javascript - 您可能需要一个合适的加载器来处理这种文件类型。 Angular4-Firebase 表达式预期错误

Question

ERROR in C:/projects/chat/src/app/services/chat.service.ts (32,10): Expression expected.

ERROR in C:/projects/chat/src/app/services/chat.service.ts (32,10): Expression expected.

ERROR in ./src/app/services/chat.service.ts
Module parse failed: C:\projects\chat\node_modules\@ngtools\webpack\src\index.js!C:\projects\chat\src\app\services\chat.service.ts Unexpected token (24:15)
You may need an appropriate loader to handle this file type.
|     }
|     ChatService.prototype.getMessages = function () {
|         return .this.db.list('messages', {
|             query: {
|                 limitToLast: 25,
 @ ./src/app/app.module.ts 25:0-54
 @ ./src/main.ts
 @ multi webpack-dev-server/client?http://localhost:4200 ./src/main.ts

聊天服务

import { Injectable } from '@angular/core';
import {AngularFireDatabase,FirebaseListObservable} from 'angularfire2/database';
import {AngularFireAuth} from 'angularfire2/auth';
import {Observable} from 'rxjs/Observable';
import {ChatMessage} from '../models/chat-message.model';
import {AuthService} from '../services/auth.service';
import * as firebase from'firebase/app';




@Injectable()
export class ChatService {

user: any;
chatMessages: FirebaseListObservable<ChatMessage[]>;
chatMessage: ChatMessage;
userName: Observable<string>;


  constructor(private db: AngularFireDatabase,private afAuth: AngularFireAuth) {

//this.afAuth.authState.subscribe(auth=>{
  //if(auth !== undefined && auth !==null){
    //this.user = auth;
  //}
//});
   }


   getMessages(): FirebaseListObservable<ChatMessage[]>{
   return.this.db.list('messages',{
   query: {
   limitToLast:25,
   orderByKey: true
   }
   });
   }

   getTimeStamp(){
 const now = new Date();
 const date = now.getUTCFullYear() + '/' +
 (now.getUTCMonth() +1) + '/' +
 now.getUTCDate();
 const time = now.getUTCHours() + ':' +
 now.getUTCMinutes()  + ':' +
 now.getUTCSeconds();

 return ( date+' '+time);

   }



  sendMessage(msg: string){
const timestamp = this.getTimeStamp();
//const email = this.user.email;
const email = "test@example.com";
this.chatMessages = this.getMessages();
this.chatMessages.push({
message: msg,
timeSent: timestamp,
//userName: this.userName,
userName: "testuser",
email: email
});
  }

}

我正在关注 YouTube 上的一个教程，内容是关于构建一个以 angular 4 作为前端和 Firebase 作为后端的聊天应用程序，我遵循了所有内容，但仍然出现此错误。有任何想法吗？我很确定我已经安装了所有依赖项。

Answer 1

这个声明:

return.this.db.list('messages',{

应该是这样的:

return this.db.list('messages',{

额外的句点是语法错误。根据您使用的 IDE，这应该在编译之前作为错误显示给您。

祝你好运!