vue 点击加载更多

然后按照需求一步步来，先写基本页面

如果不想看过程，直接去后面完整代码那就可以

<template><div><div><div class="Journalism" ref="div"><div v-for="item in todos" :key="item.id" ref="show"><span>{{item.title}}</span><span>{{item.time}}</span></div></div><div class="JournalismShow">显示更多<i class="el-icon-arrow-down"></i></div></div></div>
</template>
<script>
export default {data(){return{todos:[{id:"1",title:"31省区市新增本土确诊80例、无症状21例",time:'2021-08-06'},{id:"2",title:"江苏新增本土确诊病例61例 其中扬州58例",time:'2021-08-06'},{id:"3",title:"因为这件事 美国又打脸谭德塞！",time:'2021-08-06'},{id:"4",title:"恶劣！拜登签署一份干涉港备忘录",time:'2021-08-06'},{id:"5",title:"巴萨官宣梅西正式离队",time:'2021-08-06'},{id:"6",title:"深圳甩出“王炸” 学区房炒作能否彻底“熄火”？",time:'2021-08-06'},{id:"7",title:"伊朗新总统刚就职 美国就喊话了",time:'2021-08-06'},{id:"8",title:"“全省最差场地” 全红婵儿时就在这里训练",time:'2021-08-06'},{id:"9",title:"湖北新增6例本土确诊、12例本土无症状",time:'2021-08-06'},{id:"10",title:"河南新增1例本土确诊、8例本土无症状",time:'2021-08-06'}],}},
}
</script><style scoped lang="scss">
.Journalism{width: 500px;div{display: flex;justify-content: space-between;span{height: 50px;font-size: 18px;color: #666;line-height: 50px;}}
}.JournalismShow{position: absolute;width: 500px;text-align: center;cursor:pointer;
}
</style>

效果：

后面只贴变化的代码

需求：默认显示5条其余点击显示更多后显示

<template><div><div><div class="Journalism" :class="{active:flag}" ref="div"><!-- 动态判断是否显示隐藏部分 --><div v-for="item in todos" :key="item.id" ref="show"><span>{{item.title}}</span><span>{{item.time}}</span></div></div><div class="JournalismShow" @click="showTag">显示更多<i :class="flag ? 'el-icon-arrow-down' :'el-icon-arrow-up'"></i></div><!-- 动态判断显示的图标 --></div></div>
</template>
<script>
export default {data(){return{flag:true}},methods:{//点击后切换状态showTag(){this.flag=!this.flag}}
}
</script><style scoped lang="scss">
//默认隐藏
.active{overflow: hidden;height: 250px;
}
</style>

页面效果：

写到现在我们可以发现css中高度是写死的，上边代码中的div高度都是一样的。

还有一种就是超出宽度换行显示，这种情况写死高度就会出现有可能某一行高度显示不完整

解决：

<template><div><div><!-- scss使用js变量 --><div :style="{'--divHeight':divHeight,'--showHeight':showHeight}" class="Journalism" :class="{active:flag}" ref="div"></div></div></div>
</template>
<script>
export default {data(){return{divHeight:"",showHeight:"",}},methods:{// 获取高度getHeight(){this.divHeight=this.$refs['div'].clientHeight+"px"let numb=0let arr=this.$refs['show']arr.forEach((item,index)=>{if(index<5){numb+=item.clientHeight}})this.showHeight=numb+'px'},},mounted(){this.getHeight()}
}
</script><style scoped lang="scss">
//默认隐藏
.active{overflow: hidden;height: var(--showHeight);
}
</style>

到现在页面基本完成，再设置下css样式就可了。本来是想用过渡的，但是过渡效果需要伪类激活，所以我们选择css动画

<style scoped lang="scss">
.Journalism{width: 500px;overflow: hidden;animation-name: examp;animation-duration: 1s;div{display: flex;justify-content: space-between;span{height: 50px;font-size: 18px;color: #666;line-height: 50px;}}
}
//默认隐藏
.active{overflow: hidden;height: var(--showHeight);animation-name: example;animation-duration: 1s;
}@keyframes example {from {height: var(--divHeight);}to {height: var(--showHeight);}
}
@keyframes examp {from {height: var(--showHeight);}to {height: var(--divHeight);}
}
</style>

页面效果

页面写到这里本来以为结束了，但是实验的时候就又发现了问题，刷新页面或者从其他页面跳到此页面后就会先执行了一次的动画，并且页面会闪烁一下。

我想要的是点击后才出现动画，解决的方式也是简单粗暴到让人窒息

<template><div><div class="top"><div :style="{'--divHeight':divHeight,'--showHeight':showHeight}" class="Journalism" :class="flag==0 ?  '' : (flag==1 ?  'active2' : 'active')" ref="div"><!-- 使用三目运算判断是否执行或执行某一个 --><div v-for="item in todos" :key="item.id" ref="show"><span>{{item.title}}</span><span>{{item.time}}</span></div></div><div class="JournalismShow" @click="showTag">显示更多<i :class="flag==1 ?  'el-icon-arrow-up' : 'el-icon-arrow-down'"></i></div><!-- 使用三目运算判断图标的方向 --></div></div>
</template>
<script>
export default {data(){return{// 开始的默认值flag:0,}},methods:{showTag(){// 使用if判断flag的值if(this.flag==0){this.flag=1}else if(this.flag==1){this.flag=2}else{this.flag=1}}}
}
</script><style scoped lang="scss">
.Journalism{width: 500px;overflow: hidden;height: var(--showHeight);div{display: flex;justify-content: space-between;span{height: 50px;font-size: 18px;color: #666;line-height: 50px;}}
}
.JournalismShow{position: absolute;width: 500px;text-align: center;cursor:pointer;
}
.active{overflow: hidden;height: var(--showHeight);animation-name: example;animation-duration: 1s;
}
.active2{height: var(--divHeight);animation-name: examp;animation-duration: 1s;
}@keyframes example {from {height: var(--divHeight);}to {height: var(--showHeight);}
}
@keyframes examp {from {height: var(--showHeight);}to {height: var(--divHeight);}
}
</style>

完整代码：

<template><div><div class="top"><div :style="{'--divHeight':divHeight,'--showHeight':showHeight}" class="Journalism" :class="flag==0 ?  '' : (flag==1 ?  'active2' : 'active')" ref="div"><div v-for="item in todos" :key="item.id" ref="show"><span>{{item.title}}</span><span>{{item.time}}</span></div></div><div class="JournalismShow" @click="showTag">显示更多<i :class="flag==1 ?  'el-icon-arrow-up' : 'el-icon-arrow-down'"></i></div></div></div>
</template>
<script>
export default {data(){return{todos:[{id:"1",title:"31省区市新增本土确诊80例、无症状21例",time:'2021-08-06'},{id:"2",title:"江苏新增本土确诊病例61例 其中扬州58例",time:'2021-08-06'},{id:"3",title:"因为这件事 美国又打脸谭德塞！",time:'2021-08-06'},{id:"4",title:"恶劣！拜登签署一份干涉港备忘录",time:'2021-08-06'},{id:"5",title:"巴萨官宣梅西正式离队",time:'2021-08-06'},{id:"6",title:"深圳甩出“王炸” 学区房炒作能否彻底“熄火”？",time:'2021-08-06'},{id:"7",title:"伊朗新总统刚就职 美国就喊话了",time:'2021-08-06'},{id:"8",title:"“全省最差场地” 全红婵儿时就在这里训练",time:'2021-08-06'},{id:"9",title:"湖北新增6例本土确诊、12例本土无症状",time:'2021-08-06'},{id:"10",title:"河南新增1例本土确诊、8例本土无症状",time:'2021-08-06'}],divHeight:'',showHeight:"250",flag:0,}},methods:{showTag(){if(this.flag==0){this.flag=1}else if(this.flag==1){this.flag=2}else{this.flag=1}},getHeight(){this.divHeight=this.$refs['div'].clientHeight+"px"let numb=0let arr=this.$refs['show']arr.forEach((item,index)=>{if(index<5){numb+=item.clientHeight}})this.showHeight=numb+'px'},},mounted(){this.getHeight()},
}
</script><style scoped lang="scss">
.Journalism{width: 500px;overflow: hidden;height: var(--showHeight);div{display: flex;justify-content: space-between;span{height: 50px;font-size: 18px;color: #666;line-height: 50px;}}
}
.JournalismShow{position: absolute;width: 500px;text-align: center;cursor:pointer;
}
.active{overflow: hidden;height: var(--showHeight);animation-name: example;animation-duration: 1s;
}
.active2{height: var(--divHeight);animation-name: examp;animation-duration: 1s;
}@keyframes example {from {height: var(--divHeight);}to {height: var(--showHeight);}
}
@keyframes examp {from {height: var(--showHeight);}to {height: var(--divHeight);}
}
</style>

如果大家有更好的方法，欢迎告知！！！