如何创建可以确定用户何时离开家的 android 应用程序？

Question

I want to create an application that can determine when a user is leaving their house and remind them to take a plastic bag. I have never created an application which uses the Google Maps SDK and am stumped as to how I can make the user set their location. Are there any resources like websites or books from where I can learn the skills I need to create such an app?

I want the final application to simply send a notification when the user has left their house.

Please do suggest an alternate method if you know one. For example, I thought of using wifi to send a notification, if the user leaves their house and disconnects from the wifi they will receive a notification.

Answer 1

Don't ask for location permission in your app, users are often reluctant to give this permission, unless they have a very good reason to do so.

Checking for WiFi disconnection seems like a good idea.

You can listen for changes in network connectivity using an intent filter with ConnectivityManager.CONNECTIVITY_ACTION . Register for these events in your main activity's onResume() :

IntentFilter filter = new IntentFilter(ConnectivityManager.CONNECTIVITY_ACTION);
this.getApplicationContext().registerReceiver(yourWifiBroadcastListener, filter);

And don't forget to unregister in onPause()

@Override
public void onPause() {
    this.getApplicationContext().unregisterReceiver(yourWifiBroadcastListener);
}

yourWifiBroadcastListener is an instance of your subclass of android.content.BroadcastReceiver in which you override onReceive() as needed:

@Override
public void onReceive(Context context, Intent intent) {

    //Check wether device is connected to WiFi network 
    //and notify user on disconnection 
}

Answer 2

This is actually a really difficult thing to do, especially just with software.

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GPS is maybe not the way - Consider that GPS does not work well indoors (it is 2D), and even A-GPS will have issues locating you accurately or at all in some areas, also polling GPS means you will likely get delayed updates, and it also kills battery, and added to that, no one wants you constantly tracking them so you can figure out if they need to bring a plastic bag, so perhaps you need some kind of proximity indicator instead.

Maybe listen for some kind of RF? - You could consider using BLE or UWB, and the User having a "beacon" in their home, that would be great in theory, but again no one will buy a beacon just to be reminded to bring a plastic bag.

Perhaps you could use the RSSI to their home wifi network (get them to identify it in your app), and when they are "far enough away" for a few seconds (or whatever works), send the notification - it's not perfect but if you combine it with other location solutions you could do something

You could combine approaches like these with the actual times that users typically leave their house - most people will go to work at the same time every day, maybe you could also set some kind of job to kick off at a "typical" time people leave the house, that might improve your performance a little