根据我对您问题的理解，您希望为数组中的每个元素打开一个对话框，您可以做的是创建一个对话框元素，并使用属性显示使其可见

<h5>Basic</h5>
<ul *ngFor="let activity of duplicateList;let i=index;">
  <li>{{activity.label}} -- {{activity.present}}
  </li>
  <p-dialog id="id">
    <p-header>
      {{activity.label}}
    </p-header>

    <p-footer>
      <button type="button" pButton icon="pi pi-check" (click)="openDialog(activity)" label="Yes"></button>
      <button type="button" pButton icon="pi pi-close" (click)="closeDialog()" label="No" class="ui-button-secondary"></button>
    </p-footer>
  </p-dialog>
</ul>

<div *ngIf="display" class="dialog-box">
  {{content}}
</div>

在app.component.ts文件中，您可以添加opendialog和closedialog方法，如下所示

openDialog(activity: any){
      this.display = true;
      this.content = activity
  }
  closeDialog(){
    this.display = false;
  }