DI - Constructor injection / Setter Injection ?

[kri shan]

What criteria we choose constructor injection or setter injection ?

[Jeanne Boyarsky]

Constructor injection is good when you want to force the caller to pass something and not default.

In practice, I tend to use a mix of the two. I use setter injection mainly when:
- Injecting more than one thing
- I don't control the constructor
- I'm only injecting for testing and the "real code" doesn't need to inject.

[Hong Anderson]

Setter injection allows re-injecting. Constructor injection makes sure the client will get fully-configured object.
I prefer setter injection.

[Dhanji Prasanna]

I spend several chapters on this subject =)

But the short of it is: prefer Constructor DI almost always, except when you have a circular reference to resolve.

[Hong Anderson]

Dhanji Prasanna wrote:
But the short of it is: prefer Constructor DI almost always, except when you have a circular reference to resolve.

Could you please to give a short explanation why you prefer constructor DI?
Thanks.