需求 : 用户在未开启通知栏提醒时 , 提示用户去开启 . (有些手机默认是关闭了系统通知栏的)
(可写个弹窗,用来提示用户是否开启)
首先得判断用户是否已开启通知栏 :

  private static final String CHECK_OP_NO_THROW = "checkOpNoThrow";
  private static final String OP_POST_NOTIFICATION = "OP_POST_NOTIFICATION";
  @SuppressLint("NewApi")
  public static boolean isNotificationEnabled(Context context) {

    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true,表示已开启,false未开启
如果未开启,跳转到系统设置界面开启 (亲测,6.0系统可以使用)

    // 跳转到设置界面  开启通知栏
    private void getAppDetailSettingIntent(Context context) {
    Intent localIntent = new Intent();
    localIntent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
    if (Build.VERSION.SDK_INT >= 9) {
        localIntent.setAction("android.settings.APPLICATION_DETAILS_SETTINGS");
        localIntent.setData(Uri.fromParts("package", getPackageName(), null));
    } else if (Build.VERSION.SDK_INT <= 8) {
        localIntent.setAction(Intent.ACTION_VIEW);
        localIntent.setClassName("com.android.settings","com.android.settings.InstalledAppDetails");
        localIntent.putExtra("com.android.settings.ApplicationPkgName", getPackageName());
    }
    startActivity(localIntent);
}

资料是在 博客 上找到的,以下是原创地址:
http://blog.csdn.net/ylx_sheep/article/details/72548191