.Net Core 3.1 控制台应用程序读取appsettings.json

IConfigurationBuilder builder = new ConfigurationBuilder()

    .AddJsonFile($"appsettings.json", true, true);

IConfigurationRoot configuration = builder.Build();

DBConnectString config = configuration.GetSection("DBConnectString").Get<DBConnectString>();

optionsBuilder.UseSqlServer(config.DB);

一定要在csproj文件中添加如下代码（或者appsettings.json右键 copy to output directory选择 Copy always）

<ItemGroup> <None Update="appsettings.json"> <CopyToOutputDirectory>Always</CopyToOutputDirectory> </None> </ItemGroup>

此举的目的是在Release模式编译发布的时候带上appsettings.json，要不项目没有这个无法读取配置