Carousel组件
# 原理
直接添加的节点,操作追加dom; 定时移除节点;
# 实现
# 入口
carousel/index.js
import Carousel from './carousel'
import '../../style/carousel.scss'
Carousel.install = (app) => {
app.component(Carousel.name, Carousel)
}
export default Carousel
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# 属性封装
carousel-props.js
export default {
height: {
type: String, // 200px
default: "200px",
},
autoplay: {
type: Boolean,
default: true,
},
delay: {
type: Number,
default: 3000,
},
initialIndex: {
type: Number,
default: 0,
},
loop: {
type: Boolean,
default: true,
},
}
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使用
import props from "./carousel-props";
export default {
// $children
name: "RCarousel",
props,
}
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# 设置滚动
- 控制临界点;
- 鼠标处理;
- 自动滚动处理;
- 底部及切换;
const methods = {
handleMouseEnter() {
clearInterval(timer);
timer = null;
},
handleMouseLeave() {
methods.run();
},
go(newIndex, flag) {
// 临界条件 到了最后一张的下一张是第一张 第一张的前一张是最后一张
let index = state.currentSelected;
if (newIndex == state.len) newIndex = 0;
if (newIndex == -1) newIndex = state.len - 1;
// 根据上一次的值和当前值 做一个运算 判断是正向还是反向
state.reverse = index > newIndex ? true : false;
// 3 => 0 正 0=》3 反
if ((timer || flag) && props.loop) {
// 如果是自动轮播 处理最后的边界条件
if (index == 0 && newIndex == state.len - 1) {
state.reverse = true;
}
if (index == state.len - 1 && newIndex == 0) {
state.reverse = false;
}
}
nextTick(() => {
state.currentSelected = newIndex; // 保证样式的reverse 已经添加到dom上了 在去更新状态
});
},
run() {
// 默认运行逻辑
if (props.autoplay) {
// 是否需要自动轮播
timer = setInterval(() => {
let index = state.currentSelected;
let newIndex = index - 1;
methods.go(newIndex);
}, props.delay);
}
},
};
onMounted(() => {
state.len = state.currentIndex;
methods.run();
});
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# item处理
<template>
<!-- carousel-enter-acitve enter to... -->
<transition name="carousel">
<div class="r-carousel-item" v-if="isVisible" :class="classs">
<slot></slot>
</div>
</transition>
</template>
<script>
import { computed, inject } from "vue";
export default {
name: "RCarouselItem",
setup() {
let { state, changeIndex } = inject("current");
let currentIndex = state.currentIndex; // 这个是插槽对应的索引 carousel-item
let isVisible = computed(() => {
// currentSelected 当前要显示哪一个
return state.currentSelected == currentIndex;
});
let classs = computed(() => [state.reverse ? "reverse" : ""]);
changeIndex();
return {
isVisible,
classs,
};
},
};
</script>
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# 父子组件通讯
provide("current", { state, changeIndex }); // provide 经常在插件中使用;在子item会用到
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export default {
name: "RCarouselItem",
setup() {
let { state, changeIndex } = inject("current");
let currentIndex = state.currentIndex; // 这个是插槽对应的索引 carousel-item
let isVisible = computed(() => {
// currentSelected 当前要显示哪一个
return state.currentSelected == currentIndex;
});
let classs = computed(() => [state.reverse ? "reverse" : ""]);
changeIndex();
return {
isVisible,
classs,
};
},
};
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# carousel-item
单独抽取实现
import CarouselItem from '../carousel/carousel-item'
import '../../style/carousel-item.scss'
CarouselItem.install = (app) => {
app.component(CarouselItem.name,CarouselItem)
}
export default CarouselItem
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上次更新: 2022/04/15, 05:41:28