Vue原生写全选反选框

效果

场景：Vue全选框在头部，子框在v-for循环内部。
实现：点击全选框，所有子项选中，再次点击取消；子项全选中，全选框自动勾选，子项并未全选，全选框不勾选；已选和全选数量统计；

实现

#1. html

<div class="checkall" :class="isCheck?'active':''" @click="clickAll"></div><span>全选</span><div class="card" v-for="(item, index) in tableData" :key="index"><div class="checkitem" :class="item.isCheck?'active':''" @click="clickItem(item.id)"></div>
</div>

#2. js

data() {return {tableData: [],isCheck:false,Selected: 0,SelectAll: 0,}},
mounted:{this.init();
}
methods:{async init(){let res = await ...; //请求this.tableData = res.datathis.SelectAll = res.data.length;this.tableData = this.tableData.map(item => {item.isCheck = falsereturn item})},clickItem(id){this.tableData.forEach(v=>{v.id == id ? v.isCheck = !v.isCheck : ''})this.Selected = this.tableData.filter(i=>i.isCheck).length; if(this.Selected == this.SelectAll){this.isCheck = true;}else{this.isCheck?this.isCheck=false:'';}},clickAll(){this.isCheck = !this.isCheck;if(this.isCheck){this.tableData.forEach(v=>{v.isCheck = true;})}else{this.tableData.forEach(v=>{v.isCheck = false;})}this.Selected = this.tableData.filter(i=>i.isCheck).length;}
}

#3. css

.checkall{height: .16rem;width: .16rem;border-radius: 0.02rem;border: 1px solid #1E77F5;margin-right: .06rem;
}
.checkall.active{background-color: #1E77F5;}.checkitem{position: absolute;top: .16rem;right: .16rem;height: .16rem;width: .16rem;border-radius: 0.02rem;border: 1px solid #1E77F5;margin-right: .06rem;z-index: 1;
}
.checkitem.active{background-color: #1E77F5;
}

#完整代码：

<div class="checkall" :class="isCheck?'active':''" @click="clickAll"><span class="icon iconfont" style="color:#fff;" v-show="isCheck">&#xe715;</span>
</div><span>全选</span><div class="card" v-for="(item, index) in tableData" :key="index"><div class="checkitem" :class="item.isCheck?'active':''" @click="clickItem(item.id)"><span class="icon iconfont" style="color:#fff;" v-show="item.isCheck">&#xe715;</span></div>
</div>
...
data() {return {tableData: [],isCheck:false,Selected: 0,SelectAll: 0,}},
mounted:{let res = await ...; //请求后端接口this.tableData = res.datathis.SelectAll = res.data.length;this.tableData = this.tableData.map(item => {item.isCheck = falsereturn item})
}
methods:{clickItem(id){this.tableData.forEach(v=>{v.id == id ? v.isCheck = !v.isCheck : ''})this.Selected = this.tableData.filter(i=>i.isCheck).length; //选完统计一下选中个数，同时调用this.tableData本身可以让视图及时更新，不再调用会出现选中没效果if(this.Selected == this.SelectAll){this.isCheck = true;}else{this.isCheck?this.isCheck=false:'';}},clickAll(){this.isCheck = !this.isCheck;if(this.isCheck){this.tableData.forEach(v=>{v.isCheck = true;})}else{this.tableData.forEach(v=>{v.isCheck = false;})}this.Selected = this.tableData.filter(i=>i.isCheck).length;}
}
...
.checkall{height: .16rem;width: .16rem;border-radius: 0.02rem;border: 1px solid #1E77F5;margin-right: .06rem;
}
.checkall.active{background-color: #1E77F5;}.checkitem{position: absolute;top: .16rem;right: .16rem;height: .16rem;width: .16rem;border-radius: 0.02rem;border: 1px solid #1E77F5;margin-right: .06rem;z-index: 1;
}
.checkitem.active{background-color: #1E77F5;
}