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In Vue, checkboxes are a very common interactive component that allows users to select multiple options. This article will introduce how to set up checkbox functionality in Vue and provide some practical examples.

Using the v-model directive

The directive in Vue v-modelcan implement two-way data binding, thereby synchronizing the checkbox selection state with the data model. For example, we can define a checkbox component like this:

<template>
  <div>
    <label>
      <input type="checkbox" v-model="checked" />
      {{ label }}
    </label>
  </div>
</template>

<script>
export default {
  props: {
    label: String,
    value: Boolean,
  },
  data() {
    return {
      checked: this.value,
    };
  },
  watch: {
    checked(newVal) {
      this.$emit("input", newVal);
    },
  },
};
</script>

In this component, we use v-modelthe directive to bind the checked property and initialize the value of checked in data . When the user clicks the checkbox, the value of checked is automatically updated, triggering watchthe callback function in and passing the latest value $emitto the parent component through the method.

When using this checkbox component, we can write it like this:

<template>
  <div>
    <checkbox v-model="checked" label="选项1" />
    <checkbox v-model="checked" label="选项2" />
    <checkbox v-model="checked" label="选项3" />
  </div>
</template>

<script>
import Checkbox from "./Checkbox.vue";

export default {
  components: {
    Checkbox,
  },
  data() {
    return {
      checked: [false, false, false],
    };
  },
};
</script>

In this parent component, we use three checkbox components and v-modelbind them to the same array checked . Each element in this array corresponds to a checkbox. When the user selects a checkbox, the corresponding element in the checked array is automatically updated.

Use v-bind to bind the checked attribute

In addition to using v-modelthe directive, we can also use v-bindthe directive to bind the checked attribute to synchronize the checkbox's selection state with the data model. For example, we can define a checkbox component like this:

<template>
  <div>
    <label>
      <input type="checkbox" v-bind:checked="checked" v-on:change="handleChange" />
      {{ label }}
    </label>
  </div>
</template>

<script>
export default {
  props: {
    label: String,
    value: Boolean,
  },
  data() {
    return {
      checked: this.value,
    };
  },
  methods: {
    handleChange(event) {
      this.checked = event.target.checked;
      this.$emit("input", this.checked);
    },
  },
};
</script>

In this component, we use v-bindthe directive to bind the checked property and initialize the checked value in data . When the user clicks the checkbox, the change event is triggered, which calls the method and passes the latest value to the parent component through the method.handleChange$emit

When using this checkbox component, we can write it like this:

<template>
  <div>
    <checkbox v-bind:checked="checked[0]" v-on:input="checked[0] = $event.target.checked" label="选项1" />
    <checkbox v-bind:checked="checked[1]" v-on:input="checked[1] = $event.target.checked" label="选项2" />
    <checkbox v-bind:checked="checked[2]" v-on:input="checked[2] = $event.target.checked" label="选项3" />
  </div>
</template>

<script>
import Checkbox from "./Checkbox.vue";

export default {
  components: {
    Checkbox,
  },
  data() {
    return {
      checked: [false, false, false],
    };
  },
};
</script>

In this parent component, we use three checkbox components and bind their checked properties to the corresponding elements of the checked array. When the user selects a checkbox, the corresponding checked array element is automatically updated.

Summarize

This article introduces two methods of setting the checkbox function in Vuev-model : using the directive and using v-bindthe directive. Regardless of which method is used, it is necessary to synchronize the selection state of the checkbox with the data model to ensure the correctness of the data. In actual development, we can choose different methods according to specific needs and demonstrate them with actual examples.