在p对话框中p-footer不是已知的元素错误

Question

  

以html

<p-dialog [resizable]="false" header="Softcopy Acceptance for Ledger and 
Invoice" [(visible)]="!displaySoftCopyDialog"
[responsive]="true" showEffect="fade" [modal]="true" [width]="600">

<p style="margin: 5px; height: 305px"><span>
<span style="color:red;">GO GREEN</span><br>
Season’s Greetings! <br>
copy, they may consciously opt for the Hardcopy option.<br><br>
We wish for your consent to join us in this drive by opting for monthly 
bills through E-bill only.
</span></p>
<p-footer>
<div class="ui-dialog-buttonpane ui-widget-content ui-helper-clearfix">
    <button type="submit" class="btn btn_searchSmall_add" 
(click)="remindSoftCopy()">Remind Later</button>
    <button type="submit" class="btn btn_searchSmall_add" 
(click)="acceptSoftCopy()">Accept</button>
</div>
 </p-footer>
</p-dialog>

  

在ts文件中，我从primeng设置了这两个

DialogModule,
SharedModule

  

在模块中，我也从primeng设置了这两个

DialogModule,
SharedModule

  

为什么会这样

Answer 1

在package.json文件中使用的是什么版本的Prime NG？较早的库（1. 。）不支持p-footer和p-header，自版本2起已包含。