named type not used for constructor injection
- by nmarun
Hi,
I have a simple console application where I have the following setup:
public interface ILogger
{
void Log(string message);
}
class NullLogger : ILogger
{
private readonly string version;
public NullLogger()
{
version = "1.0";
}
public NullLogger(string v)
{
version = v;
}
public void Log(string message)
{
Console.WriteLine("NULL " + version + " : " + message);
}
}
The configuration details are below:
<type type="UnityConsole.ILogger, UnityConsole" mapTo="UnityConsole.NullLogger, UnityConsole">
My calling code looks as below:
IUnityContainer container = new UnityContainer();
UnityConfigurationSection section = (UnityConfigurationSection)ConfigurationManager.GetSection("unity");
section.Containers.Default.Configure(container);
ILogger nullLogger = container.Resolve();
nullLogger.Log("hello");
This works fine, but once I give a name to this type something like:
<type type="UnityConsole.ILogger, UnityConsole" mapTo="UnityConsole.NullLogger, UnityConsole" name="NullLogger">
The above calling code does not work even if I explicitly register the type using
container.RegisterType<ILogger, NullLogger>();
I get the error:
{"Resolution of the dependency failed, type = \"UnityConsole.ILogger\", name = \"\". Exception message is: The current build operation (build key Build Key[UnityConsole.NullLogger, null]) failed: The parameter v could not be resolved when attempting to call constructor UnityConsole.NullLogger(System.String v). (Strategy type BuildPlanStrategy, index 3)"}
Why doesn't unity look into named instances? To get it to work, I'll have to do:
ILogger nullLogger = container.Resolve("NullLogger");
Where is this behavior documented?
Arun
