为什么Unity的RegisterInstance <...>会导致Unity返回多个实例？

您已使用IValidator配置容器,因此您必须使用IValidator而不是Validator来解决:

Validator validator1 = new Validator(); 
IUnityContainer container = new UnityContainer(); 
container.RegisterInstance(validator1); 
Validator validatorCopied = validator1; 
Console.WriteLine(validator1.GetHashCode());
Console.WriteLine(validatorCopied.GetHashCode());
IValidator validator2 = container.Resolve();            
Console.WriteLine(validator2.GetHashCode());             
IValidator validator3 = container.Resolve();            
Console.WriteLine(validator3.GetHashCode()); 

或者,您可以使用Validator保持注册,但之后您还必须使用Validator解决:

Validator validator1 = new Validator();
IUnityContainer container = new UnityContainer();
container.RegisterInstance(validator1);
Validator validatorCopied = validator1;
Console.WriteLine(validator1.GetHashCode());
Console.WriteLine(validatorCopied.GetHashCode());
Validator validator2 = container.Resolve();
Console.WriteLine(validator2.GetHashCode());
Validator validator3 = container.Resolve();
Console.WriteLine(validator3.GetHashCode());