android: require password when uninstall app

Question

I want to build app like parental control, so when child try to uninstall/remove my app I would like to require that a user type a password before being allowed to uninstall/rem

Answer 1

You can lock the device if you use device administration. Users can't uninstall active device admins, then you can lock the device if they try to disable device admin, then the parent could type in the password to unlock it.

In your manifest:

  <receiver android:name=".AdminReceiver"
        android:label="Administration"
        android:description="@string/descript"
        android:permission="android.permission.BIND_DEVICE_ADMIN">
            <meta-data android:name="android.app.device_admin"
                       android:resource="@xml/deviceadmin" />
            <intent-filter>
                <action android:name="android.app.action.DEVICE_ADMIN_ENABLED" />
            </intent-filter>
        </receiver>

Then in @xml/deviceadmin

<device-admin xmlns:android="http://schemas.android.com/apk/res/android">
  <uses-policies>
    <reset-password />
    <force-lock />
  </uses-policies>
</device-admin>

Then

public class AdminReceiver extends DeviceAdminReceiver {
@Override
        public CharSequence onDisableRequested(final Context context, Intent intent) {

            Intent startMain = new Intent(Intent.ACTION_MAIN);
            startMain.addCategory(Intent.CATEGORY_HOME);
            startMain.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
            context.startActivity(startMain); //switch to the home screen, not totally necessary
            lockPhone(context, secPassword);
            //Log.i(TAG, "DEVICE ADMINISTRATION DISABLE REQUESTED & LOCKED PHONE");

            return "haha. i locked your phone.";
        }
    public static boolean lockPhone(Context context, String password){
        devAdminReceiver = new ComponentName(context, AdminReceiver.class);
        dpm = (DevicePolicyManager)context.getSystemService(Context.DEVICE_POLICY_SERVICE);
        boolean pwChange = dpm.resetPassword(password, 0);
        dpm.lockNow();
        return pwChange;
    }   
}

To enable your app as a device administrator:

devAdminReceiver = new ComponentName(context, AdminReceiver.class);
        dpm = (DevicePolicyManager)context.getSystemService(Context.DEVICE_POLICY_SERVICE);
        pref = PreferenceManager.getDefaultSharedPreferences(context);
        dpm.isAdminActive(devAdminReceiver);