She turned the matter over in her mind for a long while, but still could not come to a decision.

她忖量了半天，还拿不定主意。

《新英汉大辞典》

You're going to blow me to a good lunch. It's the last square meal you're going to have over here - maybe for a long while.

你得请我吃一顿好饭，这是你在这儿吃的最后一顿丰盛的饭了，也许过很久才能再吃到呢。

youdao

At her mother's proposal, the girl thought for a long while. All of a sudden, she went to the neighbor and knocked at the door.

女孩听到妈妈的提议，认真的思考了很久，突然走到邻居家敲响了门。

youdao

"There may be enough to eat for a while." he says, "but before too long there may be hunger."

VOA: special.2010.04.13

Yes-- for a while, but not for long.

是的，更快乐一段时间并不长久。

哈佛公开课 - 幸福课课程节选

"It will for a long time, at least while I am alive. And it is not just trucks and heavy machinery.

VOA: standard.2009.09.02

In front of the mirror she stared at herself thoughtfully for a long while.

NEWYORKER: Miracle Polish

For a long while it was about struggling to survive, struggling to get better.

WSJ: Designer Rick Owens's Paris Home | WSJ. Magazine May 2013

That moment is unlikely to result from a bold diplomatic initiative for a long while.

ECONOMIST: War and diplomacy in Syria