flutter packages pub run build_runner build 失败报错,Deprecated. Use `dart run` instead. Could not find bin\build-runner.dart.

1.pubspec.yaml 添加 

dependencies:

  build_runner: ^2.4.6

2. flutter packages get

 

3. 创建build_runer

　　dart run build_runner build

4.flutter packages pub run build_runner build