Flutter异常Couldn‘t find dynamic library in default locations

Flutter项目在Windows系统使用ffigen生成代码时报下面的错误：

[SEVERE] : Couldn't find dynamic library in default locations.
[SEVERE] : Please supply one or more path/to/llvm in ffigen's config under the key 'llvm-path'.
Unhandled exception:
Exception: Couldn't find dynamic library in default locations.
#0      findDylibAtDefaultLocations (package:ffigen/src/config_provider/spec_utils.dart:371:3)
#1      Config._getRootConfigSpec.<anonymous closure> (package:ffigen/src/config_provider/config.dart:231:35)
#2      HeterogeneousMapConfigSpec._extractNode (package:ffigen/src/config_provider/config_spec.dart:320:16)
#3      ConfigSpec.extract (package:ffigen/src/config_provider/config_spec.dart:86:12)
#4      new Config.fromYaml (package:ffigen/src/config_provider/config.dart:192:22)
#5      new Config.fromFile (package:ffigen/src/config_provider/config.dart:201:19)
#6      getConfigFromCustomYaml (package:ffigen/src/executables/ffigen.dart:126:17)
#7      getConfig (package:ffigen/src/executables/ffigen.dart:78:14)
#8      main (package:ffigen/src/executables/ffigen.dart:48:14)
 

参考ffigen文档 ，安装LLVM以及Visual Studio（主要是下载C++），然后在ffigen.yaml文件中配置LLVM路径

llvm-path:- 'D:\LLVM'