我的事件发射器没有发射。我已经用谷歌搜索了这个问题,看来我的代码顺序是错误的,或者至少这是我的猜测。无论我如何安排创建
Client
类的顺序,它都不会触发。
我正在创建一个通过 TCP/IP 与服务器通信的电子应用程序。当客户端连接状态发生变化时,应触发“连接”事件以告诉前端发生变化。其他事件(例如“错误”)正在运行。
客户端.js
class Client extends events.EventEmitter {
constructor(HOST, PORT){
// setting up the client..
super();
this.host = HOST;
this.port = PORT;
// and so on...
this.client = new net.Socket();
// othere eventlisteres...
this.client.on("connect", this.connectEventHandler);
}
connectEventHandler() {
try {
this.status = "connected"; // I can check the status from main
this.tryReconnecting = false; // other logic of the client class
this.emit("connection"); // this is the event (not working)
console.log("connection status should be triggered"); // this console.log is working
} catch (error) {
console.log(error);
this.emit("error", error);
}
}
}
main.js
// creating the client
const client = new Client(process.env.SERVER, process.env.PORT);
// when the app is ready, client is told to connect to the server
app.whenReady().then(() => {
createWindow();
app.on("activate", function () {
if (BrowserWindow.getAllWindows().length === 0) createWindow();
});
client.connect();
});
// the error event is working perfectly, event when I call it in the connectEventHandler
client.on("error", (message) => {
console.log("error event triggered");
dialog.showMessageBoxSync(mainWindow, {
title: "Fehler",
message: message,
});
});
// this part is not working
client.on("connection", () => {
console.log("new client status: " + client.status);
mainWindow.webContents.send("client-status", client.status);
});
即使我调用错误事件而不是连接事件,错误也会显示在我的应用程序中:
// code from client.js
connectEventHandler() {
try {
this.status = "connected"; // I can check the status from main
this.tryReconnecting = false; // other logic of the client class
// this part is getting ignored
this.emit("connection");
// this part is executed
this.emit("error", "this is a test error");
} catch (error) {
console.log(error);
this.emit("error", error);
}
}
最后一段代码(connectEventHandler)的响应:
这是怎么回事?
问题是 ConnectEventHandler,将该函数的逻辑放入客户端的构造函数后,每个事件都可以正确触发。