netcore判断系统是哪种系统：

            Console.WriteLine("判断是否为Windows Linux OSX");
            Console.WriteLine($"Linux:{RuntimeInformation.IsOSPlatform(OSPlatform.Linux)}");
            Console.WriteLine($"OSX:{RuntimeInformation.IsOSPlatform(OSPlatform.OSX)}");
            Console.WriteLine($"Windows:{RuntimeInformation.IsOSPlatform(OSPlatform.Windows)}");