android判断服务是否是运行状态

    /** 
         * 判断服务是否处于运行状态. 
         * @param servicename 
         * @param context 
         * @return 
         */  
        public static boolean isServiceRunning(String servicename,Context context){  
            ActivityManager am = (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);  
            List<RunningServiceInfo>  infos = am.getRunningServices(100);  
            for(RunningServiceInfo info: infos){  
                if(servicename.equals(info.service.getClassName())){  
                    return true;  
                }  
            }  
            return false;  
        }