pinia的使用

忘是亡心i 2024-04-01 12:29 24阅读 0赞

## 1.安装安装pinia ##

[pinia][]

#### 1.1 安装命令 ####

npm install pinia
    # 或者使用 yarn
    yarn add pinia
    # 或者使用 cnpm
    cnpm install pinia

#### 1.2 代码如下: ####

// main.js
    
    import {
         createApp } from "vue";
    import App from "./App.vue";
    import {
         createPinia } from "pinia";
    const pinia = createPinia();
    
    const app = createApp(App);
    app.use(pinia);
    app.mount("#app");

## 2.创建store ##

#### 2.1 代码如下: ####

/src/store/index.js
    
    import {
         defineStore } from 'pinia'
    
    //参数是 store 的唯一 id
    export const useStore = defineStore('main', {
        
      state: () => {
        
        return {
        
          count: 0,
          name: "张三"
        }
      }
    })

#### 2.2.使用store ####

/src/App.vue
    
    <template>
      <div>
        {
        {
         count }}
        <br />
        <n-button type="primary" @click="changeNum()"> + </n-button>
        <br />
        {
        {
         name }}
        <br />
        <n-button type="primary" @click="changeName()"> 改名 </n-button>
        <br />
        <n-button type="primary" @click="patchStore()"> 批量修改 </n-button>
      </div>
    </template>
    
    <script setup lang="ts">
    import {
         useStore } from "../stores/index";
    const state = useStore();
    import {
         storeToRefs } from "pinia";
    // const { count,name }=state;//页面数据无需更改时使用,不是响应式。
    const {
         count, name } = storeToRefs(state); //页面数据需要更改时使用,storeToRefs函数将state中的数据变为响应式。
    const changeNum = () => {
        
      state.count += 1;
    };
    const changeName = () => {
        
      state.name = "李四";
    };
    const patchStore = () => {
        
      //store的$patch进行批量修改
      state.$patch({
        
        count: 1,
        name: "王五",
      });
    };
    </script>

## 3.getters属性 ##

类似于Vue中的computed计算属性，作用就是返回一个新的结果。

/src/store/index.js
    
    import {
         defineStore } from 'pinia'
    export const useStore = defineStore('main', {
        
      state: () => {
        
        return {
        
          count: 0,
          name: "张三"
        }
      },
      getters: {
        
        //直接在getter方法中调用this，this指向的便是store实例
        getCount: (state) => {
        
          return state.count + 666;
        },
        getName: (state) => {
        
          return state.name + "666";
        },
    
        //调用其他getters,不使用箭头函数
        getNamePlus() {
        
          return this.name + this.getNum;
        }
      }
    })

/src/App.vue
    
    <template>
      <div>
        {
        {
         state.getCount }}
        <br/>
        {
        {
         state.getName }}
        <br/>
        {
        {
         state.getNamePlus }}
      </div>
    </template>
    
    <script setup lang="ts">
    import {
         useStore } from "../stores/index";
    const state = useStore();
    </script>

## 4.actions属性 ##

类似于Vue中的methods方法属性,用来放置一些处理业务逻辑的方法,包括同步方法和异步方法。

/src/store/index.js
    
    import {
         defineStore } from 'pinia'
    export const useStore = defineStore('main', {
        
      state: () => {
        
        return {
        
          count: 0,
          name: "张三"
        }
      },
      actions: {
        
        //把actions方法当作一个普通的方法即可,this指向的是当前store。
        changeCount(count) {
        
          this.count = count;
        },
        changeName(name) {
        
          this.name = name;
        }
      },
    })

/src/App.vue
    
    <template>
      <div>
        {
        {
         count }}
        <br />
        <n-button type="primary" @click="changeCount"> 修改count </n-button>
        <br />
        {
        {
         name }}
        <br />
        <n-button type="primary" @click="changeName"> 修改name </n-button>
      </div>
    </template>
    
    <script setup lang="ts">
    import {
         useStore } from "../stores/index";
    const state = useStore();
    import {
         storeToRefs } from "pinia";
    const {
         count,name } = storeToRefs(state);
    const changeCount = () => {
        
      state.changeCount(666);
    };
    const changeName = () => {
        
      state.changeName("李四");
    };
    </script>

## 5.持久化存储 ##

使用pinia-plugin-persistedstate实现持久化存储。  
[pinia-plugin-persistedstate][]

#### 5.1安装 ####

npm i pinia-plugin-persistedstate
    # 或者使用 yarn
    yarn add pinia-plugin-persistedstate
    # 或者使用 pnpm
    pnpm i pinia-plugin-persistedstate

#### 5.2添加实例 ####

// main.js
    
    import {
         createApp } from 'vue'
    import {
         createPinia } from 'pinia'
    import piniaPluginPersistedstate from 'pinia-plugin-persistedstate'
    import App from './App.vue'
    
    const pinia = createPinia()
    const app = createApp(App)
    app.use(pinia)
    pinia.use(piniaPluginPersistedstate)
    app.use(naive)
    app.use(router)
    app.mount('#app')

/src/store/index.js
    
    import {
         defineStore } from 'pinia'
    export const useStore = defineStore('main', {
        
      state: () => {
        
        return {
        
          count: 0,
          name: "张三",
          save:[
            {
         id: '1', name: '李四' },
            {
         id: '2', name: '王五' },
            {
         id: '3', name: '赵六' }
          ]
        }
      },
      actions: {
        
        changeCount(count) {
        
          this.count = count;
        },
        changeName(name) {
        
          this.name = name;
        }
      },
      persist: {
        
        key:"test",//唯一密钥
        paths: ["count","save.[]"],//部分持久状态、持久化整个状态
        storage: localStorage,//sessionStorage、localStorage
      },
    })

[pinia]: https://pinia.web3doc.top/
[pinia-plugin-persistedstate]: https://prazdevs.github.io/pinia-plugin-persistedstate/