将appsettings.json读取到定义了接口的对象中

public interface IDatabaseSettings
{
    string ConnectionString { get; }
}

"DatabaseSettings": {
    "ConnectionString": "your_connection_string"
}

public class DatabaseSettings : IDatabaseSettings
{
    public string ConnectionString { get; set; }

    public DatabaseSettings(IOptions<DatabaseSettings> options)
    {
        ConnectionString = options.Value.ConnectionString;
    }
}

public void ConfigureServices(IServiceCollection services)
{
    // 注册IDatabaseSettings接口和DatabaseSettings类
    services.Configure<DatabaseSettings>(Configuration.GetSection("DatabaseSettings"));
    services.AddSingleton<IDatabaseSettings, DatabaseSettings>();

    // 其他服务的注册和配置...
}

public class SomeService
{
    private readonly IDatabaseSettings _databaseSettings;

    public SomeService(IDatabaseSettings databaseSettings)
    {
        _databaseSettings = databaseSettings;
    }

    public void SomeMethod()
    {
        string connectionString = _databaseSettings.ConnectionString;
        // 使用连接字符串进行数据库操作...
    }
}