Android 判斷通知欄是否打開及前往設置頁面

項目中用到日程提醒功能，如果應用的通知欄沒有打開，則需要提示用戶前去打開通知欄,判斷通知欄是否打開代碼如下：

 private boolean isNotificationEnabled(Context context) {

         String CHECK_OP_NO_THROW = "checkOpNoThrow";
         String OP_POST_NOTIFICATION = "OP_POST_NOTIFICATION";
         
        AppOpsManager mAppOps = (AppOpsManager) context.getSystemService(Context.APP_OPS_SERVICE);
        ApplicationInfo appInfo = context.getApplicationInfo();
        String pkg = context.getApplicationContext().getPackageName();
        int uid = appInfo.uid;

        Class appOpsClass = null;
      /* Context.APP_OPS_MANAGER */
        try {
            appOpsClass = Class.forName(AppOpsManager.class.getName());
            Method checkOpNoThrowMethod = appOpsClass.getMethod(CHECK_OP_NO_THROW, Integer.TYPE, Integer.TYPE,
                    String.class);
            Field opPostNotificationValue = appOpsClass.getDeclaredField(OP_POST_NOTIFICATION);

            int value = (Integer) opPostNotificationValue.get(Integer.class);
            return ((Integer) checkOpNoThrowMethod.invoke(mAppOps, value, uid, pkg) == AppOpsManager.MODE_ALLOWED);

        } catch (ClassNotFoundException e) {
            e.printStackTrace();
        } catch (NoSuchMethodException e) {
            e.printStackTrace();
        } catch (NoSuchFieldException e) {
            e.printStackTrace();
        } catch (InvocationTargetException e) {
            e.printStackTrace();
        } catch (IllegalAccessException e) {
            e.printStackTrace();
        }
        return false;
    }

返回值爲true時，通知欄打開，false未打開。

以下代碼爲前往設置頁面：

private void goToSet(){
        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.BASE) {
            // 進入設置系統應用權限界面
            Intent intent = new Intent(Settings.ACTION_SETTINGS);
            startActivity(intent);
            return;
        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {// 運行系統在5.x環境使用
            // 進入設置系統應用權限界面
            Intent intent = new Intent(Settings.ACTION_SETTINGS);
            startActivity(intent);
            return;
        }
    }

注：測試功能時發現，若在應用設置中關閉app的通知欄/不勾選顯示通知，則Toast無法顯示