显示<；apex:pageMessages>；在javascript中

如何在javascript中显示apex:pageMessages？这是我在vf页面中的代码

<apex:form id="frm">
                            <apex:pageBlock id="pb1">
                            <div style="position: absolute; left: 100px; top: 50px;">
                            <apex:pageMessages id="showmsg"></apex:pageMessages>
                            </div>
       </apex:form>

您可以创建一个and控制器方法来添加错误消息并重新发送页面消息

页面：

<apex:pageBlock id="messages">
    <apex:pageMessages id="showmsg" />
</apex:pageBlock>

<apex:actionFunction name="showPageMessage" action="{!showPageMessage}" rerender="messages">
  <apex:param name="level" assignTo="{!level}" value="" />
  <apex:param name="message" assignTo="{!message}" value="" />
</apex:actionFunction>
<!--...-->
<script>
  showMessage('WARNING', 'Here is the page message');
<script>

//...
public String level {get; set;}
public String message {get; set;}

public void showPageMessage() {
  if(level == 'WARNING') {
    ApexPages.addMessage(new ApexPages.Message(ApexPages.Severity.Warning, message));
  }
}