"that's done it" in Chinese (Simplified)
完了这下好了（表示后果）
Definition
用来表示由于某个行为，刚刚发生了重要或麻烦的事。通常意味着你已经造成了某种效果，往往是负面的或不可逆的。
Usage Notes (Chinese (Simplified))
非正式表达。多用于出了问题或某个动作导致不可逆转的事情时。有时带有幽默或无奈的语气。常见于意外和失误后，不用于正式场合。
Examples
Oh no, I dropped the cake. That's done it.
糟了，蛋糕掉地上了。**完了**。
You unplugged the computer before saving. That's done it.
你还没保存就拔掉了电脑电源。**这下好了**。
The car won't start? That's done it for our trip.
车发动不了？**完了**，我们的旅行没戏了。
Well, that's done it—there's no way to fix the broken screen now.
唉，**完了**——这下屏幕没法修了。
Great, you spilled coffee on the report. That's done it!
好嘛，你把咖啡洒在报告上。**这下好了**！
If you weren't already in trouble, that's done it!
如果你之前还没麻烦，**这下肯定完了**！