使用Less循环优化CSS？

Question

我正在尝试强制应用级联样式效果，通过在每个迭代中延迟动画几秒钟来实现：

.stashCard {
    background-color:white;
}

.in(@delay) {
    -webkit-animation: swing-in-left-bck .6s cubic-bezier(.175, .885, .32, 1.275) @delay both;
    animation: swing-in-left-bck .6s cubic-bezier(.175, .885, .32, 1.275) @delay both
}

.out(@delay) {
    -webkit-animation: fade-out .2s ease-out @delay both;
    animation: fade-out .2s ease-out @delay both
}

.baseKid {
    width: 50px;
    height: 50px;
    display: inline-block;
}


.selected
{
    .kid();
    color:yellow;
}

.kid {
    .out(0s);
    .baseKid();
}
.stashCard:hover .kid {
    .in(0s);
    .baseKid();
}

.stashCard:hover .kid.selected {
    .in(0s);
    .baseKid();
}
.stashCard:hover .kid2.selected {
    .in(0.05s);
    .baseKid();
}

.stashCard:hover .kid2 {
    .in(0.05s);
    .baseKid();
}

.stashCard:hover .kid3.selected {
    .in(0.1s);
    .baseKid();
}

.stashCard:hover .kid3 {
    .in(0.1s);
    .baseKid();
}

.hover {
    -webkit-animation: text-shadow-drop-center .6s both;
    animation: text-shadow-drop-center .6s both
}
.unhover {
    -webkit-animation: untext-shadow-drop-center .6s both;
    animation: untext-shadow-drop-center .6s both
}

这是我如何应用它的方式：

export const PopupMenu = (props: InputProps) => {
    return <div className="menu" style={props.style}>
        <VoteOption count="actors" className={props.selectedCounts.indexOf("actors") >= 0 ? "selected kid" : "kid"}  onClick={props.onClick} icon="sentiment_very_satisfied" tip="Real actors" />
        <VoteOption count="audio" className={props.selectedCounts.indexOf("audio") >= 0 ? "selected kid2" : "kid2"} onClick={props.onClick} icon="music_video" tip="Great audio quality" />
        <VoteOption count="picture" className={props.selectedCounts.indexOf("picture") >= 0 ? "selected kid3" : "kid3"} onClick={props.onClick} icon="photo_camera" tip="Great picture quality" />
    </div>;
}

显然这种方式效率低下，需要大量的复制和粘贴。有没有一种方法可以让我添加尽可能多的投票选项，而不需要编写迭代所有子组件并应用正确的偏移开始时间的css呢？

- meds

Answer 1

你可以使用循环来实现它：

.in(@delay) {
    -webkit-animation: swing-in-left-bck .6s cubic-bezier(.175, .885, .32, 1.275) @delay both;
    animation: swing-in-left-bck .6s cubic-bezier(.175, .885, .32, 1.275) @delay both
}

.out(@delay) {
    -webkit-animation: fade-out .2s ease-out @delay both;
    animation: fade-out .2s ease-out @delay both
}

.baseKid {
    width: 50px;
    height: 50px;
    display: inline-block;
}


.loop(@counter) when (@counter > 0) {
  .loop((@counter - 1));    // next iteration
  .kid@{counter} {
    .in(0.05s * (@counter - 1));
    .baseKid();
  }
  .kid@{counter}.seleted {
    width: (10px * @counter); // code for each iteration  
  }
}

.stashCard:hover {
  .loop(5); // launch the loop  
}

- Dat Tran