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Uncaught TypeError: Cannot read properties of undefined (reading ‘value‘),为什么没实现出5来?

作者:hamimelon2020 更新时间: 2022-02-22 编程语言
<!DOCTYPE html>
<div id="v-model-example" class="demo">
  <todo-list></todo-list>
  <todo-list-statistics></todo-list-statistics>
    </div>

<script src="https://unpkg.com/vue@next"></script>
<script>
    const app = Vue.createApp({}); 
    app.component('todo-list', {
      data() {
        return {
          todos: ['Feed a cat', 'Buy milk']
        }
      },
      provide() {
        return {
          todoLength: Vue.computed(() => this.todos.length)
    }
  },
  template: `
   <div>{{ todos.length }}</div>
  `
    })

    app.component('todo-list-statistics', {
      inject: ['todoLength'],
      created() {
        console.log(`Injected property: ${this.todoLength.value}`) // > 注入的 property: 5
  }
  
}

).mount('#v-model-example')
</script>


<!DOCTYPE html>
<div id="v-model-example" class="demo">
  <todo-list></todo-list>
  <todo-list-statistics></todo-list-statistics>
    </div>

<script src="https://unpkg.com/vue@next"></script>
<script>
    const app = Vue.createApp({}); 
    app.component('todo-list', {
      data() {
        return {
          todos: ['Feed a cat', 'Buy milk', 'Drink water']
        }
      },
      provide() {
        return {
          todoLength: Vue.computed(() => this.todos.length)
    }
  },
  template: `
   <div>{{ todos.length }}</div>
  `
    })

    app.component('todo-list-statistics', {
      inject: ['todoLength'],
      created() {
        console.log(`Injected property: ${this.todoLength.value}`) // > 注入的 property: 5
  }
  
}

).mount('#v-model-example')
</script>


原文链接:https://blog.csdn.net/weixin_40945354/article/details/123166373

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