Android, 如何让应用进入前台

Question

我正在尝试开发一项服务，只要用户打开应用程序，我的服务就会识别它。我正在使用文件：/proc/[pid]/cgroup,/proc/[pid]/cmdline,/proc/[pid]/oom_score,/proc/[pid]/oom_score _adj 检查它是否是前台的用户应用运行。实际上它在工作，但是当我尝试打开任何游戏时，服务不会一直识别它。（该服务仅识别具有最低值的文件 (oom_score)）。

示例：oom_score 对于 "com.google.android.googlequicksearchbox:interactor" 是 75，但是对于 "com.king.candycrushsaga" 将 >150，因此它永远不会被代码检测到（如下所示）。

服务代码：

scheduler.scheduleAtFixedRate(new Runnable() {
    @Override
    public void run() {
        s=appManager.getAppRunningForeground();
        System.out.println(s);
    }
},1,2,SECONDS);

获取应用的函数运行:

private ReadWriteFile readWriteFile = new ReadWriteFile();
public String getAppRunningForeground(){
    int pid;
    File[] files = new File("/proc").listFiles();
    int lowestOomScore = Integer.MAX_VALUE;
    String foregroundProcess = null;
    for (File file : files) {
        if (!file.isDirectory() || (!file.getName().matches(("\d+"))))
            continue;
        pid = Integer.parseInt(file.getName());
        try {
            String cgroup = readWriteFile.read(String.format("/proc/%d/cgroup", pid));
            String[] lines = cgroup.split("\n");
            if (lines.length != 2)
                continue;
            String cpuSubsystem = lines[0];
            String cpuaccctSubsystem = lines[1];
            if (!cpuaccctSubsystem.endsWith(Integer.toString(pid)) || cpuSubsystem.endsWith("bg_non_interactive"))
                continue;
            String cmdline = readWriteFile.read(String.format("/proc/%d/cmdline", pid));
            if (cmdline.contains("com.android.systemui")||cmdline.contains("com.google.android.googlequicksearchbox:interactor")) {
                continue;
            }
            int uid = Integer.parseInt(cpuaccctSubsystem.split(":")[2].split("/")[1].replace("uid_", ""));
            if (uid > 1000 && uid <= 1038)//System process
                continue;
            File oomScoreAdj = new File(String.format("/proc/%d/oom_score_adj", pid));
            if (oomScoreAdj.canRead()) {
                int oomAdj = Integer.parseInt(readWriteFile.read(oomScoreAdj.getAbsolutePath()));
                if (oomAdj != 0) {
                    continue;
                }
            }
            int oomscore = Integer.parseInt(readWriteFile.read(String.format("/proc/%d/oom_score", pid)));
            if (oomscore < lowestOomScore) {
                lowestOomScore = oomscore;
                foregroundProcess = cmdline.replaceAll("\p{Cntrl}", "");
            }

        } catch (IOException e) {
            e.printStackTrace();
        }
    }
    return foregroundProcess;
}

Class读取文件。

public class ReadWriteFile{
    File file;
    StringBuilder teste3 = new StringBuilder();
    FileOutputStream outputStream;
    public static String read(String path) throws IOException {
        StringBuilder output = new StringBuilder();
        BufferedReader reader = new BufferedReader(new FileReader(path));
        output.append(reader.readLine());
        for (String line = reader.readLine(); line != null; line = reader.readLine())
            output.append('\n').append(line);
        reader.close();
        return output.toString();
    }
}

P.S: getRunningTasks 已弃用，所以请不要推荐它。

Answer 1

可以使用UsageStatsManager class在android中添加api21.见 me.

提出并回答的问题

上面的回答会为你提供一个排序好的ArrayList应用，需要前台应用将ArrayList中的第一个放在索引号0上。

希望这会有所帮助。

Answer 2

这个方法可以帮到你

  void checkForegroundAppCompat()
        {
            ActivityManager activityManager = (ActivityManager) getSystemService(Context.ACTIVITY_SERVICE);
            final List<ActivityManager.RunningTaskInfo> taskInfo = activityManager.getRunningTasks(1);
            final ComponentName componentName = taskInfo.get(0).topActivity;
            if(!getWhiteListedPackages().contains(componentName.getPackageName()) &&
                    SecurityStatusManager.isAppsBlockingEnabled(this))
            {
                int pid = android.os.Process.getUidForName(componentName.getPackageName());
// Kill blick APP here               
  GRLog.w("KILL Blacklist App Package: " + componentName.getPackageName() + " with pid: " + pid);
                killApp(componentName.getPackageName(), pid);
            }
        }

Android, 如何让应用进入前台

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