1、只能用watch的方式做吗？
2、为什么不用输入框的input事件，比如这样写

<template>
    <div class="search-input">
        <i class="icon-search"></i>
        <input class="input-inner" v-model="query" @input="changeInput">
        <i class="icon-dismiss"></i>
    </div>
</template>
<script>
import { debounce } from 'throttle-debounce';
export default {
    name: 'search-input',
    props: {
        modelValue: String
    },
    data() {
        return {
            query: this.modelValue
        }
    },
    methods: {
        changeInput:debounce(300, function(e) {
            const val = e.target.value.trim();
            this.$emit('update:modelValue', val.trim())
        })
    },
}