vue计算属性之：computed属性中的get与set用法

r囧r小猫 2024-04-18 18:42 61阅读 0赞

set：设置值时触发。

get：获取值时触发，与set是没有必然联系的。

<html>
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=gb2312" />
    <title>无标题文档</title>
    <script src="https://unpkg.com/vue/dist/vue.js"></script>
    </head>
     
    <body>
        <div id="div"> 
            <input v-model="changeFirstNameFn">
            <input v-model="changeSecondNameFn">
        <br />
        全名：<input id="full" v-model="fullName">
    </div>
     
    <body>
    <script src="https://cdn.jsdelivr.net/npm/vue/dist/vue.js"></script>
     
    <script> 
    var a=new Vue({
    el:"#div",               
    data:{ 
    	firstName:"",
    	lastName:"",
    	fullName:""
    }, 
    computed:{
    	changeFirstNameFn:{
    		get:function(){      // get 函数，返回绑定的“姓” 的输入框的value 值
    			return this.firstName
    		},
    		set:function(newVal){ //set函数是当数据发生变化时调用.监听到 “姓”的变化，执行set 函数
    			this.firstName=newVal
    			this.fullName=newVal+" "+ this.lastName
    		}
    	},	
    	changeSecondNameFn:{
    		get:function(){
    			return this.lastName},
    		set:function(newVal){   //set 函数是当数据发生变化时调用
    			this.lastName=newVal
    			this.fullName=this.firstName+" "+newVal
    			}
    		}
    	}
    })
     
    </script>
    </html>

tab标签页的用法

<template>
      <div id="main-container" class="main-container" :class="$store.state.app.collapse?'position-collapse-left':'position-left'">
        
        <div class="tab-container">
          <el-tabs class="tabs" :class="$store.state.app.collapse?'position-collapse-left':'position-left'"
            v-model="mainTabsActiveName" :closable="true" type="card"
            @tab-click="selectedTabHandle" @tab-remove="removeTabHandle">
            <el-dropdown class="tabs-tools" :show-timeout="0" trigger="hover">
              <div style="font-size:20px;width:50px;"><i class="el-icon-arrow-down"></i></div>
              <el-dropdown-menu slot="dropdown">
                <el-dropdown-item @click.native="tabsCloseCurrentHandle">关闭当前标签</el-dropdown-item>
                <el-dropdown-item @click.native="tabsCloseOtherHandle">关闭其它标签</el-dropdown-item>
                <el-dropdown-item @click.native="tabsCloseAllHandle">关闭全部标签</el-dropdown-item>
                <el-dropdown-item @click.native="tabsRefreshCurrentHandle">刷新当前标签</el-dropdown-item>
              </el-dropdown-menu>
            </el-dropdown>
            <el-tab-pane v-for="item in mainTabs"
              :key="item.name" :label="item.title" :name="item.name">
              <span slot="label"><i :class="item.icon"></i> {
       {item.title}} </span>
            </el-tab-pane>
          </el-tabs>
        </div>
        
        <div class="main-content">
          <keep-alive>
            <transition name="fade" mode="out-in">
                <router-view></router-view>
            </transition>
          </keep-alive>
        </div>
      </div>
    </template>
    
    <script>
    export default {
      data () {
        return {
        }
      },
      computed: {
        mainTabs: {
          get () { return this.$store.state.tab.mainTabs },
          set (val) { this.$store.commit('updateMainTabs', val) }
        },
        mainTabsActiveName: {
          get () { return this.$store.state.tab.mainTabsActiveName },
          set (val) { this.$store.commit('updateMainTabsActiveName', val) }
        }
      },
      methods: {
        // tabs, 选中tab
        selectedTabHandle (tab) {
          tab = this.mainTabs.filter(item => item.name === tab.name)
          if (tab.length >= 1) {
            this.$router.push({ name: tab[0].name })
          }
        },
        // tabs, 删除tab
        removeTabHandle (tabName) {
          this.mainTabs = this.mainTabs.filter(item => item.name !== tabName)
          if (this.mainTabs.length >= 1) {
            // 当前选中tab被删除
            if (tabName === this.mainTabsActiveName) {
              this.$router.push({ name: this.mainTabs[this.mainTabs.length - 1].name }, () => {
                this.mainTabsActiveName = this.$route.name
              })
            }
          } else {
            this.$router.push("/")
          }
        },
        // tabs, 关闭当前
        tabsCloseCurrentHandle () {
          this.removeTabHandle(this.mainTabsActiveName)
        },
        // tabs, 关闭其它
        tabsCloseOtherHandle () {
          this.mainTabs = this.mainTabs.filter(item => item.name === this.mainTabsActiveName)
        },
        // tabs, 关闭全部
        tabsCloseAllHandle () {
          this.mainTabs = []
          this.$router.push("/")
        },
        // tabs, 刷新当前
        tabsRefreshCurrentHandle () {
          var tempTabName = this.mainTabsActiveName
          this.removeTabHandle(tempTabName)
          this.$nextTick(() => {
            this.$router.push({ name: tempTabName })
          })
        }
      }
    }
    </script>
    
    <style scoped lang="scss">
    .main-container {
      padding: 0 5px 5px;
      position: absolute;
      top: 60px;
      left: 1px;
      right: 1px;
      bottom: 0px;
      // background: rgba(56, 5, 114, 0.5);
      .tabs {
        position: fixed;
        top: 60px;
        right: 50px;
        padding-left: 0px;
        padding-right: 2px;
        z-index: 1020;
        height: 40px;
        line-height: 40px;
        font-size: 14px;
        background: rgb(255, 253, 255);
        border-color: rgba(200, 206, 206, 0.5);
        // border-left-width: 1px;
        // border-left-style: solid;
        border-bottom-width: 1px;
        border-bottom-style: solid;
      }
     .tabs-tools {
        position: fixed;
        top: 60px;
        right: 0;
        z-index: 1020;
        height: 40px;
        // padding: 0 10px;
        font-size: 14px;
        line-height: 40px;
        cursor: pointer;
        border-color: rgba(200, 206, 206, 0.5);
        border-left-width: 1px;
        border-left-style: solid;
        border-bottom-width: 1px;
        border-bottom-style: solid;
        background: rgba(255, 255, 255, 1);
      }
      .tabs-tools:hover {
        background: rgba(200, 206, 206, 1);
      }
      .main-content {
        position: absolute;
        top: 45px;
        left: 5px;
        right: 5px;
        bottom: 5px;
        padding: 5px;
        // background: rgba(209, 212, 212, 0.5);
      }
    }
    .position-left {
      left: 200px;
    }
    .position-collapse-left {
      left: 65px;
    }
    </style>