HarmonyOS EmitterData在接收端如何解析？

import emitter from '@ohos.events.emitter' 
 
function registerEvent() { // 定义一个eventId为1的事件  
  let event: emitter.InnerEvent = { eventId: 1 }; // 收到eventId为1的事件后执行该回调  
  let callback = (eventData: emitter.EventData) => { 
  let content: emitter.EventData = eventData["content"] 
  let id: emitter.EventData = eventData["id"] 
  let isEmpty: emitter.EventData = eventData["isEmpty"] 
  console.info('event callback content=' + content); 
  }; // 订阅eventId为1的事件  
  emitter.on(event, callback); 
} 
function sendEvent() { // 定义一个eventId为1的事件，事件优先级为 
Low let event: emitter.InnerEvent = { eventId: 1, priority: emitter.EventPriority.LOW };  
let data = new Map<string, Object>();  
data.set("content", "c");  
data.set("id", 1);  
data.set("isEmpty", false);  
let eventData: emitter.EventData = { data }; // 发送eventId为1的事件，事件内容为eventData emitter.emit(event, eventData); } @Entry  
@Component  
struct Index  
{  
@State message: string = 'Hello World' build() {  
Row() {  
Column() {  
Text("发送")  
.fontSize(50)  
.fontWeight(FontWeight.Bold)  
.onClick(()=> { sendEvent(); })  
Text("注册")  
.fontSize(50)  
.fontWeight(FontWeight.Bold)  
.onClick(()=> { registerEvent(); }) } 
.width('100%') 
} 
.height('100%') 
} 
}