vue3 setup怎么拿this

在Vue3中，setup函数是一个新的组件选项，它是在beforeCreate和created之前执行的。在setup函数中，this指向的是undefined，因为在Vue3中，this已经不再是组件实例。如果你需要访问组件实例，可以使用Vue3提供的一个新的API：`getCurrentInstance()`。这个API可以获取到当前组件实例的引用，从而可以访问组件实例的属性和方法。例如：

import { getCurrentInstance } from 'vue'

export default {
  setup() {
    const instance = getCurrentInstance()
    console.log(instance.props) // 访问组件实例的props
    console.log(instance.emit) // 访问组件实例的emit方法
    // ...
  }
}

相关问题

Vue3 setup 怎么使用this.$refs

根据提供的引用内容，Vue3的setup中没有绑定this，因此无法使用this.$refs来获取节点。但是，我们可以使用以下两种方法来获取节点：

方法一：

<template>
  <p ref="myRef">hello</p>
</template>

<script>
import { ref, onMounted } from 'vue'

export default {
  setup() {
    const myRef = ref(null)

    onMounted(() => {
      console.log(myRef.value) // 输出： <p>hello</p>
    })

    return {
      myRef
    }
  }
}
</script>

方法二：

<template>
  <p ref="myRef">hello</p>
</template>

<script setup>
import { onMounted, getCurrentInstance } from 'vue'

const p = getCurrentInstance()
const { proxy } = getCurrentInstance()

onMounted(() => {
  console.log(p.refs.myRef) // 输出： <p>hello</p>
  console.log(proxy.$refs.myRef) // 输出： <p>hello</p>
})
</script>

vue3 setup

Vue 3 introduces a new function called `setup` to replace the options-based API used in Vue 2. The `setup` function allows you to initialize component state, define computed properties, and set up component lifecycle hooks.

In Vue 3, the `setup` function is executed before the component is created, providing a more explicit and flexible way to define component logic. Here's an example of how to use the `setup` function:

<template>
  <div>
    <p>{{ message }}</p>
    <button @click="increment">Increment</button>
  </div>
</template>

<script>
import { ref } from 'vue';

export default {
  setup() {
    const message = ref('Hello Vue 3');
    
    function increment() {
      message.value += '!';
    }

    return {
      message,
      increment
    };
  }
};
</script>

In the example above, we import `ref` from the `vue` package, which allows us to create a reactive reference. Inside the `setup` function, we declare a `message` variable using `ref`, and a function called `increment` that appends an exclamation mark to the message. We then return these variables and functions as an object from the `setup` function.

By using the `setup` function, you can access reactive properties and functions directly in the template without the need for the `this` context. This makes the code more concise and easier to read.

I hope this helps! Let me know if you have any further questions.