“Well, I certainly did have a drink...and I came back...after a fashion, ” mumbled Dumbledore. “So you decided to spring a trap for me? ”

“是啊，我确实是去喝了些东西… … 现在我回来了… … 勉强回来了，”邓布利多轻声嘟囔道，“所以你就决定给我设置一个陷阱？”

" To spring for (something)" means to pay for something; it's an informal way of saying to buy or to pay for – " to spring for (something)" .

“to spring for (something)”表示为某事付出；这是购买或支付的一种非正式说法 – “为（某物）而努力”。

I tried to observe him closely while he was resting in the intervals of his performances; but he would not allow a near approach, always getting his jumping legs ready to spring for immediate flight, and keeping his eyes on me.

当他在表演的间隙休息时，我试图仔细观察他。但他不允许靠近，总是让他跳跃的腿准备好立即起飞，并注视着我。