ref

ref 变为响应式数据
shallowRef 浅层响应式数据（响应式到 .value为止）
isRef 判断是否为ref响应式数据
triggerRef 强制触发依赖更新
customRef 自定义ref函数

<template>
  <div class="App">
    {{ stu }}
    <button @click="changeRefStu">ref测试</button>

    {{ stu2 }}
    <button @click="changeShallowRef">shallowRef测试</button>
    <button @click="changeShallowRef2">triggerRef测试</button>

    {{ stu3 }}
    <button @click="changeCustomRef">customRef测试</button>
  </div>
</template>

<script setup lang="ts">
import { ref, isRef, shallowRef, triggerRef, customRef } from "vue";

// 1.ref 改变数据，自动触发依赖更新
const stu = ref({ name: "cjc" });

function changeRefStu() {
  stu.value.name = "CCC";
  console.log("stu", stu.value);
  // isRef
  console.log("isRef(stu)", isRef(stu));
}

// 2. shallowRef 浅层响应式
const stu2 = shallowRef({ name: "cjc" });
function changeShallowRef() {
  // 修改不成功，浅层shallowRef的响应式到 .value为止
  // 故 stu2.value.name = "stu2"; 无法更新视图
  stu2.value = { name: "CCC" };
  console.log("stu2", stu2.value);
  // isRef
  console.log("isRef(stu2)", isRef(stu2));
}

function changeShallowRef2() {
  stu2.value.name = "stu2";
  // 强制触发依赖更新
  triggerRef(stu2);
  console.log("stu2", stu2.value);
}

// 3. customRef 自定义响应式数据
function MyRef<T>(value: T) {
  return customRef((track, trigger) => {
    return {
      get() {
        // track收集依赖
        track();
        return value;
      },
      set(newVal: T) {
        value = newVal;
        // 强制触发依赖更新
        trigger();
      },
    };
  });
}
const stu3 = MyRef({ name: "cjc" });
function changeCustomRef() {
  // stu3.value.name = "CCC";
  stu3.value = { name: "CCC" };
  console.log("stu3", stu3.value);
}
</script>

<style scoped></style>

reactive

reactive 变为响应式数据（只能将引用类型转换为响应式：对象、数组、set、map）
shallowReactive 浅层响应式数据（响应式到第一层属性为止）

ref与reactive区别：
reactive 取值、改值不用.value解包

1.对象

<template>
  <div class="App">
    <form>
      <div>
        姓名：<input type="text" v-model="formData.name" name="" id="" />
        <p>{{ formData.name }}</p>
      </div>
      <div>
        年龄：<input type="text" v-model="formData.age" name="" id="" />
        <p>{{ formData.age }}</p>
      </div>
      <button @click.prevent="commit">提交</button>
    </form>
  </div>
</template>

<script setup lang="ts">
import { reactive } from "vue";

// reactive 将引用类型转换为响应式
// 对象、数组、set、map
const formData = reactive({
  name: "ccc",
  age: "999",
});
function commit() {
  console.log("formData", formData);
}
</script>

<style scoped></style>

2.数组
给reactive包裹的响应式数组直接赋值为普通数组，会失去响应式

<template>
  <div class="App">
    {{ arr }}
    <button @click="addItem">arr.push()</button>
  </div>
</template>

<script setup lang="ts">
import { reactive } from "vue";

let arr = reactive([1, 2]);
console.log("arr", arr);

// arr直接赋值为数组，失去响应式
// arr = [1, 2, 3];
// console.log("arr", arr);

// 保持响应式方法1 push
function addItem() {
  arr.push(3);
  console.log("arr", arr);
}
</script>

<style scoped></style>

3.shallowReactive

<template>
  <div class="App">
    {{ obj }}
    <button @click="changeObj1">修改obj.a.b.c</button>
    <button @click="changeObj2">修改obj.a</button>
  </div>
</template>

<script setup lang="ts">
import { ref, reactive, shallowReactive } from "vue";
const obj = shallowReactive({
  a: {
    b: {
      c: "cjc",
    },
  },
});

console.log("obj修改前", obj);

function changeObj1() {
  obj.a.b.c = "CCC";
  console.log("changeObj1修改后", obj);
}

function changeObj2() {
  obj.a = {
    b: {
      c: "CCC666",
    },
  };
  console.log("changeObj2修改后", obj);
}
</script>

<style scoped></style>

在这里插入图片描述

toRef、toRefs、toRaw

toRef 将响应式对象的指定属性变为响应式（对非响应式对象没用）
toRefs 将响应式对象的所有属性变为响应式
toRaw 返回由 reactive()、readonly()、shallowReactive() 或者 shallowReadonly() 创建的代理对应的原始对象

<template>
  <div class="APP">{{ obj.name }}-{{ obj.age }}</div>
</template>

<script setup lang="ts">
import { ref, reactive, toRef, toRefs } from "vue";
const obj = reactive({
  name: "cjc",
  age: 100,
  hobbies: [1, 2, 3],
});

// 0.打印reactive响应式数据的属性
console.log("name", obj.name);
console.log("age", obj.age);
console.log("hobbies", obj.hobbies);

// 1.将响应式对象obj的指定属性name变为ref响应式
const name = toRef(obj, "name");
console.log("name", name);

// 2.将响应式对象obj的所有属性变为ref响应式
const { age, hobbies } = toRefs(obj);
console.log("age", age);
console.log("hobbies", hobbies);
</script>

<style scoped></style>