英文:
How to transform Stream<List<int>> to Stream<Uint8List> in Flutter
问题
我有一个来自包的Flutter函数，返回一个Stream<List<int>>，我想将其转换为Stream<Uint8List>。我对Dart Streams不太熟悉，所以我会感激有关这个主题的任何帮助/建议。
我已经尝试过cast()、as Stream<Uint8List>，但完全没有效果。
英文:
I have a Flutter function from a package that returns a Stream<List<int>> and I want to cast/transform to a Stream<Uint8List>. I'm not very familiar with dart Streams so I will appreciate any help/suggestion on this topic.
I have tried to cast(), as Stream<Uint8List>, but did not work at all.
答案1
得分: 3
以下是翻译好的部分：
"It's very likely that you have a Stream<List<int>> that already has Uint8List elements。如果是这样，您应该能够通过使用 Stream.cast 来将元素 (而不是 Stream 本身) 进行强制类型转换：
var uint8ListStream = originalStream.cast<Uint8List>();
如果这不起作用，那么您可以使用 Stream.map 从原始 Stream 中创建一个新的 Stream，将每个 List<int> 复制到新的 Uint8List 中：
var uint8ListStream = originalStream.map((list) => Uint8List.from(list));
您还可以使用上面链接的答案中的 asUint8List 来结合这些方法，只在必要时将其复制到新的 Uint8List 中：
var uint8ListStream = originalStream.map((list) => list.asUint8List());
英文:
It's very likely that you have a Stream<List<int>> that already has Uint8List elements. If so, you should be able to cast the elements (not the Stream itself) by using Stream.cast:
var uint8ListStream = originalStream.cast<Uint8List>();
If that doesn't work, then you can create a new Stream from the original with Stream.map, copying each List<int> into a new Uint8List:
var uint8ListStream = originalStream.map((list) => Uint8List.from(list));
You also could use asUint8List (from the answer I linked to above) to combine the approaches, copying into new Uint8Lists only if necessary:
var uint8ListStream = originalStream.map((list) => list.asUint8List());
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