start example fail

[chenzefeng09]

按照readme启动example时，执行flutter run 失败。报错如下 ：

../lib/src/gesture/scroll_position_with_single_context.dart:37:7: Error: The non-abstract class 'ScrollPositionWithSingleContext' is missing implementations for these members:

• ViewportOffset.hasPixels
  Try to either
• provide an implementation,
• inherit an implementation from a superclass or mixin,
• mark the class as abstract, or
• provide a 'noSuchMethod' implementation.

class ScrollPositionWithSingleContext extends ScrollPosition implements ScrollActivityDelegate {
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
../../../flutter/packages/flutter/lib/src/rendering/viewport_offset.dart:96:12: Context: 'ViewportOffset.hasPixels' is defined here.
bool get hasPixels;
^^^^^^^^^

FAILURE: Build failed with an exception.

• Where:
  Script '/Users/chenzefeng/Development/flutter/packages/flutter_tools/gradle/flutter.gradle' line: 991

• What went wrong:
  Execution failed for task ':app:compileFlutterBuildDebug'.

Process 'command '/Users/chenzefeng/Development/flutter/bin/flutter'' finished with non-zero exit value 1

• Try:
  Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

• Get more help at https://help.gradle.org

BUILD FAILED in 14s

[andycall]

需要 flutter 1.22 以上版本

[yuanyan]

Flutter version in the kraken/pubspec.yaml

[chenzefeng09]

安装后报错：

E/DartVM (29022): vm-service: Error: Unhandled exception:
E/DartVM (29022): WebSocketException: Invalid WebSocket upgrade request
E/DartVM (29022):
E/flutter (29022): [ERROR:flutter/runtime/dart_isolate.cc(882)] Unhandled exception:
E/flutter (29022): WebSocketException: Invalid WebSocket upgrade request
Error connecting to the service protocol: failed to connect to
http://127.0.0.1:55543/ufXtD_4_LD0=/

[yuanyan]

重新安装下指定版本的 Flutter

[chenzefeng09]

flutter 的版本已经切到1.22.0了

[xmsz]

Flutter 2.0.3 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 4d7946a68d (4 days ago) • 2021-03-18 17:24:33 -0700
Engine • revision 3459eb2436
Tools • Dart 2.12.2

同样的错误

[abdulhamidalokzai]

@chenzefeng09 have you solved the problem?

[andycall]

flutter 2.0 现在还不支持，请切换到 1.22.4 版本