typescript - 属性不存在运行 Angular2 ver.2.0.0-alpha.44 的问题

Question

Angular2 的新手，试图获得 this plunkr在我的本地系统上运行的项目。我收到以下错误:

错误:(25, 23) TS2339:属性“people”在类型“PeopleService”上不存在。 错误:(26, 39) TS2339: 属性“people”在类型“People”中不存在

在线: peopleService.people
.subscribe(people => this.people = people);

我有理由相信我已经正确设置了环境，因为我有其他基本组件正在正常运行。

people.ts 文件:

import {Component, View, CORE_DIRECTIVES} from 'angular2/angular2'  
import {PeopleService} from './peopleService'  
import {Person} from './person'

@Component({  
    selector: 'my-app',  
    providers: [PeopleService]  
})  
@View({
    template: `
    <div>
      <h2>Hello Angular2!</h2>
      <my-person
        *ng-for="#person of people"
        [name]="person.name"
        (hello)="saidHello($event)">
      </my-person>
    </div>
  `,  
        directives: [CORE_DIRECTIVES, Person]  
})  
export class People {  
    constructor(public peopleService:PeopleService) {  
        peopleService.people  
            .subscribe(people => this.people = people);  
    }  
    saidHello($event){  
        alert(`You said hello to ${$event}`)  
    }
}

peopleService.ts 文件中的类似错误:

错误:(8, 14) TS2339:“PeopleService”类型上不存在属性“people”。

//a simple service
import {Injectable} from 'angular2/angular2';
import {Http} from 'angular2/http';

@Injectable()
export class PeopleService {
  constructor(http:Http) {
    this.people = http.get('api/people.json').map(res => res.json());
  }
}

任何指导将不胜感激!

Yaniv, I'm still working thru this, below is the exception after implementing the change.  Also, I didn't notice this before but I'm getting a warning in the people.ts file on the following statements:
    [name]="person.name"
    (hello)="saidHello($event)">

警告 此处不允许属性 [name]
此处不允许使用属性 (hello)

EXCEPTION: Cannot resolve all parameters for People(?). Make sure they all have valid type or annotations.
angular2.dev.js:21835 EXCEPTION: Cannot resolve all parameters for People(?). Make sure they all have valid type or annotations.BrowserDomAdapter.logError @ angular2.dev.js:21835BrowserDomAdapter.logGroup @ angular2.dev.js:21846ExceptionHandler.call @ angular2.dev.js:4431(anonymous function) @ angular2.dev.js:19543NgZone._onError @ angular2.dev.js:10711errorHandling.onError @ angular2.dev.js:10630run @ angular2.dev.js:141(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$$internal$$tryCatch @ angular2.dev.js:1507lib$es6$promise$$internal$$invokeCallback @ angular2.dev.js:1519lib$es6$promise$$internal$$publish @ angular2.dev.js:1490(anonymous function) @ angular2.dev.js:219microtask @ angular2.dev.js:10670run @ angular2.dev.js:138(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$asap$$flush @ angular2.dev.js:1301
angular2.dev.js:21835 STACKTRACE:BrowserDomAdapter.logError @ angular2.dev.js:21835ExceptionHandler.call @ angular2.dev.js:4433(anonymous function) @ angular2.dev.js:19543NgZone._onError @ angular2.dev.js:10711errorHandling.onError @ angular2.dev.js:10630run @ angular2.dev.js:141(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$$internal$$tryCatch @ angular2.dev.js:1507lib$es6$promise$$internal$$invokeCallback @ angular2.dev.js:1519lib$es6$promise$$internal$$publish @ angular2.dev.js:1490(anonymous function) @ angular2.dev.js:219microtask @ angular2.dev.js:10670run @ angular2.dev.js:138(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$asap$$flush @ angular2.dev.js:1301
angular2.dev.js:21835 Error: Cannot resolve all parameters for People(?). Make sure they all have valid type or annotations.
    at NoAnnotationError.BaseException [as constructor] (http://127.0.0.1:8080/node_modules/angular2/bundles/angular2.dev.js:16034:21)
    at new NoAnnotationError (http://127.0.0.1:8080/node_modules/angular2/bundles/angular2.dev.js:4983:14)
    at _dependenciesFor (http://127.0.0.1:8080/node_modules/angular2/bundles/angular2.dev.js:20066:13)
    at resolveFactory (http://127.0.0.1:8080/node_modules/angular2/bundles/angular2.dev.js:19964:22)
    at Object.resolveProvider (http://127.0.0.1:8080/node_modules/angular2/bundles/angular2.dev.js:19983:66)
    at Function.DirectiveProvider.createFromProvider (http://127.0.0.1:8080/node_modules/angular2/bundles/angular2.dev.js:23906:27)
    at Function.DirectiveProvider.createFromType (http://127.0.0.1:8080/node_modules/angular2/bundles/angular2.dev.js:23915:32)
    at provideDirective (http://127.0.0.1:8080/node_modules/angular2/bundles/angular2.dev.js:27209:49)
    at http://127.0.0.1:8080/node_modules/angular2/bundles/angular2.dev.js:27188:14
    at Array.map (native)BrowserDomAdapter.logError @ angular2.dev.js:21835ExceptionHandler.call @ angular2.dev.js:4434(anonymous function) @ angular2.dev.js:19543NgZone._onError @ angular2.dev.js:10711errorHandling.onError @ angular2.dev.js:10630run @ angular2.dev.js:141(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$$internal$$tryCatch @ angular2.dev.js:1507lib$es6$promise$$internal$$invokeCallback @ angular2.dev.js:1519lib$es6$promise$$internal$$publish @ angular2.dev.js:1490(anonymous function) @ angular2.dev.js:219microtask @ angular2.dev.js:10670run @ angular2.dev.js:138(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$asap$$flush @ angular2.dev.js:1301
angular2.dev.js:21845 EXCEPTION: TypeError: Cannot read property 'location' of undefined
angular2.dev.js:21835 EXCEPTION: TypeError: Cannot read property 'location' of undefinedBrowserDomAdapter.logError @ angular2.dev.js:21835BrowserDomAdapter.logGroup @ angular2.dev.js:21846ExceptionHandler.call @ angular2.dev.js:4431(anonymous function) @ angular2.dev.js:19543NgZone._onError @ angular2.dev.js:10711errorHandling.onError @ angular2.dev.js:10630run @ angular2.dev.js:141(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$$internal$$tryCatch @ angular2.dev.js:1507lib$es6$promise$$internal$$invokeCallback @ angular2.dev.js:1519lib$es6$promise$$internal$$publish @ angular2.dev.js:1490(anonymous function) @ angular2.dev.js:219microtask @ angular2.dev.js:10670run @ angular2.dev.js:138(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$asap$$flush @ angular2.dev.js:1301
angular2.dev.js:21835 STACKTRACE:BrowserDomAdapter.logError @ angular2.dev.js:21835ExceptionHandler.call @ angular2.dev.js:4433(anonymous function) @ angular2.dev.js:19543NgZone._onError @ angular2.dev.js:10711errorHandling.onError @ angular2.dev.js:10630run @ angular2.dev.js:141(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$$internal$$tryCatch @ angular2.dev.js:1507lib$es6$promise$$internal$$invokeCallback @ angular2.dev.js:1519lib$es6$promise$$internal$$publish @ angular2.dev.js:1490(anonymous function) @ angular2.dev.js:219microtask @ angular2.dev.js:10670run @ angular2.dev.js:138(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$asap$$flush @ angular2.dev.js:1301
angular2.dev.js:21835 TypeError: Cannot read property 'location' of undefined
    at angular2.dev.js:19434
    at Zone.run (angular2.dev.js:138)
    at Zone.run (angular2.dev.js:10644)
    at zoneBoundFn (angular2.dev.js:111)
    at lib$es6$promise$$internal$$tryCatch (angular2.dev.js:1507)
    at lib$es6$promise$$internal$$invokeCallback (angular2.dev.js:1519)
    at lib$es6$promise$$internal$$publish (angular2.dev.js:1490)
    at angular2.dev.js:219
    at microtask (angular2.dev.js:10670)
    at Zone.run (angular2.dev.js:138)BrowserDomAdapter.logError @ angular2.dev.js:21835ExceptionHandler.call @ angular2.dev.js:4434(anonymous function) @ angular2.dev.js:19543NgZone._onError @ angular2.dev.js:10711errorHandling.onError @ angular2.dev.js:10630run @ angular2.dev.js:141(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$$internal$$tryCatch @ angular2.dev.js:1507lib$es6$promise$$internal$$invokeCallback @ angular2.dev.js:1519lib$es6$promise$$internal$$publish @ angular2.dev.js:1490(anonymous function) @ angular2.dev.js:219microtask @ angular2.dev.js:10670run @ angular2.dev.js:138(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$asap$$flush @ angular2.dev.js:1301
angular2.dev.js:21845 EXCEPTION: TypeError: Cannot read property 'hostView' of undefined
angular2.dev.js:21835 EXCEPTION: TypeError: Cannot read property 'hostView' of undefinedBrowserDomAdapter.logError @ angular2.dev.js:21835BrowserDomAdapter.logGroup @ angular2.dev.js:21846ExceptionHandler.call @ angular2.dev.js:4431(anonymous function) @ angular2.dev.js:19543NgZone._onError @ angular2.dev.js:10711errorHandling.onError @ angular2.dev.js:10630run @ angular2.dev.js:141(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$$internal$$tryCatch @ angular2.dev.js:1507lib$es6$promise$$internal$$invokeCallback @ angular2.dev.js:1519lib$es6$promise$$internal$$publish @ angular2.dev.js:1490(anonymous function) @ angular2.dev.js:219microtask @ angular2.dev.js:10670run @ angular2.dev.js:138(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$asap$$flush @ angular2.dev.js:1301
angular2.dev.js:21835 STACKTRACE:BrowserDomAdapter.logError @ angular2.dev.js:21835ExceptionHandler.call @ angular2.dev.js:4433(anonymous function) @ angular2.dev.js:19543NgZone._onError @ angular2.dev.js:10711errorHandling.onError @ angular2.dev.js:10630run @ angular2.dev.js:141(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$$internal$$tryCatch @ angular2.dev.js:1507lib$es6$promise$$internal$$invokeCallback @ angular2.dev.js:1519lib$es6$promise$$internal$$publish @ angular2.dev.js:1490(anonymous function) @ angular2.dev.js:219microtask @ angular2.dev.js:10670run @ angular2.dev.js:138(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$asap$$flush @ angular2.dev.js:1301
angular2.dev.js:21835 TypeError: Cannot read property 'hostView' of undefined
    at tick (angular2.dev.js:19626)
    at Zone.run (angular2.dev.js:138)
    at Zone.run (angular2.dev.js:10644)
    at zoneBoundFn (angular2.dev.js:111)
    at lib$es6$promise$$internal$$tryCatch (angular2.dev.js:1507)
    at lib$es6$promise$$internal$$invokeCallback (angular2.dev.js:1519)
    at lib$es6$promise$$internal$$publish (angular2.dev.js:1490)
    at angular2.dev.js:219
    at microtask (angular2.dev.js:10670)
    at Zone.run (angular2.dev.js:138)BrowserDomAdapter.logError @ angular2.dev.js:21835ExceptionHandler.call @ angular2.dev.js:4434(anonymous function) @ angular2.dev.js:19543NgZone._onError @ angular2.dev.js:10711errorHandling.onError @ angular2.dev.js:10630run @ angular2.dev.js:141(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$$internal$$tryCatch @ angular2.dev.js:1507lib$es6$promise$$internal$$invokeCallback @ angular2.dev.js:1519lib$es6$promise$$internal$$publish @ angular2.dev.js:1490(anonymous function) @ angular2.dev.js:219microtask @ angular2.dev.js:10670run @ angular2.dev.js:138(anonymous function) @ angular2.dev.js:10644zoneBoundFn @ angular2.dev.js:111lib$es6$promise$asap$$flush @ angular2.dev.js:1301

编辑:

PeopleService 的简化版

//a simple service import {Injectable} from 'angular2/angular2';

@Injectable() export class PeopleService {
    people: any;
    constructor() {
        this.people = [
            {"id": 1, "name": "Brad"},
            {"id": 2, "name": "Jules"},
            {"id": 3, "name": "Jeff"}
        ]
    } }

Answer 1

错误是由 Typescript 编译器引起的。您必须将 people 定义为 PeopleService 的成员:

 //a simple service
import {Injectable} from 'angular2/angular2';
import {Http} from 'angular2/http';

@Injectable()
export class PeopleService {
  people: any;//-> this part is missing in your code.
  constructor(http:Http) {
    this.people = http.get('api/people.json').map(res => res.json());
  }
}

我不确定它是什么类型的数组，所以我把它设为 any。无论如何，它应该被定义为一个类成员。

编辑:

响应您对 PeopleService 中错误的编辑。尝试更新您的组件以像这样注入(inject)人员服务:

import {Component, View, CORE_DIRECTIVES} from 'angular2/angular2'
import {Inject} from 'angular2/core'; 
import {PeopleService} from './peopleService'  
import {Person} from './person'

@Component({  
    selector: 'my-app',  
    providers: [PeopleService]  
})  
@View({
    template: `
    <div>
      <h2>Hello Angular2!</h2>
      <my-person
        *ng-for="#person of people"
        [name]="person.name"
        (hello)="saidHello($event)">
      </my-person>
    </div>
  `,  
        directives: [CORE_DIRECTIVES, Person]  
})  
export class People {
    public peopleService: PeopleService;   

    constructor(@Inject(PeopleService) peopleService:PeopleService) {  
      this.peopleService = peopleService;  
      this.peopleService.people  
            .subscribe(people => this.people = people);  
    }  
    saidHello($event){  
        alert(`You said hello to ${$event}`)  
    }
}

注意构造函数中的 @Inject(PeopleService) 和它的新导入:

import {Inject} from 'angular2/core';

我推荐阅读这篇 awesome post关于 Angular 2 中的依赖注入(inject)，它对我帮助很大!