Question

我需要帮助，我正在使用 flutter 和 firebase 创建我的应用程序，在那里，我想将图像上传到 firebase 存储。所以我的文件

import 'package:firebase_storage/firebase_storage.dart';

 uploadTOFirebase() async {
    final ref = FirebaseStorage.instance.ref('posts/post_$postId.jpg');
    await ref.putFile(image).whenComplete(() async {
      final url = await ref.getDownloadURL();
      setState(() {
        postlink = url;
      });
      // print(postlink);
    });
  }

但是我看到了那个错误

E/flutter (19469): [ERROR:flutter/lib/ui/ui_dart_state.cc(186)] Unhandled Exception: NoSuchMethodError: The method 'ref' was called on null.
E/flutter (19469): Receiver: null
E/flutter (19469): Tried calling: ref("posts/post_27cfad88-62bb-4211-9e5b-0c6d1e9029be.jpg")
E/flutter (19469): #0      Object.noSuchMethod (dart:core-patch/object_patch.dart:54:5)
E/flutter (19469): #1      _UploadState.uploadTOFirebase (package:instaclone/pages/upload.dart:230:48)
E/flutter (19469): #2      _UploadState.HandleSubmit (package:instaclone/pages/upload.dart:226:11)
E/flutter (19469): <asynchronous suspension>
E/flutter (19469):

我在andoird中使用flutter

Answer 1

尝试像这样使用它。

final ref = FirebaseStorage.instance.ref().child("posts/post_$postId.jpg");

Answer 2

你有没有在任何地方给 Firebase.initializeApp() 打电话？否则，Firebase SDK 将无法在 Google 的服务器上找到您的项目。

有关如何执行此操作的示例，请参阅 FlutterFire 文档中的 initializing FlutterFire。

Answer 3

uploadTOFirebase() async {
    UploadTask storageUploadTask = FirebaseStorage.instance.putFile('posts/post_$postId.jpg');
    TaskSnapshot storageTaskSnapshot =
        await storageUploadTask.whenComplete(() => null);
    String url = await storageTaskSnapshot.ref.getDownloadURL();
    setState((){postlink = url;});
  }

试试这个代码。做了一些小改动。

NoSuchMethodError: 方法 'ref' 在 null 上被调用

3 个答案: