在android中获取系统后台运行的进程

//RunningServiceInfo
public static String getRunningServicesInfo(Context context) {
            StringBuffer serviceInfo = new StringBuffer();
            final ActivityManager activityManager = (ActivityManager) context
                            .getSystemService(Context.ACTIVITY_SERVICE);
            List<RunningServiceInfo> services = activityManager.getRunningServices(100);

            Iterator<RunningServiceInfo> l = services.iterator();
            while (l.hasNext()) {
                    RunningServiceInfo si = (RunningServiceInfo) l.next();
                    serviceInfo.append("pid: ").append(si.pid);
                    serviceInfo.append("\nprocess: "+si.process); 
                    serviceInfo.append("\nservice: ").append(si.service);
                    serviceInfo.append("\ncrashCount: ").append(si.crashCount);
                    serviceInfo.append("\nclientCount: ").append(si.clientCount);
                    serviceInfo.append("\nactiveSince: ").append(ToolHelper.formatData(si.activeSince));
                    serviceInfo.append("\nlastActivityTime: ").append(ToolHelper.formatData(si.lastActivityTime));
                    serviceInfo.append(";");
            }
            return serviceInfo.toString();
    }