Question

How can I make Unity not to throw ResolutionFailedException if Resolve fails?

Is there something like TryResolve<IMyInterface>?

var container = new UnityContainer();
var foo = container.TryResolve<IFoo>();
Assert.IsNull(foo);

Answer 1

This has been an issue on the codeplex site, you can find the code here (look at the bottom of that thread and they have made an extension method…very handy)

http://unity.codeplex.com/Thread/View.aspx?ThreadId=24543

and the you can use code like this:

if (container.CanResolve<T>() == true)
{
    try
    {
        return container.Resolve<T>();
    }
    catch (Exception e)
    {
        // do something else
    }
}

CanResolve is that extension method. I’m actually registering that extension upon creation of the container…something like this:

private void CreateContainer()
{
    ExeConfigurationFileMap map = new ExeConfigurationFileMap();

    map.ExeConfigFilename = // path to config file

    // get section from config code goes here

    IUnityContainer container = new UnityContainer();
    container.AddNewExtension<UnityExtensionWithTypeTracking>();
    section.Containers.Default.Configure(container);        
}