如何在 Dart 中将 List<Asset> 数组转换为 List<File> 数组扑？答案

【问题标题】：How to convert List<Asset> Array to List<File> Array in Dart | Flutter?如何在 Dart 中将 List<Asset> 数组转换为 List<File> 数组扑？
【发布时间】：2021-08-01 11:38:31
【问题描述】：

我有基于 Flutter multi_image_picker: ^4.7.14 依赖的 List 数组。如何将 List Asset Array 转换为 List File Array？

这是代码

class _ConvertImageState extends State<ConvertImage> {
  List<Asset> images = List<Asset>();

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

  Future<void> pickImages() async {
    List<Asset> resultList = List<Asset>();

    try {
      resultList = await MultiImagePicker.pickImages(
        maxImages: 20,
        enableCamera: true,
        selectedAssets: images,
        materialOptions: MaterialOptions(
          selectCircleStrokeColor: "white",
          actionBarTitle: "Select Images",
          allViewTitle: "All Images",
          actionBarColor: "#3b3b3b",
          actionBarTitleColor: "white",
          statusBarColor: '#bbbbbb',

          selectionLimitReachedText: "You can select minimum 3 and maximum 20 images",
        ),
      );
    } on Exception catch (e) {
      print(e);
    }

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

  @override
  Widget build(BuildContext context) {......}
}

我可以用循环来做吗？请问，谁能告诉我正确的方法？

【问题讨论】：

标签： arrays list flutter file dart

【解决方案1】：

在这里我找到了答案。这是我的工作代码。我觉得是对的。

class _ConvertImageState extends State<ConvertImage> {
  List<Asset> images = List<Asset>();
  List<File> fileImageArray = [];

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

  Future<void> pickImages() async {
    List<Asset> resultList = List<Asset>();

    try {
      resultList = await MultiImagePicker.pickImages(
        maxImages: 20,
        enableCamera: true,
        selectedAssets: images,
        materialOptions: MaterialOptions(
          selectCircleStrokeColor: "white",
          actionBarTitle: "Select Images",
          allViewTitle: "All Images",
          actionBarColor: "#3b3b3b",
          actionBarTitleColor: "white",
          statusBarColor: '#bbbbbb',

          selectionLimitReachedText: "You can select minimum 3 and maximum 20 images",
        ),
      );
    } on Exception catch (e) {
      print(e);
    }

    setState(() {
      images = resultList;
      putToFileArray();
    });
  }

  void putToFileArray(){

    fileImagesArray.clear();
    images.forEach((imageAsset) async {
      final filePath =
      await FlutterAbsolutePath.getAbsolutePath(imageAsset.identifier);

      File tempFile = File(filePath);
      if (tempFile.existsSync()) {
        fileImageArray.add(tempFile);
      }
    });

  }

  @override
  Widget build(BuildContext context) {......}
}

FlutterAbsolutePathClass（依赖）

flutter_absolute_path：^1.0.6

链接：https://pub.dev/packages/flutter_absolute_path

打印数组

onPressed: () {
  print(fileImageArray.toString());
};

【讨论】：