我有一个类型在其构造函数中接收另一个类型,通常是创建它的对象的类型,例如:
public class Logger {
public Logger(Type parent) { ... }
}
我想指示 Unity 解析 Logger
将需要它的对象的类型作为参数传递给其构造函数。像这样的东西:
// ... would be some directive to tell Unity to use the type that
/// depends on Logger
container.RegisterType<Logger>(new InjectionConstructor(...));
所以当我尝试解析 MyService
时:
public MyService {
public MyService(Logger logger) { ... }
}
它将返回:
var logger = new Logger(typeof(MyService));
return new MyService(logger);
这可能吗?还有其他方法吗?
最佳答案
实际上,你可以这样做:
internal class Program
{
static void Main( string[] args )
{
var container = new UnityContainer();
container.RegisterType<IInterface, Implementation>( new MyInjectionConstructor() );
// this instance will get a logger constructed with loggedType == typeof( Implementation )
var instance = container.Resolve<IInterface>();
}
}
internal class MyInjectionConstructor : InjectionMember
{
public override void AddPolicies( Type serviceType, Type implementationType, string name, IPolicyList policies )
{
policies.Set<IConstructorSelectorPolicy>( new MyConstructorSelectorPolicy(), new NamedTypeBuildKey( implementationType, name ) );
}
}
internal class MyConstructorSelectorPolicy : DefaultUnityConstructorSelectorPolicy
{
protected override IDependencyResolverPolicy CreateResolver( ParameterInfo parameter )
{
if( parameter.ParameterType == typeof( ILogger ) )
{
return new LiteralValueDependencyResolverPolicy( new Logger( parameter.Member.DeclaringType ) );
}
return base.CreateResolver( parameter );
}
}
internal interface ILogger
{
}
internal class Logger : ILogger
{
public Logger( Type loggedType )
{
}
}
internal interface IInterface
{
}
internal class Implementation : IInterface
{
public Implementation( ILogger logger )
{
}
}
这只是概念代码的证明,在生产使用之前可能需要稍微改进一下......
关于c# - 如何获取在 Unity 中注入(inject)的对象的类型?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/43056082/