最近有个转盘抽奖的需求，搜了一下现有的轮子，有的是用jQuery的动画函数实现的，有的是用canvas绘图然后再用高频率的setTimeout调用旋转方法，前者太老了没法简单移植到vue项目，后者感觉性能表现可能不会太好。也有一些用CSS动画的方案，设计了加速-匀速-减速三个动画，再计算偏转角度让三个动画尽可能无缝衔接，但我感觉绕了大远路，应该有更简单轻量的实现方案。个人更倾向于用transition来实现，不过网上的例子感觉还不够好，有的倾斜文字都没有对齐，最后还是自己手写了一个。
无需jQuery，不用js脚本实现动画细节，动画效果完全连续无需衔接，支持动态设置2个以上任意数量的奖项。
核心思路是用transition以及rotate实现旋转动画，使用transition-origin和rotate绘制出定位较为精确的轮盘奖项。
<script src="//unpkg.com/vue/dist/vue.js"></script>
<span id="app">
<span>Prize number: {{ prizeNumber }}</span>
<button type="button" @click="!rolling && prizeNumber < 8 && (prizeNumber++)" :disabled="rolling || prizeNumber === 8">Add</button>
<button type="button" @click="!rolling && prizeNumber > 2 && (prizeNumber--)" :disabled="rolling || prizeNumber === 2">Remove</button>
<div class="wheel-wrapper">
<div
class="wheel-pointer"
@click="onClickRotate"
>
Start
</div>
<div
class="wheel-bg"
:class="{freeze: freeze}"
:style="`transform: rotate(${wheelDeg}deg)`"
>
<div class="prize-list">
<div
class="prize-item-wrapper"
v-for="(item,index) in prizeList"
:key="index"
>
<div
class="prize-item"
:style="`transform: rotate(${(360/ prizeList.length) * index}deg)`"
>
<div class="prize-name">
{{ item.name }}
</div>
<div class="prize-icon">
<img :src="item.icon">
</div>
</div>
</div>
</div>
</div>
</div>
</div>
html {
background: #DD7C7D;
}
.wheel-wrapper {
width: 300px;
height: 300px;
position: absolute;
top: 50%;
left: 50%;
transform: translate(-50%, -50%);
}
.wheel-pointer {
width: 60px;
height: 60px;
border-radius: 1000px;
background: yellow;
position: absolute;
left: 50%;
top: 50%;
transform: translate(-50%, -50%);
text-align: center;
line-height: 60px;
z-index: 10;
}
.wheel-bg {
width: 100%;
height: 100%;
border-radius: 1000px;
overflow: hidden;
transition: transform 4s ease-in-out;
background: #7EEF97;
&.freeze {
transition: none;
background: red;
}
}
.prize-list {
width: 100%;
height: 100%;
position: relative;
text-align: center;
}
.prize-item-wrapper {
position: absolute;
top: 0;
left: 50%;
transform: translateX(-50%);
width: 150px;
height: 150px;
}
.prize-item {
width: 100%;
height: 100%;
transform-origin: bottom;
.prize-name {
padding: 16px 0;
}
.prize-icon {}
}
var Main = {
data() {
return {
freeze: false,
rolling: false,
wheelDeg: 0,
prizeNumber: 8,
prizeListOrigin: [
{
icon: "https://picsum.photos/40?random=1",
name: "$10000"
},
{
icon: "https://picsum.photos/40?random=6",
name: "Thank you!"
},
{
icon: "https://picsum.photos/40?random=2",
name: "$500"
},
{
icon: "https://picsum.photos/40?random=3",
name: "$100"
},
{
icon: "https://picsum.photos/40?random=6",
name: "Thank you!"
},
{
icon: "https://picsum.photos/40?random=4",
name: "$50"
},
{
icon: "https://picsum.photos/40?random=5",
name: "$10"
},
{
icon: "https://picsum.photos/40?random=6",
name: "Thank you!"
}
]
};
},
computed: {
prizeList () {
return this.prizeListOrigin.slice(0, this.prizeNumber)
}
},
methods: {
onClickRotate() {
if (this.rolling) {
return;
}
this.rolling = true;
const { wheelDeg, prizeList } = this;
const random = Math.floor(Math.random() * (prizeList.length ));
console.log(random);
this.wheelDeg =
wheelDeg -
wheelDeg % 360 +
6 * 360 +
(360 - 360 / prizeList.length * random);
setTimeout(() => {
this.rolling = false;
alert("Result：" + prizeList[random].name);
}, 4500);
}
},
watch: {
prizeNumber () {
this.freeze = true
this.wheelDeg = 0
setTimeout(() => {
this.freeze = false
}, 0)
}
}
};
var App = Vue.extend(Main);
new App().$mount("#app");
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持脚本之家。
