        IProductSettingsManager productSettingsManager,
        IReferenceDataService referenceDataService, string 
        productCode)
    {
        _logWriter = logWriter;
        _securityRepo = securityRepo;
        _productSettingsManager = productSettingsManager;
        _referenceDataService = referenceDataService;
        ProductInfo = GetProductData(productCode);
    }

解决方案

The Service Locator pattern is considered an anti-pattern, you might want to refactor to use Dependency Injection.

Having said that, here is one way you can fix your problem without refactoring:

Create a factory interface and class that depends on the service locator to create a ProductSettingsRepository class given the product code like this:

public interface IProductSettingsRepositoryFactory
{
    ProductSettingsRepository Create(string productCode);
}

public class ProductSettingsRepositoryFactory : IProductSettingsRepositoryFactory
{
    public ProductSettingsRepository Create(string productCode)
    {
        return new ProductSettingsRepository(
            ServiceLocator.Current.GetInstance<ILogWriter>(),
            ServiceLocator.Current.GetInstance<ISecurityFunctionRepository>(),
            ServiceLocator.Current.GetInstance<IProductSettingsManager>(),
            ServiceLocator.Current.GetInstance<IReferenceDataService>(),
            productCode);
    }
}

Then make sure that you register this factory with the unity container like this:

unity_container.RegisterType<IProductSettingsRepositoryFactory, ProductSettingsRepositoryFactory>();

Then, you can use it like this:

var factory = ServiceLocator.Current.GetInstance<IProductSettingsRepositoryFactory>();

var productSettingsRepo = factory.Create("my product code");

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