我在Firebase中递增数据时遇到问题。Firebase{clickedCounter:0}这是我的代码:@IBActionfuncplus(sender:UIButton){FIRDatabase.database().reference().child("clickedCounter").observeEventType(.Value){(snap:FIRDataSnapshot)inletvalue=FIRDatabase.database().reference().child("clickedCounter")as?NSNumberletincrement=((value?