Great question! The warning you're seeing comes from the native iOS Firestore SDK, and Flutter's cloud_firestore plugin does support configuring this setting—you just need to use the Dart-specific API instead of the native iOS syntax.

Here's how to fix it, depending on your cloud_firestore version:

For older versions (pre-v1.0, using Firestore class) #

If you're using the legacy Firestore.instance accessor, use the settings() method to enable the timestamp behavior:

static Firestore getStartupFirestore() {
  var fs = Firestore.instance;
  // Enable the timestamp snapshot behavior
  fs.settings(timestampsInSnapshotsEnabled: true);
  return fs;
}

For newer versions (v1.0+, using FirebaseFirestore class) #

After Firebase's core initialization, configure the settings via the settings property:

import 'package:firebase_core/firebase_core.dart';
import 'package:cloud_firestore/cloud_firestore.dart';

static Future<FirebaseFirestore> getStartupFirestore() async {
  // First initialize Firebase core (required for v1.0+)
  await Firebase.initializeApp();
  
  var fs = FirebaseFirestore.instance;
  // Set the timestamp behavior
  fs.settings = const Settings(timestampsInSnapshotsEnabled: true);
  
  return fs;
}

Important Notes: #

• Name difference: Notice the Dart parameter is timestampsInSnapshotsEnabled (without the leading are), which maps to the native iOS areTimestampsInSnapshotsEnabled setting.
• Update your data handling: Once enabled, Firestore will return Timestamp objects instead of DateTime for timestamp fields. You'll need to adjust your code to convert them:

  // Old code (expecting DateTime)
  // DateTime createdAt = doc.data()['created_at'] as DateTime;
  
  // New code (handling Timestamp)
  Timestamp timestamp = doc.data()['created_at'] as Timestamp;
  DateTime createdAt = timestamp.toDate();
  

• Default behavior in recent versions: In newer releases of cloud_firestore, this setting is enabled by default. If you're still seeing the warning, explicitly setting it will suppress the message and ensure consistent behavior across versions.

内容的提问来源于stack exchange，提问作者babernethy