一、安裝可檢測 APP 是否安裝的外掛

ionic cordova plugin add cordova-plugin-appavailability
npm install --save @ionic-native/app-availability

二、安裝可呼叫原生瀏覽器的外掛

ionic cordova plugin add cordova-plugin-inappbrowser
npm install --save @ionic-native/in-app-browser

三、引入到 app.module.ts

import { InAppBrowser } from
 
 '@ionic-native/in-app-browser';
import { AppAvailability } from '@ionic-native/app-availability';

···

providers: [
    InAppBrowser,AppAvailability
]

四、以 Home.ts 為例

import { Component } from '@angular/core';
import { IonicPage, NavController, NavParams } from 'ionic-angular';
import { InAppBrowser } from '@ionic-native/in-app-browser'
 
;
import { AppAvailability } from '@ionic-native/app-availability';
import { Platform } from 'ionic-angular';

@IonicPage()
@Component({
    selector: 'page-Home',
    templateUrl: 'Home.html',
})
export class Home {

    constructor(
        public navCtrl: NavController,
        public navParams: NavParams,
        private iab
 
: InAppBrowser,
        private appAvailability: AppAvailability, 
        private platform: Platform
    ) { }

    ionViewDidLoad() {
        var app = '';
        if (this.platform.is('ios')) {
            app = 'weixin://';      /* 微信的Scheme URL */
        } else if (this.platform.is('android')) {
            app = 'com.tencent.mm';     /* 微信的安卓包名 */
        }

        this.appAvailability.check(app)     /* 檢測微信是否已安卓 */
        .then(
            (yes: boolean) => {
                this.iab.create('weixin://', '_system');    /* 開啟微信 */
            },
            (no: boolean) => {
                /* 未安裝，請編寫提示程式碼或跳轉下載 */
            }
        );
    }
}