private int getCallState()
{
    int nState = 0;
    Class<TelephonyManager> c = TelephonyManager.class;
    Method getITelephonyMethod = null;
    try
    {
        getITelephonyMethod = c.getDeclaredMethod("getITelephony", (Class[]) null);
        getITelephonyMethod.setAccessible(true);
        TelephonyManager tManager = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
        Object iTelephony = (Object) getITelephonyMethod.invoke(tManager,(Object[]) null);
        Method getCallState = iTelephony.getClass().getDeclaredMethod("getCallState");
        nState = ((Integer) getCallState.invoke(iTelephony)).intValue();
    }
    catch (Exception e)
    {
        e.printStackTrace();
    }
    return nState;
}