naive-ui/demo/documentation/components/checkbox/enUS/indeterminate.demo.md

Indeterminate

<n-checkbox v-model:value="value" :indeterminate="indeterminate">checkbox</n-checkbox>
<n-checkbox v-model:value="value" :indeterminate="indeterminate"/>
<n-checkbox v-model:value="value" :indeterminate="indeterminate" disabled/>
<n-button @click="value = !value" size="small">Check</n-button>
<n-button @click="indeterminate = !indeterminate" size="small">Indeterminate</n-button>

export default {
  data () {
    return {
      value: false,
      indeterminate: false
    }
  }
}

.n-checkbox, .n-button {
  margin: 0 12px 8px 0;
}