混合开发（Ionic/Cordova）：如何实现类似WhatsApp/Messenger的全屏来电视图？

Hey there, great question! Implementing that WhatsApp/Messenger-style full-screen incoming call UI for push notifications in Ionic or Cordova is totally achievable—let’s break down the tools and steps you’ll need:

First, you need a reliable way to receive push notifications (even when the app is in the background or killed). Here are the go-to options:

• Ionic (Capacitor): Use @capacitor/push-notifications—it’s the official Capacitor plugin, supports both iOS and Android, handles token registration, and lets you listen to the pushNotificationReceived event to trigger your custom UI when a push arrives.
• Cordova: Stick with phonegap-plugin-push—it’s the most mature and widely used Cordova push plugin, with full support for FCM (Android) and APNs (iOS), and includes event listeners for incoming pushes.

The tricky part is launching that overlay-style full-screen UI when a push hits. This varies by platform due to OS restrictions:

Android Specific Setup #

Android lets you display overlay windows over other apps, which is exactly what you need for the call UI:

• Custom Plugin: Build a custom Cordova/Ionic Android plugin that creates a translucent full-screen Activity. Set its theme to Theme.Translucent.NoTitleBar.Fullscreen to match the system call UI look, and add your own layout with call actions (accept/decline), contact info, etc.
• Key Permissions: You’ll need SYSTEM_ALERT_WINDOW (for overlay access—Android 10+ requires users to manually enable this via app settings) and WAKE_LOCK to wake the screen when the call comes in.
• Event Trigger: Hook into the push plugin’s notification received event to launch your custom Activity from the plugin code.

iOS Specific Setup #

iOS has stricter background rules, so you’ll need to use VoIP push notifications to bypass these limitations (regular push notifications can’t launch a full-screen UI from the background):

• VoIP Push Plugin: For Ionic/Capacitor, use @capacitor/voip-push (or build a custom iOS plugin) to handle VoIP push notifications. These are designed for voice calling apps and let you launch a full-screen UI even when the app is killed.
• Apple Developer Configuration: You’ll need to enable VoIP services in your Apple Developer account, and add the "Voice over IP" background mode to your app’s Info.plist.
• UI Implementation: Use a custom iOS ViewController (wrapped in your plugin) to create the full-screen call interface. When a VoIP push is received, present this ViewController over the current screen (or launch it directly from the background).
• Note: If your app isn’t a true VoIP service, Apple might reject it for using VoIP pushes. In that case, you can use interactive notifications with a custom action that opens a full-screen call UI, but it won’t be as seamless as the VoIP approach.

• Background Wakeup: Ensure your app can be woken up by pushes. For Android, add a BOOT_COMPLETED broadcast receiver to re-register push tokens after a device restart. For iOS, enable the "Remote notifications" background mode.
• Permission Handling: Always request necessary permissions upfront (push notifications, overlay access for Android, VoIP for iOS) and provide clear explanations to users—they’re more likely to grant access if they understand why you need it.
• UI Consistency: Match the platform’s native call UI style (Material Design for Android, Cupertino for iOS) to avoid confusing users.
• Testing: Use FCM to test Android pushes and APNs for iOS pushes. Test scenarios include app foreground, background, and completely killed to ensure the UI triggers every time.

内容的提问来源于stack exchange，提问作者Maxime B