最近我也做了类似的事情：

组件.hbs：

{{#each this.choices as |item|}}
  {{input
    type="text"
    id=item.id
    keyPress=(action this.newElement item)
    value=(mut item.value)
  }}
{{/each}}

组件.js

@action
newElement({ id }) {
  let someEmpty = this.choices.some(({ value }) => isBlank(value));

  if (!someEmpty)
    this.choices = [...this.choices, this.generateOption()];

  document.getElementById(id).focus();
}

generateOption(option) {
  this.inc ++;

  if (!option)
    option = this.store.createRecord('option');

  return {
    option,
    id: `${this.elementId}-${this.inc}`,
    value: option.description
  };
}

在我的例子中，我没有按钮，我已经创建了ember数据记录。通过一些修改，我打赌你可以做到这一点！

发现我可以在组件重新呈现后使用Ember.run.schedule来运行代码。

@action
addWhy() {
    ... // Adding why field
    Ember.run.schedule('afterRender', () => {
      // When this function has called, the component has already been re-rendered
      let fiveWhyInput = document.querySelector(`#five-why-${index}`) as HTMLTextAreaElement
      if (fiveWhyInput)
        fiveWhyInput.focus();
    })
}