无法在Android中的某些设备中获取gps位置

Question

在我的Android应用程序中，我试图通过点击按钮获取gps位置。我尝试了很多例子，但这些例子适用于某些设备。我正在测试的设备，即Micromax A90S，我无法获得它的位置。我无法找出究竟是什么问题。它是设备还是我需要在我的代码中进行一些更改？我正在使用的代码如下所示

protected void showCurrentLocation() {

    Location location = locationManager.getLastKnownLocation(LocationManager.GPS_PROVIDER);

    if (location != null) {
        String message = String.format(
                "Current Location \n Longitude: %1$s \n Latitude: %2$s",
                location.getLongitude(), location.getLatitude()
        );
        Toast.makeText(SettingsActivity.this, message,
                Toast.LENGTH_LONG).show();
    }

}   

private class MyLocationListener implements LocationListener {

    public void onLocationChanged(Location location) {
        String message = String.format(
                "New Location \n Longitude: %1$s \n Latitude: %2$s",
                location.getLongitude(), location.getLatitude()
        );
        Toast.makeText(SettingsActivity.this, message, Toast.LENGTH_LONG).show();
    }

    public void onStatusChanged(String s, int i, Bundle b) {
        Toast.makeText(SettingsActivity.this, "Provider status changed",
                Toast.LENGTH_LONG).show();
    }

    public void onProviderDisabled(String s) {
        Toast.makeText(SettingsActivity.this,
                "Provider disabled by the user. GPS turned off",
                Toast.LENGTH_LONG).show();
    }

    public void onProviderEnabled(String s) {
        Toast.makeText(SettingsActivity.this,
                "Provider enabled by the user. GPS turned on",
                Toast.LENGTH_LONG).show();
    }

}

请帮忙!!提前谢谢！