[英]Injector not working as expected in Angular2/Ionic2
我已經定義了如下服務:
//storageService.ts
import { Injectable } from '@angular/core';
import {Storage, SqlStorage} from 'ionic-angular';
@Injectable()
export class StorageService {
storage: any;
constructor() {
this.storage = new Storage(SqlStorage);
}
getUser() {
return this.storage.get('user');
}
}
我將其注入另一個類,如下所示:
Profile.ts
import {StorageService} from '../../services/storageService';
@Page({
templateUrl: 'build/pages/profile/profile.html',
providers: [StorageService]
})
export class ProfilePage {
constructor(private http: Http, storageService: StorageService) {
this.storageService.getUser().then(user => {
this.user = JSON.parse(user);
}).catch(error => {
console.log(error);
});
}
}
但是我一直收到錯誤:
Cannot read property 'getUser' of undefined
由於我將服務注入到構造函數中,所以我收到此錯誤?
因為您正在使用TypeScript,所以需要在構造函數中將提供程序定義為private
或public
,這將在頁面類中自動創建提供程序的實例,例如:
constructor(private http: Http, private storageService: StorageService) {
this.storageService.getUser().then(user => {
this.user = JSON.parse(user);
}).catch(error => {
console.log(error);
});
}
對您問題的其他答復提供了JavaScript解決方案,該解決方案對您不起作用。
據我所知,您需要在Ionic中使用靜態parameters
,例如:
@Page({
templateUrl: 'build/pages/profile/profile.html',
providers: [StorageService]
})
export class ProfilePage {
static get parameters() {
return [[Http], [StorageService]];
}
constructor(private http: Http, storageService: StorageService) {
this.storageService.getUser().then(user => {
this.user = JSON.parse(user);
}).catch(error => {
console.log(error);
});
}
}
顯然我沒有正確使用打字稿。
必須聲明如下的storageService:
constructor(private http: Http,private storageService: StorageService) {
即我錯過了私人關鍵字
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