如何杀死所有应用程序？

Question

如何像任务管理器中的“全部清除”按钮一样终止所有应用程序？

我试过了

Intent mainIntent = new Intent(Intent.ACTION_MAIN, null);
    mainIntent.addCategory(Intent.CATEGORY_LAUNCHER);
    List<ResolveInfo> pkgAppsList = getApplicationContext().getPackageManager().queryIntentActivities(mainIntent, 0);

    Process suProcess = Runtime.getRuntime().exec("su");
    DataOutputStream os = new DataOutputStream(suProcess.getOutputStream());
    os.writeBytes("adb shell" + "\n");
    os.flush();
    os.writeBytes("am force-stop " + pkgAppsList + "\n");
    os.flush();

和

ActivityManager activityManager = 
(ActivityManager)this.getSystemService(ACTIVITY_SERVICE);
activityManager.killBackgroundProcesses("com.google.android.youtube");

和

try {
        Process suProcess = Runtime.getRuntime().exec("su");
        DataOutputStream os = new DataOutputStream(suProcess.getOutputStream());
        os.writeBytes("adb shell" + "\n");
        os.flush();
        Context newContext = this;
        ActivityManager activityManager = (ActivityManager) newContext.getSystemService(Context.ACTIVITY_SERVICE);
        List<ActivityManager.RunningAppProcessInfo> appProcesses = activityManager.getRunningAppProcesses();
        for (ActivityManager.RunningAppProcessInfo appProcess : appProcesses) {
            if (appProcess.processName.equals("com.yourPackageName")) {
            } else {
                os.writeBytes("am force-stop " + appProcess.processName + "\n");
            }
        }
        os.flush();
        os.close();
        suProcess.waitFor();
    } catch (IOException ex) {
    } catch (SecurityException ex) {
    } catch (Exception ex) {
    }

也

ActivityManager actvityManager = (ActivityManager) getApplicationContext()
            .getSystemService(getApplicationContext().ACTIVITY_SERVICE);
    List<ActivityManager.RunningAppProcessInfo> procInfos = actvityManager
            .getRunningAppProcesses();
    for (int pnum = 0; pnum < procInfos.size(); pnum++) {
        actvityManager.killBackgroundProcesses(procInfos.get(pnum).processName);
    }

他们都没能杀死spotify。我该怎么做？我尝试过root和非root方法。