reactive
用来绑定复杂的数据类型 例如 对象 数组
他是不可以绑定普通的数据类型这样是不允许 会给我们报错
import { reactive} from 'vue'
let person = reactive('sad')
绑定普通的数据类型 可以使用ref
使用reactive 去修改值无须.value
reactive 基础用法:
import { reactive } from 'vue'
let person = reactive({
name:"小强"
})
person.name = "大强"
数组异步赋值问题
这样赋值页面是不会变化的因为会脱离响应式
let person = reactive<number[]>([])
setTimeout(() => {
person = [1, 2, 3]
console.log(person);
},1000)
解决方案1:用push
import { reactive } from 'vue'
let person = reactive<number[]>([])
setTimeout(() => {
const arr = [1, 2, 3]
person.push(...arr)
console.log(person);
},1000)
解决方案2:包裹一层对象
type Person = {
list?:Array<number>
}
let person = reactive<Person>({
list:[]
})
setTimeout(() => {
const arr = [1, 2, 3]
person.list = arr;
console.log(person);
},1000)
readonly
拷贝一份proxy对象将其设置为只读
import { reactive ,readonly} from 'vue'
const person = reactive({count:1})
const copy = readonly(person)
//person.count++
copy.count++
shallowReactive
只能对浅层的数据响应式 如果是深层的数据只会改变值 不会改变视图
<template>
<div>
<div>{{ state }}</div>
<button @click="change1">test1</button>
<button @click="change2">test2</button>
</div>
</template>
<script setup lang="ts">
import { shallowReactive } from 'vue'
const obj = {
a: 1,
first: {
b: 2,
second: {
c: 3
}
}
}
const state = shallowReactive(obj)
function change1() {
state.a = 7
}
function change2() {
state.first.b = 8
state.first.second.c = 9
console.log(state);
}
</script>
<style>
</style>
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