firebase - Flutter无法上传从multi_image_picker获取的多张图像

Question

我已成功使用 multi_image_picker 获取多个图像，但未能将图像上传到 Firebase 存储。我请求有关将图像保存到 firebase 存储并返回 url 的帮助。

我已经在下面发布了我的代码，谢谢。

import 'package:flutter/material.dart';
import 'dart:async';
import 'package:firebase_storage/firebase_storage.dart';
import 'package:flutter/services.dart';
import 'package:multi_image_picker/multi_image_picker.dart';
import 'package:mock_data/mock_data.dart';



class PageTwo extends StatefulWidget {
  @override
  _MyAppState createState() => new _MyAppState();
}

class _MyAppState extends State<PageTwo> {
  List<Asset> images = List<Asset>();
  String popop = mockString(50);

  @override
  void initState() {
    super.initState();
  }

  Widget buildGridView() {
    return GridView.count(
      crossAxisCount: 3,
      children: List.generate(images.length, (index) {
        Asset asset = images[index];
        return AssetThumb(
          asset: asset,
          width: 300,
          height: 300,
        );
      }),
    );
  }

  Future saveImage(Asset asset) async {
    String fileName = popop;
    ByteData byteData = await asset.requestOriginal();
    List<int> imageData = byteData.buffer.asUint8List();
    StorageReference ref = FirebaseStorage.instance.ref().child(fileName);
    StorageUploadTask uploadTask = ref.putData(imageData);

    return await (await uploadTask.onComplete).ref.getDownloadURL();
  }

  Future<void> loadAssets() async {
    List<Asset> resultList = List<Asset>();
    try {
      resultList = await MultiImagePicker.pickImages(
          maxImages: 300,
          enableCamera: true,
          selectedAssets: images,
          cupertinoOptions: CupertinoOptions(takePhotoIcon: "chat"),
          materialOptions: MaterialOptions(
            actionBarColor: "#abcdef",
            actionBarTitle: "Example App",
            allViewTitle: "All Photos",
            selectCircleStrokeColor: "#000000",
          ));
    } 
    }
    if (!mounted) return;

    setState(() {
      images = resultList;
      _error = error;
    });
  }

  @override
  Widget build(BuildContext context) {
    return new MaterialApp(
      home: new Scaffold(
        appBar: new AppBar(
          title: const Text('Getting pics'),
        ),
        body: Column(
          children: <Widget>[
            RaisedButton(
              child: Text("Pick images"),
              onPressed: loadAssets,
            ),
            RaisedButton(
              child: Text("Save Image"),
              onPressed: () => saveImage,
            ),
            Expanded(
              child: buildGridView(),
            )
          ],
        ),
      ),
    );
  }
}

Answer 1

看起来您实际上并没有对该 URL 执行任何操作。 saveFile 上的 Future 不会返回任何内容，也不会将结果放在任何地方。

await (await uploadTask.onComplete).ref.getDownloadURL()

另外，等待等待看起来有点奇怪。您可能可以通过简单地级联 onComplete 等待来逃脱。我不完全确定但值得一试。

await uploadTask.onComplete..ref.getDownloadURL()

此外，当我使用 StorageUploadTask 时，我通常会监听任务来获取上传进度，然后添加 onComplete 部分来获取 downloadURL。