角度编译失败答案

【问题标题】：Angular compilation fails角度编译失败
【发布时间】：2018-10-02 08:33:36
【问题描述】：

我正在关注 Angular 大学的一些视频教程。当我运行 ng serve/npm start 时，它会失败，但如果我只是通过添加/删除空白重新保存任何文件，它会成功编译。请找到以下截图：

My Package.json:

{
  "name": "reactive-patterns-course",
  "version": "0.0.0",
  "license": "MIT",
  "angular-cli": {},
  "scripts": {
    "ng": "ng",
    "start": "./node_modules/.bin/ng serve  --proxy-config proxy.conf.json",
    "rest-api": "./node_modules/.bin/ts-node ./src/server/server.ts",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "^5.0.0",
    "@angular/common": "^5.0.0",
    "@angular/compiler": "^5.0.0",
    "@angular/core": "^5.0.0",
    "@angular/forms": "^5.0.0",
    "@angular/http": "^5.0.0",
    "@angular/platform-browser": "^5.0.0",
    "@angular/platform-browser-dynamic": "^5.0.0",
    "@angular/router": "^5.0.0",
    "core-js": "^2.4.1",
    "rxjs": "^5.5.2",
    "zone.js": "^0.8.14",
    "@types/express": "^4.0.35",
    "@types/lodash": "^4.14.52",
    "angularfire2": "^4.0.0-rc.0",
    "firebase": "^3.7.4",
    "body-parser": "^1.17.1",
    "cookies-js": "^1.2.3",
    "express": "^4.15.2",
    "lodash": "^4.17.4",
    "promise-polyfill": "^6.0.2",
    "ts-helpers": "^1.1.1"
  },
  "devDependencies": {
    "@angular/cli": "1.5.0",
    "@angular/compiler-cli": "^5.0.0",
    "@angular/language-service": "^5.0.0",
    "@types/jasmine": "~2.5.53",
    "@types/jasminewd2": "~2.0.2",
    "@types/node": "~6.0.60",
    "codelyzer": "~3.2.0",
    "jasmine-core": "~2.6.2",
    "jasmine-spec-reporter": "~4.1.0",
    "karma": "~1.7.0",
    "karma-chrome-launcher": "~2.1.1",
    "karma-cli": "~1.0.1",
    "karma-coverage-istanbul-reporter": "^1.2.1",
    "karma-jasmine": "~1.1.0",
    "karma-jasmine-html-reporter": "^0.2.2",
    "protractor": "~5.1.2",
    "ts-node": "~3.2.0",
    "tslint": "~5.7.0",

        "typescript": "~2.4.2"
      }
    }

Could someone help me on this.I did run NPM update but of no avail.I have Angular CLI: 1.7.4
Node: 8.10.0

我在这里没有使用任何通用类型。即使有人使用它，它也应该一直失败。请在下面找到 app-data 文件。

import * as _ from 'lodash';
import {Observable} from 'rxjs/Observable';
import {Lesson} from '../shared/model/lesson';


export interface Observer {
    next(data: any);
}

export interface Observable {
  subscribe(obs: Observer);
  unsubscribe(obs: Observer);
}

interface Subject extends Observer, Observable {
}

    class  SubjectImplementation implements Subject {

      private observers: Observer[] = [];

      next(data: any) {
        this.observers.forEach(obs => obs.next(data));
      }

      subscribe(obs: Observer) {
        this.observers.push(obs);
      }

      unsubscribe(obs: Observer) {
        _.remove(this.observers, el => el === obs);
      }
    }

    const lessonsListSubject=new SubjectImplementation();

    export let lessonList$: Observable = {
      subscribe: obs => lessonsListSubject.subscribe(obs),
      unsubscribe: obs => lessonsListSubject.unsubscribe(obs)

    };

    let lessons: Lesson[] = [];

    export function initializeLessonsList(newList: Lesson[]) {
      lessons = _.cloneDeep(newList);
      lessonsListSubject.next(lessons);
    }

【问题讨论】：

看起来您正在使用 Observable<T> 类型，但没有指定泛型的类型。您能否提供您的 app-data.ts 文件，以便我们帮助您解决这些问题？
确保将其添加到我的问题详细信息中。
你为什么要尝试实现 rxjs 库提供的所有这些东西？是的，当你使用 rxjs observable 时，你需要在其上指定泛型参数。
我想先理解这个模式，因为我是菜鸟，后来我打算使用 RxJx，因为它可以帮助我更好地理解库/实用程序。非常感谢丹尼尔。

标签： angular typescript npm webpack angular-cli

【解决方案1】：

这个错误是非常不言自明的（甚至显示了错误所在的文件和行号 - app-data.ts(15,37)） - Observable 是一个泛型类型，需要一个类型。所以你不能在没有 Observable 的类型的情况下将某人的类型设置为 Observable。所以这是无效 - someVar: Observable。

在您的代码中，将 export let lessonList$: Observable = { 替换为 export let lessonList$: Observable<any> = { 或此 Observable 将流式传输的特定类型。

【讨论】：