Activity前后台切换

    private void startWinewApp() {
        String packageName = Settings.Global.getString(mContext.getContentResolver(), "FREATURE_AUTORUN_APK");
        if (packageName != null && packageName.length() > 0) {
            Intent launchIntent = mContext.getPackageManager().getLaunchIntentForPackage(packageName);
            launchIntent.addFlags(Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY); 
            mContext.startActivity(launchIntent);
        }
    }

这种更好：

    private void startWinewApp() {
         final ActivityManager am = (ActivityManager) mContext.getSystemService(Context.ACTIVITY_SERVICE);
         List<ActivityManager.RunningTaskInfo> recentList = am.getRunningTasks(30);
         for (ActivityManager.RunningTaskInfo info : recentList) {
                if (info.topActivity.getPackageName().equals(WINEW_APP_PACKAGE_NAME)) {
                    Log.d(TAG, "startWinewApp taskId="+info.id);
                    am.moveTaskToFront(info.id, ActivityManager.MOVE_TASK_WITH_HOME);
                    return;
                }
            }
        Intent launchIntent = mContext.getPackageManager().getLaunchIntentForPackage(WINEW_APP_PACKAGE_NAME);
        launchIntent.addFlags(Intent.FLAG_ACTIVITY_LAUNCHED_FROM_HISTORY
                | Intent.FLAG_ACTIVITY_NEW_TASK);
        try {
            mContext.startActivity(launchIntent);
        } catch (ActivityNotFoundException e) {
           Log.w(TAG, "Unable to launch recent winew", e);
        }
    }

将当前的Activity放到后台：

    private ActivityManager.RunningTaskInfo getTopTaskInfo() {
        ActivityManager activityManager = (ActivityManager) (mContext
                .getSystemService(Context.ACTIVITY_SERVICE));
        List<ActivityManager.RunningTaskInfo> runningTaskInfos = activityManager
                .getRunningTasks(1);
        if (runningTaskInfos != null) {
            return runningTaskInfos.get(0);
        }
        return null;
    }

    try {
        int taskId = getTopTaskInfo().id;
        ActivityManagerNative.getDefault().moveTaskToBack(taskId);    
    }catch (RemoteException e) {
    }