This is my view and how I deal with various situations.
First, I do not offer up the fact that I am widowed unless I feel it is important to share that fact with the person I am having the conversation with, and the details are germane to that conversation.
Otherwise, if somehow the fact that I am a widower comes up, and then asked how did she die, I usually respond with "Does it really matter?" or if I feel like being more polite, a simple "How she died is not important." Then I move on to other topics of conversation.
For awhile I was the one who offered up the fact that my wife died, and then went on to share the details. Eventually it became clear to me that I had the need to tell the story, not the person to whom I was sharing this history, to hear it. Now when I feel compelled to relate what happened, I go back to the drop in grief group, where the story can be told once again, and then interacting with others, I try to find the reason I am so compelled to tell it yet once more.
If someone who is not close to me sees me sad or depressed, and out of concern asks me what is bothering me, I usually just say "Personal stuff, it will pass."
What I have found after nine months is that in the vast majority of encounters with new friends or strangers, the topic of the death of a loved one never comes up unless I offer it up. Which as I have said, is rarely now done, and when done, I am selective in who I share this part of me with. The truth I have learned is the issue of the death of my wife, my feelings, and other aspects of grief are more a problem for me, then for the person I am talking with. Most people accept the briefest of explanations. And those who don't, well are they really worth talking to about such an intimate matter?
Just my two cents worth.
Oh, one last thing. I always bring up the fact that I am a widower with women I have an interest in establishing a relationship. Some will bolt when they hear I have only nine months into this new world of mine. Those who remain, often have to be reminded of my less frequent moments of grief and they ask "What is wrong". Surprising to me is their understanding response of, "Oh, I forgot you were widowed and still have grief issues." For me, this is a good sign, it tells me I am once again who I was, and the loss of my wife no longer controls my destiny.