Question

I have the following Service class constructor:

public class Service : IService
{
    private readonly IRepository _repository;

    public Service(IRepository repository)
    {
        _repository = repository;
    }

    // ...
}

IRepository has two named implementations. I want to Resolve IService but need to set which IRepository implementation should be used (Service should be flexible and I can’t put Dependency attribute to IRepository constructor parameter).

Is there any way to implement it by Unity?

Answer 1

You can use the unity config section to achieve this.
Check this link.

In the config section you can specify the mapping as follows.

 <type type="IMyService" mapTo="MyDataService" name="DataService">
      <typeConfig extensionType="Microsoft.Practices.Unity.Configuration.TypeInjectionElement,
                                 Microsoft.Practices.Unity.Configuration">
        <constructor>
          <param name="connectionString" parameterType="string">
            <value value="AdventureWorks"/>
          </param>
          <param name="logger" parameterType="ILogger">
            <dependency />
          </param>
        </constructor> 
        <property name="Logger" propertyType="ILogger" />
        <method name="Initialize">
          <param name="connectionString" parameterType="string">
            <value value="contoso"/>
          </param>
          <param name="dataService" parameterType="IMyService">
            <dependency />
          </param>
        </method>
      </typeConfig>
    </type>