RichText内容区域设置了<meta name="viewport" content="width=device-width">

@Component 
export struct SearchUnitRichTextComponent { 
 
  text: string = "" 
  fontSize:number = 16 
  fontColor:string = "#FFFFFF" 
  lineHeight:number = 25 
  maxLines:number = 1 
 
  build() { 
    RichText(`<meta name="viewport" content="width=device-width"><p style='display: -webkit-box;-webkit-box-orient: vertical;-webkit-line-clamp: 2; overflow: hidden; line-height: ${vp2px(this.lineHeight)}px; max-height: ${this.maxLines*(vp2px(this.lineHeight))}px; text-overflow: ellipsis; color:${this.fontColor}; text-align:start; font-size: ${vp2px(this.fontSize)}px;'>${enableHtmlEmToRed(this.text)}</p>`) 
      .width('100%') 
      .height(this.maxLines * this.lineHeight) 
  } 
} 
enableHtmlEmToRed(text:string) { 
  return text.replace(/<em>/g, '<em style="color: red;padding: 2px 4px;">'); 
}