VoiceOver无法在对话框中阅读内容

Question

对于我的Angular2网络应用程序，当我启动MdDialog时，iPhone的VoiceOver屏幕阅读器不会关注对话框并阅读标题。相反，它继续阅读对话框背后的内容。屏幕重点关注对话框关闭按钮。

<md-dialog-content>
  <div role="dialog" aria-labelledby="title" aria-describedby="consent-modal-content">
    <button class="dialog__close icon-close" type="button" md-dialog-close>Close</button>
    <div class="dialog__items">

      <div class="dialog__item">
        <h2 class='dialog__title' id="title">{{ title }}</h2>
      </div>

      <div class="dialog__item dialog__item--content">
        <span *ngIf="isLoading">Loading</span>
        <iframe *ngIf="content"
                id="consent-modal-content"
                oaoSrcdoc [content]="content"
                src="about:blank"
                frameborder="0"
                class="dialog__frame"></iframe>
      </div>
    </div>
  </div>
</md-dialog-content>