Check Availability of Google Play Services

MainActivity.java

public class MainActivity extends Activity {
    @Override
    protected void onResume() {
        super.onResume();

        // code that doesn't require Google Play services

        if (!checkGooglePlayServices())
            return;

        // code that requires Google Play services
    }

    private boolean checkGooglePlayServices() {
        int result = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
        if (result == ConnectionResult.SUCCESS) {
            // the device has the latest Google Play services installed
            return true;
        } else {
            Dialog errorDialog = GooglePlayServicesUtil.getErrorDialog(result, this, 8964,
                new DialogInterface.OnCancelListener() {
                    @Override
                    public void onCancel(DialogInterface dialog) {
                        finish();
                    }
                });
            if (errorDialog != null) {
                // the problem can be fixed
                // e.g. the user needs to enable or download the latest version
                errorDialog.show();
            } else {
                // for some reason, the problem can't be fixed
                // you should provide some notice to the user
            }
            return false;
        }
    }

    @Override
    protected void onActivityResult (int requestCode, int resultCode, Intent data) {
        // you don't have to check it here,
        // since the onResume() callback will be invoked anyway
        if (requestCode == 8964) {
            // this is invoked when user finishes operation
            if (resultCode == Activity.RESULT_OK) {
                // problem fixed, now you can use Google Play services
            } else {
                // problem not fixed, e.g. user decides not to install the latest version
            }
        } else {
            super.onActivityResult(requestCode, resultCode, data);
        }
    }
}