Vite+Typescript+Vue3学习笔记

1、项目搭建

1.1、创建项目(yarn)

D:\WebstromProject>yarn create vite
yarn create v1.22.19
[1/4] Resolving packages...
[2/4] Fetching packages...
[3/4] Linking dependencies...
[4/4] Building fresh packages...success Installed "create-vite@4.4.1" with binaries:- create-vite- cva
√ Project name: ... vite-project
√ Select a framework: » Vue
√ Select a variant: » TypeScriptScaffolding project in D:\WebstromProject\vite-project...Done. Now run:cd vite-projectyarnyarn devDone in 14.81s.

1.2、项目配置

1、配置vue文件识别

vite默认情况下不识别.vue后缀的文件，需在vite-env.d.ts配置下

/// <reference types="vite/client" />
declare module "*.vue" {import { DefineComponent } from "vue"const component: DefineComponent<{}, {}, any>export default component
}

2、Api选择

/* Options API */
export default {props: {},data(){},computed: {},watch: {},methods: {},created(),components:{}// ...other options
}

/* Composition API */
export default {props: {},setup(),components:{}
}

Vue3推荐使用Composition API，这里关闭Vue2的Option Api

import {defineConfig} from 'vite'
import vue from '@vitejs/plugin-vue'// https://vitejs.dev/config/
export default defineConfig({define: {// 关闭Vue2 Options Api__VUE_OPTIONS_API__: false},plugins: [vue(),],
})

1.3、常用依赖

1、@types/node

ts需安装node的类型，否则使用node相关会提示找不到

# @types/node
yarn add -D @types/node

2、auto-import

用于简化Vue3中ref、reactive**、**watch和UI组件的导入

# unplugin-vue-components、unplugin-auto-import
yarn add -D unplugin-vue-components unplugin-auto-import

3、sass

# sass
yarn -D add sass

2、Composition API

2.1、响应式

可以在chrome浏览器开启自定义格式化，便于查看

1、ref

ref通常用于声明基础类型响应式数据，引用类型也可以，会隐式调用reactive，同时取值赋值都需要.value

<script setup lang="ts">
import {Ref} from "vue";
// 非响应式
// let number: number = Math.random()
// console.log(isRef(number))// 响应式
// let number = ref(Math.random())
// 显式类型约束
let number: Ref<number> = ref<number>(Math.random())
console.log(isRef(number))
const h1click = () => {// 非响应式// number = Math.random()// 响应式number.value = Math.random()console.log(number);
}
</script><template><div><h1 @click="h1click">{{ number }}</h1></div>
</template><style scoped></style>

2、shallowRef

只处理基本数据类型的响应式, 不进行对象的响应式处理（不能与ref一起用，否则会被迫更新视图）

<script setup lang="ts">
import {isShallow, Ref} from "vue";let number = shallowRef<number>(Math.random())
console.log(isShallow(number))
const h1click = () => {number.value = Math.random()console.log(number);
}
</script><template><div><h1 @click="h1click">{{ number }}</h1></div>
</template><style scoped></style>

3、reactive

reactive用于声明引用类型响应式数据，且对象解构后会失去响应式

<script setup lang="ts">let person = reactive({name: "xumeng"
})
console.log(isReactive(person))
const h1click = () => {person.name = "xumeng03"console.log(person);
}
</script><template><div><h1 @click="h1click">{{ person }}</h1></div>
</template><style scoped></style>

4、shallowReactive

只处理对象最外层属性的响应式（浅响应式）,（不能与reactive一起用，否则会被迫更新视图）

<script setup lang="ts">let person = shallowReactive({name: "xumeng",hobby: ["game","code"]
})
console.log(isReactive(person))
const h1click = () => {// 浅层次数据// person.name = "xumeng03"// 深层次数据（如果浅层次&深层次数据一起变化，则会一起更新）person.hobby[0] = 'movie'console.log(person);
}
</script><template><div><h1 @click="h1click">{{ person }}</h1></div>
</template><style scoped></style>

5、toRef

将对象某个属性变为响应式

<script setup lang="ts">let person = reactive({name: "xumeng"
})
// 如果person非响应式对象，则不会引起视图更新
let name = toRef(person, 'name')
const h1click = () => {name.value = "xumeng03"console.log(person);
}
</script><template><div><h1 @click="h1click">{{ person }}</h1></div>
</template><style scoped></style>

6、toRefs

将对象的一些解构属性变为响应式

<script setup lang="ts">let person = reactive({name: "xumeng",age: 22
})
// 解构别名
let {name: pname, age: page} = toRefs(person)
const h1click = () => {pname.value = "xumeng03"page.value = 23console.log(pname, page);
}
</script><template><div><h1 @click="h1click">{{ person }}</h1></div>
</template><style scoped></style>

7、toRaw

把响应式对象变为普通对象

<script setup lang="ts">let person = reactive({name: "xumeng",age: 22
})let rperson = toRaw(person)
const h1click = () => {rperson.name = "xumeng03"rperson.age = 23console.log(rperson);
}
</script><template><div><h1 @click="h1click">{{ person }}</h1></div>
</template><style scoped></style>

2.2、修饰符

1、readonly

<script setup lang="ts">let person = reactive({name: "xumeng"
})
let rperson = readonly(person)
const h1click = () => {// 正常赋值person.name = "xumeng03"// 报错// rperson.name = "xumeng03"console.log(person);
}
</script><template><div><h1 @click="h1click">{{ person }}</h1></div>
</template><style scoped></style>

2.3、computed

1、选项式写法

参数为对象，需传入一个get和set函数自定义存取操作

<script setup lang="ts">let person = reactive({name: "xumeng03",nickName: '眼眸流转',age: 22
})
let people = computed({get() {return person.name + '-' + person.nickName},set(newValue) {[person.name, person.nickName] = newValue.split('-')}
})
const h1click = () => {people.value = '徐梦-眼眸'
}
</script><template><div><h1 @click="h1click">{{ people }}</h1></div>
</template><style scoped></style>

2、函数式写法

<script setup lang="ts">let person = reactive({name: "xumeng03",nickName: '眼眸流转',age: 22
})
let people=computed(()=>{return person.name + '-' + person.nickName
})
const h1click = () => {// 不支持修改// people.value = '徐梦-眼眸'
}
</script><template><div><h1 @click="h1click">{{ people }}</h1></div>
</template><style scoped></style>

2.4、监听

1、watch

基本类型

<script setup lang="ts">let age = ref(22)
const h1click = () => {age.value++
}
watch(age, (value, oldValue) => {console.log("监听到变化：", value, oldValue);
})
</script><template><div><h1 @click="h1click">{{ age }}</h1></div>
</template><style scoped></style>

引用类型

<script setup lang="ts">let person = reactive({name: "xumeng03",nickName: '眼眸流转',age: 22
})
let person1 = reactive({name: "xumeng03",nickName: '眼眸流转',age: 22
})
const h1click = () => {person.age++
}
let people = computed(() => {return person.name + '-' + person.nickName + '-' + person.age
})// 此时若监听person会发现新旧数据一致，可以使用computed处理一下返回（如返回新的信息或深拷贝原引用数据）
// watch(person, (value, oldValue) => {
//     console.log("监听到变化：", value, oldValue);
// }, {
//     // 深度监听，reactive默认就是深度监听
//     deep: true,
//     // 立即执行一次
//     immediate: true,
//     // 刷新时机
//     flush: 'pre'
// })// 监听整个引用数据
watch(people, (value, oldValue) => {console.log("监听到变化：", value, oldValue);
}, {// 深度监听，reactive默认就是深度监听deep: true,// 立即执行一次immediate: true,// 刷新时机flush: 'pre'
})// 监听引用对象某个属性
watch(() => person.age, (value, oldValue) => {console.log("监听到变化：", value, oldValue);
}, {// 深度监听，reactive默认就是深度监听deep: true,// 立即执行一次immediate: true,// 刷新时机flush: 'pre'
})// 监听多个数据源
watch([person, person1], (value, oldValue) => {console.log("监听到变化：", value, oldValue);
}, {// 深度监听，reactive默认就是深度监听deep: true,// 立即执行一次immediate: true,// 刷新时机flush: 'pre'
})
</script><template><div><h1 @click="h1click">{{ people }}</h1></div>
</template><style scoped></style>

2、watchEffect

 <script setup lang="ts">let age = ref(22)
const h1click = () => {age.value++
}
// watchEffect返回一个停止监听函数
const stopwatch = watchEffect((oninvalidate) => {oninvalidate(() => {console.log("变化前");})console.log(age);
})
// 停止监听
// stopwatch()
</script><template><div><h1 @click="h1click">{{ age }}</h1></div>
</template><style scoped></style>

2.5、生命周期

<script setup lang="ts">
let age = ref(22)
let h1 = ref<HTMLElement>()
// 生命周期（setup模式下无beforeCreate和created）// 挂载前
onBeforeMount(() => {console.log('挂载前', h1.value);
})
// 挂载完成
onMounted(() => {console.log('挂载完成', h1.value);
})// 更新前
onBeforeUpdate(() => {console.log('更新前', h1.value?.innerText);
})
// 更新完成
onUpdated(() => {console.log('更新完成', h1.value?.innerText);
})// 销毁前
onBeforeUnmount(() => {console.log('销毁前');
})
// 销毁后
onBeforeUnmount(() => {console.log('销毁后');
})
const h1click = () => {age.value++
}
</script><template><div><h1 @click="h1click" ref="h1">{{ age }}</h1></div>
</template><style scoped></style>

2.6、父子组件传参

1、父传子（defineProps）

父组件

<script setup lang="ts">
let PtoC1 = ref(1)
let PtoC2 = ref({name: 'xumeng03',age: 22
})
</script><template><div>我是父组件<hr><Child :PtoC1="PtoC1" :PtoC2="PtoC2"/></div>
</template><style scoped lang="scss"></style>

子组件

<script setup lang="ts">
// js形式
// const props = defineProps({
//     PtoC1: {
//         type: Number,
//         default: '默认值'
//     },
//     PtoC2: {
//         type: Object,
//         default: {}
//     }
// })// typescript类型约束
const props = defineProps<{PtoC1: number,PtoC2: {name: string,age: number}
}>()// typescript默认值
withDefaults(defineProps<{PtoC1: number,PtoC2: {name: string,age: number}
}>(), {PtoC1: 0, PtoC2: () => ({name: 'name', age: 0})
})
</script><template><div>我是子组件<br><!--来自父组件的消息1: {{ FtoC }}-->来自父组件的消息1: {{ props.PtoC1 }}<br>来自父组件的消息2: {{ props.PtoC2 }}</div>
</template><style scoped lang="scss"></style>

2、子传父（defineEmits）

父组件

<script setup lang="ts">
let Pmessage1 = ref<string>()
let Pmessage2 = reactive<{name: string,age: number
}>({name: 'name',age: 0
})
const getChildMessage1 = (message: string) => {Pmessage1.value = message
}
const getChildMessage2 = (message: {name: string,age: number
}) => {Pmessage2 = message
}
</script><template><div>我是父组件<br>来自父组件的消息1: {{ Pmessage1 }}<br>来自父组件的消息1: {{ Pmessage2 }}<hr><Child @getChildMessage1="getChildMessage1" @getChildMessage2="getChildMessage2"/></div>
</template><style scoped lang="scss"></style>

子组件

<script setup lang="ts">
let message1 = ref("xumeng03")
let message2 = reactive({name: 'xumeng03',age: 22
})
// const emit = defineEmits(['getChildMessage1', 'getChildMessage2'])
const emit = defineEmits<{(e: 'getChildMessage1', message: string): void,(e: 'getChildMessage2', message: {name: string,age: number}): void
}>()
const transValue = () => {emit('getChildMessage1', message1.value)emit('getChildMessage2', message2)
}
</script><template><div @click="transValue">我是子组件</div>
</template><style scoped lang="scss"></style>

3、父组件访问子组件

父组件

<script setup lang="ts">
import Child from "@/components/Child.vue";const child1 = ref<InstanceType<typeof Child>>()
const childAttributes = () => {console.log(child1.value.username)child1.value.changeName('xumeng03' + Math.ceil(Math.random() * 10))
}
</script><template><div @click="childAttributes">我是父组件<br>子组件属性：{{ child1 }}<hr><Child ref="child1"/></div>
</template><style scoped lang="scss"></style>

子组件

<script setup lang="ts">
let username = ref("child")
const changeName = (newName: string) => {console.log("newName:" + newName)username.value = newName
}defineExpose({username,changeName
})
</script><template><div>我是子组件</div>
</template><style scoped lang="scss"></style>

3、样式

3.1、全局样式/变量

@/style/variables.scss

$theColor: lightblue;h1 {font-size: 100px;
}

vite.config.ts

import {defineConfig} from 'vite'
import vue from '@vitejs/plugin-vue'
import path from 'path'
// 自动导入vue中ref、reactive、watch等
import AutoImport from "unplugin-auto-import/vite"
// 自动导入ui组件
import Components from 'unplugin-vue-components/vite';// https://vitejs.dev/config/
export default defineConfig({define: {// 关闭Vue2 Options Api__VUE_OPTIONS_API__: false},plugins: [vue(),AutoImport({// 在组件中不用再导入ref、reactive、watch等imports: ['vue', 'vue-router'],// 声明文件存放的位置，会自动生成，无需自己维护dts: "src/auto-import.d.ts",}),Components({// 引入组件的存放的位置,包括自定义组件dts: "src/components.d.ts",}),],resolve: {// 配置路径别名alias: {"@": path.resolve(__dirname, "./src"),},},css: {preprocessorOptions: {scss: {additionalData: `@import "@/style/variables.scss";`}}},
})

使用

<script setup lang="ts">
let age = ref(22)
const h1click = () => {age.value++
}
</script><template><div><h1 @click="h1click">年龄：{{ age }}</h1></div>
</template>
<!--注意style必须加上lang="scss"-->
<style scoped lang="scss">
h1 {color: $theColor;
}
</style>