Question

I want to make an application that would display a message when a user unlocks his/her Android phone. I do not know if this is possible or not.

If anyone has a way to do this, could you please point me in the right direction.

Answer 1

Yes you can do this

In your manifest file write this,

receiver android:name=".MyBroadCastReceiver" >
        <intent-filter>
            <action android:name="android.intent.action.BOOT_COMPLETED" />

            <category android:name="android.intent.category.HOME" />

            <action android:name="android.intent.action.SCREEN_ON" />
            <action android:name="android.intent.action.USER_PRESENT" />
        </intent-filter>
    </receiver>

and MyBroadCastReceiver implementation is like this

public class MyBroadCastReceiver extends BroadcastReceiver {

    Context mContext;

    @Override
    public void onReceive(Context context, Intent intent) {
        mContext = context;
        Toast.makeText(mContext, "Phone UNLOCKED", Toast.LENGTH_LONG)
                .show();

    }

}