在Angular 2项目中运行ng serve -aot命令时出错

Question

当我使用以下命令运行我的Angular 2项目时，我遇到一个错误：

ng serve -aot

堆栈跟踪：

ERROR in ./src/app/app.module.ngfactory.ts
Module build failed: Error: /Users/iguissouma/IdeaProjects/myproject/frontend/src/app/shared/services/message.service.ts (9,5): Public property 'messageSource$' of exported class has or is using name 'Observable' from external module "/Users/iguissouma/IdeaProjects/myproject/frontend/node_modules/rxjs/Observable" but cannot be named.)
    at _transpile (/Users/iguissouma/IdeaProjects/myproject/frontend/node_modules/@ngtools/webpack/src/loader.js:101:19)
    at /Users/iguissouma/IdeaProjects/myproject/frontend/node_modules/@ngtools/webpack/src/loader.js:128:26
    at tryCatch (/Users/iguissouma/IdeaProjects/myproject/frontend/node_modules/es6-promise/dist/lib/es6-promise/-internal.js:195:12)
    at invokeCallback (/Users/iguissouma/IdeaProjects/myproject/frontend/node_modules/es6-promise/dist/lib/es6-promise/-internal.js:210:13)
    at publish (/Users/iguissouma/IdeaProjects/myproject/frontend/node_modules/es6-promise/dist/lib/es6-promise/-internal.js:178:7)
    at flush (/Users/iguissouma/IdeaProjects/myproject/frontend/node_modules/es6-promise/dist/lib/es6-promise/asap.js:94:5)
    at nextTickCallbackWith0Args (node.js:420:9)
    at process._tickCallback (node.js:349:13)
 @ ./src/main.ts 4:0-64
 @ multi main

这个应用程序在ng serve上运行良好

如何解决这个问题？

message.service.ts

import { Injectable } from '@angular/core'
import { Subject } from 'rxjs/Subject';
import { Message } from 'primeng/primeng';

@Injectable()
export class MessageService {
    messageSource = new Subject<Message>();

    messageSource$ = this.messageSource.asObservable();

    info(summary : string, detail : string) {
        this.messageSource.next({severity:'info', summary: summary, detail: detail});
        console.log("INFO: " + summary + " DETAIL: " + detail);
    }

    error(summary : string, detail : string) {
        this.messageSource.next({severity:'error', summary: summary, detail: detail});
        console.log("ERROR: " + summary + " DETAIL: " + detail);
    }
}

Answer 1

我修改了message.service.ts，如下所示，为字段声明显式类型：

import { Injectable } from '@angular/core'
import { Subject } from 'rxjs/Subject';
import { Message } from 'primeng/primeng';
import { Observable } from 'rxjs/Rx';

@Injectable()
export class MessageService {
    messageSource:Subject<Message> = new Subject<Message>();

    messageSource$:Observable<Message> = this.messageSource.asObservable();

    info(summary : string, detail : string) {
        this.messageSource.next({severity:'info', summary: summary, detail: detail});
        console.log("INFO: " + summary + " DETAIL: " + detail);
    }

    error(summary : string, detail : string) {
        this.messageSource.next({severity:'error', summary: summary, detail: detail});
        console.log("ERROR: " + summary + " DETAIL: " + detail);
    }
}