Ionic3 新增 Service

import {Injectable} from ‘@angular/core‘;

@Injectable()
export class SearchService {
  searchArea: string;
  constructor() {
    this.searchArea=‘广州市‘;
  }
}

import {NgModule} from ‘@angular/core‘;
import {SearchService} from "./search.service";

const services = [
  SearchService
];

@NgModule({
  imports: [],
  exports: [],
  declarations: [],
  providers: [...services]
})
export class ServiceModule {
}

import {NgModule} from ‘@angular/core‘;
import {ServiceModule} from "./service/service.module";

@NgModule({
  declarations: [],
  imports: [
    ServiceModule
  ],
  bootstrap: [],
  entryComponents: [],
  providers: []
})
export class AppModule {

}

import {Component} from ‘@angular/core‘;
import {NavController} from "ionic-angular";
import {SearchService} from "../../../app/service/search.service";

@Component({
  templateUrl: ‘choice.html‘,
})

export class SearchChoicePage {
  constructor(public navCtrl: NavController, private searchService: SearchService) {
  }

  returnArea(name: string) {
    this.searchService.searchArea = name;
    this.navCtrl.pop();
  }

}