vue3限制table表格选项个数的解决方法

<div id="q-app" style="min-height: 100vh;">
  <div class="q-pa-md">
    <q-table
      title="Treats"
      :rows="rows"
      :columns="columns"
      row-key="name"
      :selected-rows-label="getSelectedString"
      selection="multiple"
      v-model:selected="selected"
    ></q-table>

    <div class="q-mt-md">
      Selected: {{ JSON.stringify(selected) }}
    </div>
  </div>
</div>

const { ref } = Vue

const columns = [
  {
    name: 'desc',
    required: true,
    label: 'Dessert (100g serving)',
    align: 'left',
    field: row => row.name,
    fORMat: val => `${val}`,
    sortable: true
  },
  { name: 'calories', align: 'center', label: 'Calories', field: 'calories', sortable: true },
  { name: 'fat', label: 'Fat (g)', field: 'fat', sortable: true },
  { name: 'carbs', label: 'Carbs (g)', field: 'carbs' },
  { name: 'protein', label: 'Protein (g)', field: 'protein' },
  { name: 'sodium', label: 'Sodium (mg)', field: 'sodium' },
  { name: 'calcium', label: 'Calcium (%)', field: 'calcium', sortable: true, sort: (a, b) => parseInt(a, 10) - parseInt(b, 10) },
  { name: 'iron', label: 'Iron (%)', field: 'iron', sortable: true, sort: (a, b) => parseInt(a, 10) - parseInt(b, 10) }
]

const rows = [
  {
    name: 'Frozen Yogurt',
    calories: 159,
    fat: 6.0,
    carbs: 24,
    protein: 4.0,
    sodium: 87,
    calcium: '14%',
    iron: '1%'
  },
  {
    name: 'Ice cream sandwich',
    calories: 237,
    fat: 9.0,
    carbs: 37,
    protein: 4.3,
    sodium: 129,
    calcium: '8%',
    iron: '1%'
  },
  {
    name: 'Eclair',
    calories: 262,
    fat: 16.0,
    carbs: 23,
    protein: 6.0,
    sodium: 337,
    calcium: '6%',
    iron: '7%'
  },
  {
    name: 'Cupcake',
    calories: 305,
    fat: 3.7,
    carbs: 67,
    protein: 4.3,
    sodium: 413,
    calcium: '3%',
    iron: '8%'
  },
  {
    name: 'Gingerbread',
    calories: 356,
    fat: 16.0,
    carbs: 49,
    protein: 3.9,
    sodium: 327,
    calcium: '7%',
    iron: '16%'
  },
  {
    name: 'Jelly bean',
    calories: 375,
    fat: 0.0,
    carbs: 94,
    protein: 0.0,
    sodium: 50,
    calcium: '0%',
    iron: '0%'
  },
  {
    name: 'Lollipop',
    calories: 392,
    fat: 0.2,
    carbs: 98,
    protein: 0,
    sodium: 38,
    calcium: '0%',
    iron: '2%'
  },
  {
    name: 'Honeycomb',
    calories: 408,
    fat: 3.2,
    carbs: 87,
    protein: 6.5,
    sodium: 562,
    calcium: '0%',
    iron: '45%'
  },
  {
    name: 'Donut',
    calories: 452,
    fat: 25.0,
    carbs: 51,
    protein: 4.9,
    sodium: 326,
    calcium: '2%',
    iron: '22%'
  },
  {
    name: 'KitKat',
    calories: 518,
    fat: 26.0,
    carbs: 65,
    protein: 7,
    sodium: 54,
    calcium: '12%',
    iron: '6%'
  }
]

const app = Vue.createApp({
  setup () {
    const selected = ref([])

    return {
      selected,
      columns,
      rows,

      getSelectedString () {
        if(selected.value.length > 2){
          **selected.value.length = 2**
          return 0
        } else {
          return selected.value.length === 0 ? '' : `${selected.value.length} record${selected.value.length > 1 ? 's' : ''} selected of ${rows.length}`
        }
        
      }
    }
  }
})

app.use(Quasar, { config: {} })
app.mount('#q-app')