errors.ts:42 ERROR Error: Uncaught (in promise):

Question

我的聊天服务出现这个错误我无法解决
Here's the error

这是我的聊天服务的实际代码

import{Injectable} from '@angular/core';
import {Subject} from 'rxjs/Subject';
import {Observable} from 'rxjs/Observable';
 import * as io from 'socket.io-client';
export class chatService{
    private url = 'http://localhost:8000'
    private socket:any;

    sendMessage(message:string){
        this.socket.emit('add-message', message);
    }
    getMessages(){
        let observable = new Observable(( observer:any)=>{
            this.socket = io(this.url);
            this.socket.on('message',(data:any)=>{
                observer.next(data);
            });
            return () => {
                this.socket.disconnect();
            }
        })
        return observable;
    }

}

Answer 1

首先，根据 Angular Style Guide，您应该为您的服务使用大写字母（又名。chatService => ChatService）
接下来，您是否将 ChatService 作为提供程序包含在应用程序的模块文件中？
```
@NgModule({
    providers: [
        ChatService
    ]
})
```

errors.ts:42 ERROR Error: Uncaught (in promise):

errors.ts:42 ERROR Error: Uncaught (in promise):

angular-providers

angular