sockjs与typescript结合使用时，onclose、onopen和onerror无法正常工作。

1.为SockJSClient添加类型定义文件：

// sockjs-client.d.ts

declare class SockJSClient { constructor(url: string, options?: any);

onopen?: () => void;
onmessage?: (evt: any) => void;
onclose?: (event: CloseEvent) => void;
onerror?: (error: any) => void;

close(): void;
send(data: any): void;

}

2.在代码中对SockJSClient进行类型注解：

import * as SockJS from "sockjs-client";

const socket = new SockJS("http://localhost:8080/chat");

socket.onopen = () => { console.log("Socket connected!"); };

socket.onmessage = (event) => { console.log("Received message:", event.data); };

socket.onclose = (event) => { console.log(Socket disconnected: ${event.code} ${event.reason}); };

socket.onerror = (error) => { console.error("Error:", error); };

3.使用addEventListener和removeEventListener代替onclose、onopen和onerror：

import * as SockJS from "sockjs-client";

const socket = new SockJS("http://localhost:8080/chat");

socket.addEventListener("open", () => { console.log("Socket connected!"); });

socket.addEventListener("message", (event) => { console.log("Received message:", event.data); });

socket.addEventListener("close", (event) => { console.log(Socket disconnected: ${event.code} ${event.reason}); });

socket.addEventListener("error", (error) => { console.error("Error:", error); });

// To remove an event listener, use removeEventListener: const onOpen = () => { console.log("Socket connected!"); }; socket.addEventListener("open", onOpen); socket.removeEventListener("open", onOpen);