sgApp/src/app/app.component.ts

import { Component } from '@angular/core';
import { Platform, Events, AlertController } from '@ionic/angular';
import { SplashScreen } from '@ionic-native/splash-screen/ngx';
import { StatusBar } from '@ionic-native/status-bar/ngx';
import { Storage } from '@ionic/storage'
import { UserData } from '../providers/user-data';
import { Router } from '@angular/router';
import { LocalNotifications } from '@ionic-native/local-notifications/ngx';
// import { WebSocketService } from '../providers/WebSocketService';
import { Device } from '@ionic-native/device/ngx';
import { Update } from '../providers/update'

@Component({
  selector: 'app-root',
  templateUrl: 'app.component.html'
})
export class AppComponent {
  private loggedIn: boolean = false;
  private version_number: any
  constructor(
    private device: Device,
    private localNotifications: LocalNotifications,
    private router: Router,
    private events: Events,
    private update: Update,
    private userData: UserData,
    private storage: Storage,
    private platform: Platform,
    private alertController: AlertController,
    private splashScreen: SplashScreen,
    private statusBar: StatusBar,
    // private wsService: WebSocketService
  ) {
    this.initializeApp();
    // this.update.isUpdate()
    this.backButtonEvent()
  }
  ngOnInit() {
    this.initWebSocket()
    this.getVersionNumber()
    //WS连接的IP和端口提前保存在localStorage里，现在读出来
    // this.wsService.createObservableSocket(`ws://192.168.20.32:8804/websocket/403`);
    // this.wsService.sendMessage('testhis.fullScreenImaget')
    // this.getScanCode()
    this.checkLoginStatus()
    this.listenForLoginEvents()
  }

  getUserId(): Promise<string> {
    return this.storage.get('user_id').then((value) => {
      // this.update.isUpdate()
      return value;
    });
  }

 async getVersionNumber() {
    this.version_number =  await this.update.getVersionNumber()
  }

  async initWebSocket() {
    let _this = this
    let user_id = await this.getUserId()
    if (user_id) {
      let wsUrl = `ws://dev.sgsino.cn/websocket/${user_id}`
      let ws = new WebSocket(wsUrl)
      ws.onopen = function (evt) {
      }
      ws.onmessage = function (evt) {
        _this.localNotifications.schedule({
          text: evt.data,
          // trigger: {at: new Date(new Date().getTime() + 3600)},
          led: 'FF0000',
          sound: _this.device.platform == 'Android' ? 'file://sound.mp3' : 'file://beep.caf',
        });
      }
    }
  }

  // ngAfterContentInit() {
  //   this.appVersion.getVersionNumber().then((value: any) => {
  //     console.log(value)
  //   })
  // }
  ionViewDidLoad() {
  }

  getScanCode() {
    let _this = this
    let lastTime = null;
    let nextTime = null;
    let code = '';
    document.onkeydown = function (e) {
      let keycode = e.keyCode || e.which || e.charCode;
      nextTime = new Date();
      if (keycode === 13) {
        if (lastTime && (nextTime - lastTime < 30)) {
          // 扫码枪
          // do something
        } else {
          // 键盘
          // do something
        }
        code = '';
        lastTime = null;
        e.preventDefault();
      } else {
        if (!lastTime) {
          code = String.fromCharCode(keycode);
        } else {
          if (nextTime - lastTime < 30) {
            code += String.fromCharCode(keycode);
          } else {
            code = '';
          }
        }
        lastTime = nextTime;
      }
      if (code.split('_').length === 2) {
        _this.router.navigateByUrl('/enter-store')
        _this.storage.set('pId', code.split('_')[0])
        _this.storage.set('sscId', code.split('_')[1])
      }
      console.log(code)
    }
  }
  checkLoginStatus() {
    return this.userData.isLoggedIn().then(loggedIn => {
      return this.updateLoggedInStatus(loggedIn);
    });
  }
  updateLoggedInStatus(loggedIn: boolean) {
    setTimeout(() => {
      this.loggedIn = loggedIn;
    }, 300);
  }

  listenForLoginEvents() {
    this.events.subscribe('user:login', () => {
      this.initWebSocket()
      this.updateLoggedInStatus(true);
    });
    this.events.subscribe('user:logout', () => {
      this.updateLoggedInStatus(false);
    });
  }
  async logout() {
    this.userData.logout()
  }
  initializeApp() {
    this.platform.ready().then(() => {
      this.statusBar.styleDefault();
      this.splashScreen.hide();
    });
  }
  //android通过返回按钮退出应用
  lastTimeBackPress = 0;
  timePeriodToExit = 2000;
  backButtonEvent() {
    this.platform.backButton.subscribe(() => {
      if (this.router.url.indexOf('home') > -1 || this.router.url.indexOf('login') > -1 || this.router.url.indexOf('tab3') > -1) {
        if (new Date().getTime() - this.lastTimeBackPress < this.timePeriodToExit) {
          navigator['app'].exitApp(); //退出APP
        } else {
          this.presentAlertConfirm();
          this.lastTimeBackPress = new Date().getTime();
        }
        // navigator['app'].exitApp(); //ionic4 退出APP的方法
      }
    })
  }
  async presentAlertConfirm() {
    const alert = await this.alertController.create({
      // header: 'Confirm!',
      message: '您要退出APP吗?',
      buttons: [
        {
          text: '取消',
          role: 'cancel',
          cssClass: 'secondary',
          handler: (blah) => {
          }
        }, {
          text: '退出',
          handler: () => {
            navigator['app'].exitApp();
          }
        }
      ]
    });

    await alert.present();
  }
}