我有一个使用淡入淡出动画的div。完成后，我相信它会设置library(data.table)
#Create the fictional data up to the current choice.
choices<-c(1:100) #vector of possible choices
people<-data.frame(ID=1:10)
setDT(people,key="ID")
people[,current_choice:=sample(choices,1),by= .(ID)] #what the person uses now
people[,chosen := sample(choices,1),by= .(ID)] #what the person actually picked at t_2
#expand the dataset to be 30 rows per person and create a choice ID
people<-people[rep(1:.N,30),]
setDT(people,key="ID")
people[,choice_id:=seq_len(.N), by=.(ID)]
#The current choice at t_1 needs to be in the choice set
## the `choice_id == 1L` is critical here, filtering by just `people[1, ...]` wasn't giving
## the result you were actually going for
people[choice_id == 1L, choice_set := current_choice, by=.(ID)]
#The actual choice needs to be in the choice set
people[choice_id == 2L
& current_choice != chosen, choice_set := chosen, by= .(ID)]
## Use setdiff to make sure we sample the rest from a vector excluding the
## `current_choice` and `chosen` values
people[choice_id > 2L, choice_set := sample(setdiff(choices,c(current_choice,chosen)), .N), by = .(ID)]
，此时它下面的内容会跳起来填充该空间。如何使它更平滑？我以为也许在动画结尾时，我可以插入高度完全相同的display:none div，并为其高度缩小设置动画。但这感觉很普通，我不想在这里重新发明轮子。
答案 0 :(得分：1)
display: none将从DOM中完全删除该元素，并且自然而然地其余元素将“跳起来”以取代它的位置...如果您不希望这样做，可以简单地将其设置为{{ 1}}或visibility: hidden ...，而不是使用相同的...创建占位符div ...