The configuration file 'appsettings.json' was not found and is not optional

问：

.Net Core: Application startup exception: System.IO.FileNotFoundException: The configuration file 'appsettings.json' was not found and is not optional.

 

答：

问题代码：

public Startup()

{

var builder = new ConfigurationBuilder().AddJsonFile("AppSetting.json");

Configuration = builder.Build();

}

 

 

正确代码：

public Startup(IHostingEnvironment environment)

{

var builder = new ConfigurationBuilder().SetBasePath(environment.ContentRootPath).AddJsonFile("AppSetting.json");

Configuration = builder.Build();

}