Android L 之后Google收紧了权限的控制 .

1）getRunningAppProcesses代替方法

这时我们可以尝试通过ps命令来获取后台运行的进程

private static  String getRunningApk() {
    long startTime = System.currentTimeMillis();
    String pgkProcessAppMap = "";
    Set<String> rProcess = new HashSet<String>();
    String cmd = "ps";
    try {
        java.lang.Process p = Runtime.getRuntime().exec(cmd);
        BufferedReader in = new BufferedReader(new InputStreamReader(p.getInputStream()));
        String line = null;
        int index = 0;
        while ((line = in.readLine()) != null) {
            if (index > 0) {
                StringTokenizer st = new StringTokenizer(line);
                int lenght = st.countTokens();
                if (lenght > 0) {
                    String uid = st.nextToken();//0 index USER
                    if (uid.startsWith("u0_") ) {
                        String processInfo = "";
                        for (int i = 0; i < (lenght - 1); i++) {
                            if (!(i == (lenght - 2))) {
                                st.nextToken();
                            } else {
                                processInfo = st.nextToken();
                            }
                        }
                        
                        if (!TextUtils.isEmpty(processInfo)) {
                            if (processInfo.contains(":")) {
                                String a[] = processInfo.split(":");
                                rProcess.add(a[0]);
                            } else {
                                rProcess.add(processInfo);
                            }
                        }
                        
                    }
                }
            }
            index++;
        }
    } catch (IOException e) {
        Log.logE("getRunningApk err="+e.toString());
    }
    for(String pro : rProcess){
        pgkProcessAppMap += pro + ",";
    }
    if (pgkProcessAppMap.contains(",") && pgkProcessAppMap.length() > 0 ) {
        pgkProcessAppMap = pgkProcessAppMap.substring(0, pgkProcessAppMap.length()-1);
    }
    long endTime = System.currentTimeMillis();
    Log.logE("do_exec pgkProcessAppMap = " + pgkProcessAppMap + "\t time = " + (endTime - startTime));
    return pgkProcessAppMap;
}

2）getRunningTasks代替方法

google发现API 21 新增的接口 android.app.usage , 这个 API 比已弃用的 getRecentTasks( ) 方法提供了更详细信息

@TargetApi(21)
public static String getTopPackageNameFor21(Context mContext) {
    String topPackageName = "";
    android.app.usage.UsageStatsManager usm = (android.app.usage.UsageStatsManager) mContext.getSystemService("usagestats");
    Calendar calendar = Calendar.getInstance();
    long endTime = calendar.getTimeInMillis();
    long startTime = calendar.getTimeInMillis() - 60*1000;

    //Log.logD(" Range start:" + dateFormat.format(startTime) );
    //Log.logD(" Range   end:" + dateFormat.format(endTime));
    android.app.usage.UsageEvents uEvents = usm.queryEvents(startTime,endTime);
    
    while (uEvents.hasNextEvent()){
        android.app.usage.UsageEvents.Event e = new android.app.usage.UsageEvents.Event();
        uEvents.getNextEvent(e);
        if (e != null){
             //Log.logE(" Event: " + dateFormat.format(e.getTimeStamp()) + "::" +  e.getPackageName());
             topPackageName = e.getPackageName();
        }
    }
    return topPackageName;
}

注： 必须要在manifest中申明权限

<uses-permission android:name="android.permission.PACKAGE_USAGE_STATS" />

The End！

Anyway,小编第一次这上面写文章，总有发表一下感言的，哈哈。虽然网络上以已经有很多类似的啦，不过小编还是写了一下，不为别的，就是给自己补补脑。Bye~