Question

is it possible to resolve objects which use generics in unity only using interfaces.

class

public interface ItestObject<T>{ T Create();}
public class testObject<T> : ItestObject<T> where T: class, ICMSBasicTextData, new()
{
    public testObject(){}

    public T Create()
    {
        return new T();
    }
}

xml config

<alias alias="testObject_I" type="JMJoinery.ItestObject`1, JMJoinery" />
<alias alias="testObject_C" type="JMJoinery.testObject`1[[JMJoinery.CMS.Data.CMSBasicTextData, JMJoinery]], JMJoinery" />
<alias alias="CMSBasicTextData_I" type="JMJoinery.CMS.Data.ICMSBasicTextData, JMJoinery" />
<alias alias="CMSBasicTextData_C" type="JMJoinery.CMS.Data.CMSBasicTextData, JMJoinery" />

<register name="CMSBasicTextData_R" type="CMSBasicTextData_I" mapTo="CMSBasicTextData_C" />
<register name="test" type="testObject_I" mapTo="testObject_C" />

when i try to resolve:

var o2 = JMJoinery.Global.Container.Resolve<ItestObject<ICMSBasicTextData>>();

this error occurs:

“Unable to cast object of type ‘JMJoinery.testObject1[JMJoinery.CMS.Data.CMSBasicTextData]' to type 'JMJoinery.ItestObject1[JMJoinery.CMS.Data.ICMSBasicTextData]’.”

Using

Container.Resolve<ItestObject<CMSBasicTextData>>();

works, but is it possible to resolve using the interface only

Container.Resolve<ItestObject<ICMSBasicTextData>>();

instead?

Answer 1

Interface and Implementation

public interface ILookupDataReader<T>
{

    string LookupTypeID { get; }


}


public class CountryDataReader: ILookupDataReader<ICountry>
{


    string ILookupDataReader<ICountry>.LookupTypeID
    {
        get { return Enum.GetName(typeof(LookupTypeOptions), LookupTypeOptions.Country); }
    }
}

Registration

<alias alias="ILookupDataReader" type="Co.Application.Shared.Core.BusinessObject.ILookupDataReader`1,Co.Shared.Impl"/>
<alias alias="ICountry" type="Co.Application.Shared.Core.BusinessObject.Lookup.ICountry,                             Co.Shared.Impl"/>

<register type="ILookupDataReader[ICountry]" mapTo="Co.Application.Shared.Core.BusinessObject.Lookup.CountryDataReader,Co.Shared.Impl">
      <lifetime type="singleton"/>
    </register>

Usage

[Dependency]
public ILookupDataReader<ICountry> CountryLookup { get; set; }