从extended_image 的 editorKey中快速拿图片数据.

get_uint8List.dart

  static Future<Uint8List> getImageFromEditorKey(
      GlobalKey<ExtendedImageEditorState> editorKey) async {
    Uint8List result;
    final provider =
        editorKey.currentState.widget.extendedImageState.imageProvider;
    if (provider is AssetImage) {
      ByteData byteData;
      if (provider.package == null) {
        byteData = await rootBundle.load(provider.assetName);
      } else {
        byteData = await rootBundle
            .load("packages/${provider.package}/${provider.assetName}");
      }
      result = byteData.buffer.asUint8List();
    } else if (provider is FileImage) {
      result = provider.file.readAsBytesSync();
    } else if (provider is MemoryImage) {
      result = provider.bytes;
    } else if (provider is NetworkImage) {
      final client = HttpClient();
      final req = await client.getUrl(Uri.parse(provider.url));
      for (final key in provider.headers.keys) {
        final value = provider.headers[key];
        req.headers.add(key, value);
      }
      final response = await req.close();
      final listList = await response.toList();
      List<int> tmp = [];
      for (final list in listList) {
        tmp.addAll(list);
      }
      result = Uint8List.fromList(tmp);
      client.close();
    } else if (provider is ExtendedNetworkImageProvider) {
      final file = await getCachedImageFile(provider.url);
      if (file != null) {
        result = file.readAsBytesSync();
      } else {
        final client = HttpClient();
        final req = await client.getUrl(Uri.parse(provider.url));
        for (final key in provider.headers.keys) {
          final value = provider.headers[key];
          req.headers.add(key, value);
        }
        final response = await req.close();
        final listList = await response.toList();
        List<int> tmp = [];
        for (final list in listList) {
          tmp.addAll(list);
        }
        result = Uint8List.fromList(tmp);
        client.close();
      }
    } else {
      result = (await editorKey.currentState.image.toByteData())
          .buffer
          .asUint8List();
    }

    return result;
  }