Question

我正在写一个角度为2的应用程序，我想缓存一些数据。当你去每个页面时，我经常打电话给服务设计师而不是传递现有的对象。

组件1：

import { Component, OnInit } from '@angular/core';
import { DataService } from '../services/globaldata.service'
import { User } from '../models/User';

@Component({
        selector: 'Campaigns',
        templateUrl: './campaigns.component.html',
        providers: [DataService]
})

export class CampaignComponent implements OnInit 
{
  public user: User;

  constructor(private dataService: DataService) 
  {
    this.user = dataService.getData();
  }
  ngOnInit() {
  this.user = this.dataService.getData();
  }
}

组件2：

import { Component, OnInit } from '@angular/core';
import { DataService } from '../services/globaldata.service'
import { User } from '../models/User';

@Component({
    selector: 'Wallet',
    templateUrl: './wallet.component.html',
    providers: [DataService] 
})
export class WalletComponent implements OnInit {

    public user: User;

    constructor(private dataService: DataService) {
        this.user = dataService.getData();
    }
    ngOnInit() {
        this.user = this.dataService.getData();
    }
}

服务

import { User } from '../models/user';
export class DataService
{
private data: User;

getData(): User {

    return this.data;
}
setData( price: number) {

    this.data = new User(price);
}
constructor() {
    this.data = new User(this.randomInteger(1,1000));
}


public randomInteger(min:number, max:number) {
    var rand = min - 0.5 + Math.random() * (max - min + 1)
    rand = Math.round(rand);
    console.log(rand);
    return rand;
}

每次导航时，控制台都会生成一个随机值，但在我看来，依赖注入应该缓存该值。可能是什么错误？

Answer 1

您的服务遗失@Injectable()：

它应该是这样的：

@Injectable()
export class DataService
{ ... }

Angular 2 Dependency注入不起作用

1 个答案: