Flutter中通过REST API发送定时FCM推送：时间参数传递失败求助

一、FCM请求体中正确传递定时参数 #

你之前把event_time放在notification字段里是错误的，FCM用于定时推送的参数是**schedule_time，且必须放在请求体的根层级**，格式需遵循RFC3339标准（UTC时间，例如"2024-06-15T14:30:00Z"）。

修改后的完整请求体示例：

{
    "registration_ids": [
        "fNsi-sHiQDSWcNdx5Y2Nf9:APA91bEewR3VbuPVJO3qFDlcmqS6rp5fZilITgZJfl61JOsje6OEP13RjhxAn-0JRzf0-u8Mg-OBAKxRKtKRtpeisZagHJZsNYa_zat--1iyemwUSxdZIMRt2jxfZMiZ9Od4mk2DmznG",
        "fyYtfww_QzOTVh1aFyOaTZ:APA91bFih7TD9Q04kb03Ju1zUJ66N_2yMwo2dUCr_ZJJs-NKv3AaEAimGV2lxm7kgIsVlJSXRmrau-VFZ_52AS9tqobl-vP7iXbOOT35kdEFVEROMotr4AiksD2b5vE_TWWyai3BbH9E"
    ],
    "notification": {
        "body": "killed",
        "title": "killed title",
        "android_channel_id": "push_notification",
        "sound": false
    },
    "data": {
        "body": "data body",
        "title": "Data",
        "_id": 34534
    },
    "android": {
        "priority": "high"
    },
    "schedule_time": "2024-06-15T14:30:00Z"
}

关键注意点：

• schedule_time必须是未来的时间，且不能超过当前时间4周（FCM的最大定时范围）
• 时间格式必须为UTC标准，避免时区偏差导致推送时间错误

二、Flutter中通过REST API发送定时推送 #

使用Flutter的http包发起POST请求到FCM推送端点，步骤如下：

1. 在pubspec.yaml中添加http依赖：

dependencies:
  flutter:
    sdk: flutter
  http: ^1.2.1

2. 编写发送请求的代码：

import 'dart:convert';
import 'package:http/http.dart' as http;

Future<void> sendScheduledPushNotification() async {
  final String fcmServerKey = '你的FCM服务器密钥';
  final Uri fcmEndpoint = Uri.parse('https://fcm.googleapis.com/fcm/send');

  final Map<String, dynamic> requestBody = {
    "registration_ids": [
      "你的设备注册ID",
    ],
    "notification": {
      "body": "定时推送测试",
      "title": "定时通知",
      "android_channel_id": "push_notification",
      "sound": false
    },
    "data": {
      "body": "data body",
      "title": "Data",
      "_id": 34534
    },
    "android": {
      "priority": "high"
    },
    "schedule_time": "2024-06-15T14:30:00Z"
  };

  final response = await http.post(
    fcmEndpoint,
    headers: {
      'Content-Type': 'application/json',
      'Authorization': 'key=$fcmServerKey',
    },
    body: jsonEncode(requestBody),
  );

  if (response.statusCode == 200) {
    print('定时推送请求已提交成功');
    print('响应内容: ${response.body}');
  } else {
    print('请求失败，状态码: ${response.statusCode}');
    print('错误信息: ${response.body}');
  }
}

额外提醒：

• FCM服务器密钥需从Firebase控制台「项目设置」→「云消息传递」中获取
• 不要在客户端代码中硬编码服务器密钥（存在安全风险），建议通过你的后端服务转发请求，客户端仅调用后端接口
• 确保设备注册ID有效，否则会返回推送失败的响应

内容的提问来源于stack exchange，提问作者Som Gupta