供應商在Ionic2/Angular2中的應用程序

Question

我有兩個供應商。

1. AppStorage負責設置並從存儲中獲取值。

   import { Injectable } from '@angular/core'; 
   import {Http, Headers, RequestOptions} from '@angular/http'; 
   import {Observable} from 'rxjs/Rx'; 
   import {Storage} from '@ionic/storage'; 
   
   @Injectable() 
   export class AppStorage { 
   
       constructor(public http: Http, private storage:Storage) { 
       console.log('Hello Appstorage Provider'); 
       } 
       setValue(key,value){ 
       var setPromise = new Promise((resolve,reject)=>{this.storage.set(key,value).then((res)=>{ 
        return resolve(res); 
       }) 
       }); 
       return setPromise; 
       }; 
       getValue(key){ 
       var getPromise = new Promise((resolve,reject)=>{this.storage.get(key).then((val)=>{ 
        return resolve(val); 
        }); 
       }); 
       return getPromise; 
   
       } 
   } 
   

2. OauthService這是我的api服務。

   import {Http, Headers, RequestOptions} from '@angular/http'; 
   import { Injectable, Inject} from '@angular/core'; 
   import 'rxjs/add/operator/map'; 
   import { AppStorage } from '../providers/appstorage'; 
   
   @Injectable() 
       export class OauthService{ 
       http: Http; 
       response :any; 
       appStorage: AppStorage; 
       static get parameters() { 
        return [[Http]]; 
       } 
       constructor(http: Http,@Inject(AppStorage) appStorage: AppStorage){ 
       this.http = http; 
        this.appStorage = appStorage; 
        setTimeout(()=>{ 
         console.log('Hello OauthService Provider'+this.appStorage+"===="+this.http); 
        },3000) 
       //output - >Hello OauthService Providerundefined====[object Object] 
       } 
       } 
   

現在我將兩個注射到我的app.module

import { NgModule, ErrorHandler } from '@angular/core'; 
import { IonicApp, IonicModule, IonicErrorHandler } from 'ionic-angular'; 
import { MyApp } from './app.component'; 
import { LoginPage } from '../pages/login/login'; 
import { AppStorage } from '../providers/appstorage'; 
import { Storage } from '@ionic/storage'; 
import { OauthService } from '../providers/oauthservice'; 

@NgModule({ 
    declarations: [ 
    MyApp, 
    LoginPage 
    ], 
    imports: [ 
    IonicModule.forRoot(MyApp) 
    ], 
    bootstrap: [IonicApp], 
    entryComponents: [ 
    MyApp, 
    LoginPage 
    ], 
    providers: [{provide: ErrorHandler, useClass: IonicErrorHandler},OauthService, Storage, AppStorage] 
}) 
export class AppModule {} 

但是，當我運行的應用程序，在oauthService的構造函數中appStorage對象來爲未定義。 你能告訴我我正在做什麼錯誤，我只是在另一項服務中注入服務。

Answer 1

你的靜態參數吸氣（參數）在OauthService提供商應該包括所有你注入到構造的供應商。但是，您只注入了Http提供程序，但不提供AppStorage提供程序。 我已經修改相應的代碼如下：

import { Http } from '@angular/http'; 
import { Injectable } from '@angular/core'; 
import 'rxjs/add/operator/map'; 
import { AppStorage } from './appstorage'; 

@Injectable() 
export class OauthService { 

    response :any; 

    static get parameters() { 
     return [[Http], [AppStorage]]; 
    } 

    constructor(private http: Http, private appStorage: AppStorage) { 

     setTimeout(() => { 
      console.log('Hello OauthService: appStorage=' + this.appStorage + ", http=" + this.http); 
     }, 3000) 
     //output - >Hello OauthService: appStorage=[object Object], http=[object Object] 
    } 
}