Indication when ap moves to background, when packages gets installed

Am writing an android application which in background will monitor the device.I want to get an indication whenever an application moves to background/foreground.Also 开发者_如何学JAVAI want to get an indication when an application installed or gets uninstalled from the android device. how can this be acheived in android ?please help .thank you

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For the app moving to the background/foreground part of the question: AFAIK there is no way to do this for apps other than your own, which is what I think you are wanting here.

For the install/uninstall detection, you'll need to register a BroadcastReceiver in your app to receive the ACTION_PACKAGE_ADDED & ACTION_PACKAGE_REMOVED intents. Something like:

BroadcastReceiver br = new BroadcastReceiver() {            
    @Override
    public void onReceive(Context context, Intent intent) {
        // Your implementation                
    }
};

registerReceiver(br, new IntentFilter(Intent.ACTION_PACKAGE_ADDED));
registerReceiver(br, new IntentFilter(Intent.ACTION_PACKAGE_REMOVED));

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For the foreground/background part of your question have a look at the "Activity Lifecycle".

For notifications about installs and uninstalls you can register a BroadcastReceiver for the events Intent.ACTION_PACKAGE_ADDED and Intent.ACTION_PACKAGE_REMOVED

Something like

registerReceiver(new BroadcastReceiver() {

    public void onReceive(Context context, Intent intent) {
      // do something
    }

}, new IntentFilter(Intent.ACTION_PACKAGE_ADDED));