ASP.NET核心实体框架空值连接字符串

Question

I want to connect my api to a SQL Server database. I am getting a null connection string value in my startup class. I totally don't know what I am doing wrong. Could you please check and let me know what should I correct? Thank you in advance.

Startup.cs

var connectionSettings = Configuration.GetSection("Connection").Get<ConnectionSettings>();

services.AddDbContextPool<Context>(
      options => options
            .UseSqlServer(connectionSettings.ConnectionString));

My appsettings.json connection is below:

"Connection": [
{
  "EFMode": "MSSQL",
  "DatabaseName": "Shop",
  "ConnectionString": "Server=(localdb)\\mssqllocaldb;Database=Shop;Trusted_Connection=True,MultipleActiveResultSets=True"
}

In Program.cs (main class):

var db = services.GetService<Context>();

if (db != null)
{
    var cs = services.GetService<ConnectionSettings>();
    db.Database.Migrate();

    var dt = services.GetService<DefaultTriggers>();
}

And my Context.cs :

var connectionSettings = config.GetSection("Connection").Get<ConnectionSettings>();

var optionsBuilder = new DbContextOptionsBuilder<Context>();
optionsBuilder.UseSqlServer(connectionSettings.ConnectionString);

return new Context(optionsBuilder.Options);

ConnectionSettings.cs

    public class ConnectionSettings
{
    public string ConnectionString { get; set; }
    public string DatabaseName { get; set; }
}

Answer 1

You either have to change your settings so that you have a single connection object (note that I've removed the [ array ] :

"Connection": {
  "EFMode": "MSSQL",
  "DatabaseName": "Shop",
  "ConnectionString": "Server=(localdb)\\mssqllocaldb;Database=Shop;Trusted_Connection=True,MultipleActiveResultSets=True"
}

Or you need to instruct the configuration object to load an array of ConnectionSettings :

var connectionSettings = Configuration.GetSection("Connection").Get<ConnectionSettings[]>();
var shopConnection = connectionSettings.First(s => s.DatabaseName == "Shop");

Answer 2

您可以简化获取连接字符串的方式，如下所示：

var connectionString = config["Connection:ConnectionString"];