Vue2 中 ref 用法示例

原创已于 2022-04-16 21:49:53 修改 · 1.2k 阅读

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#vue.js #前端 #js

于 2022-04-16 21:43:55 首次发布

本文详细介绍了Vue.js中组件之间的通信方法，包括使用`$refs`获取子组件实例、父组件获取子组件数据、父组件调用子组件方法以及子组件如何触发父组件方法。同时，通过实例展示了如何避免直接操作DOM，利用Vue的响应式系统进行数据交互，提升应用性能。

文章目录

一般情况下需要获取dom元素中的值需要如下代码处理：

<!DOCTYPE html>
<html>
  
  <head>
    <meta charset="utf-8">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <title></title>
    
    <script type="text/javascript">
      function getUser() {
        let data = document.querySelector(".user").value;
        alert(data);
      }
      
      function getPwd() {
        let data = document.getElementById("pwd").value;
        alert(data);
      }
    </script>
  </head>
  
  <body>
    <input class="user" type="text" name="username">
    <input id="pwd" type="text" name="password">
    <button onclick="getUser()">获取User</button>
    <button onclick="getPwd()">获取Pwd</button>
  </body>
  
</html>

1、基本用法

<template>
<div>
  <div ref="basicRef">hello world</div>
  <button @click="getDom">点击获取</button>
  </div>
</template>

<script>
  export default {
    methods: {
      getDom() {
        console.log(this.$refs.basicRef);
      },
    },
  };
</script>

点击输出：<div>hello world</div>

2、父组件获取子组件数据

<template>
  <div>
    {{msg}}
  </div>
</template>

<script>
export default {
  data() {
    return {
      msg: "child component",
    };
  },
};
</script>

<template>
  <div>
    <ChildRefSample ref="childRef" />
    <button @click="getChildData">获取子组件数据</button>
  </div>
</template>

<script>
import ChildRefSample from "./ChildRefSample.vue";
export default {
  components: {
    ChildRefSample,
  },
  methods: {
    getChildData() {
      console.log("getChildData: ", this.$refs.childRef.msg);
    },
  },
};
</script>

点击输出：getChildData: child component

3、父组件调用子组件方法

<template>
  <div>
  </div>
</template>

<script>
export default {
  methods: {
    hello() {
      console.log("hello");
    },
  },
};
</script>

<template>
  <div>
    <ChildRefSample ref="childRef" />
    <button @click="getChildData">获取子组件数据</button>
  </div>
</template>

<script>
import ChildRefSample from "./ChildRefSample.vue";
export default {
  components: {
    ChildRefSample,
  },
  methods: {
    getChildData() {
      this.$refs.childRef.hello()
    },
  },
};
</script>

输出：hello

4、子组件调用父组件方法

<template>
  <div></div>
</template>
<script>
export default {
  methods: {
    hello() {
      this.$emit("callParent");
    },
  },
};
</script>

<template>
  <div>
    <ChildRefSample
      ref="childRef"
      @callParent="printData"
    />
    <button @click="getChildData">获取子组件数据</button>
  </div>
</template>

<script>
import ChildRefSample from "./ChildRefSample.vue";
export default {
  components: {
    ChildRefSample,
  },
  methods: {
    getChildData() {
      this.$refs.childRef.hello();
    },
    printData() {
      console.log("print parent data");
    },
  },
};
</script>

输出：print parent data

PS：最新在学前端，以下是学习过程中写的一个小程序，欢迎体验～