Feature `xxx' cannot be used because it is not part of the C# 4.0 language specification
修改Unity项目使用的.NET版本
1、Unity编辑器中,点击菜单Edit -> Project Setting -> Player
2、找到Scripting Runtime Version* 选择对应的.NET 版本
Feature `xxx' cannot be used because it is not part of the C# 4.0 language specification
修改Unity项目使用的.NET版本
1、Unity编辑器中,点击菜单Edit -> Project Setting -> Player
2、找到Scripting Runtime Version* 选择对应的.NET 版本