/**
     * whether application is in background
     * <ul>
     * <li>need use permission android.permission.GET_TASKS in Manifest.xml</li>
     * </ul>
     *
     * @param context 上下文
     * @return if application is in background return true, otherwise return
     * false
     */
 

    public static boolean isApplicationInBackground(Context context) {
        ActivityManager am = (ActivityManager) context
                .getSystemService(Context.ACTIVITY_SERVICE);
        List<RunningTaskInfo> taskList = am.getRunningTasks(1);
        if (taskList != null && !taskList.isEmpty()) {
            ComponentName topActivity = taskList.get(0
 
).topActivity;
            if (topActivity != null
                    && !topActivity.getPackageName().equals(
                    context.getPackageName())) {
                return true;
            }
        }
        return false;
    }

    /**
     * whether application is Running
     * <ul>
     * <li>need use permission android.permission.GET_TASKS in Manifest.xml</li>
     * </ul>
     *
     * @param
 
 context 上下文
     * @return if application is running return true, otherwise return
     * false
     */
    public static boolean isApplicationRunning(Context context) {
        ActivityManager am = (ActivityManager) context
                .getSystemService(Context.ACTIVITY_SERVICE);
        List<RunningTaskInfo> taskList = am.getRunningTasks(1);
        if (taskList != null && !taskList.isEmpty()) {
            ComponentName topActivity = taskList.get(0).topActivity;
            if (topActivity != null
                    && !topActivity.getPackageName().equals(
                    context.getPackageName())) {
                return false;
            }
        }
        return true;
    }

    /**
     * 開啟應用
     * @param context
     * @param packageName
     */
    public static void openApp(Context context, String packageName) {
        try {
            PackageManager pm =  context.getPackageManager();
            PackageInfo pi = pm.getPackageInfo(packageName, 0);
            Intent resolveIntent = new Intent(Intent.ACTION_MAIN, null);
            resolveIntent.addCategory(Intent.CATEGORY_LAUNCHER);
            resolveIntent.setPackage(pi.packageName);
            List<ResolveInfo> apps = pm.queryIntentActivities(resolveIntent, 0);
            ResolveInfo ri = apps.iterator().next();
            if (ri != null ) {
                String packagename = ri.activityInfo.packageName;
                String className = ri.activityInfo.name;
                Intent intent = new Intent(Intent.ACTION_MAIN);
                intent.addCategory(Intent.CATEGORY_LAUNCHER);
                intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_NEW_TASK );//Intent.FLAG_ACTIVITY_RESET_TASK_IF_NEEDED
                ComponentName cn = new ComponentName(packagename, className);
                intent.setComponent(cn);
                context.startActivity(intent);
            }
        } catch (NameNotFoundException e) {
            e.printStackTrace();
        }
    }