如何简单地阅读 appsettings.json

Question

我有appsettings.json

{
  "Logging": {
    "IncludeScopes": false,
    "LogLevel": {
      "Default": "Warning"
    }
  },

  "ConnectionString": "Server=...;Database=...;Trusted_Connection=True;"

}

和数据库 class

public class Database : DbContext
    {
        protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
            => optionsBuilder.UseSqlServer(@"Server=...;Database=...;Trusted_Connection=True;");

        protected override void OnModelCreating(ModelBuilder modelBuilder)
        {
            modelBuilder.Entity<Material>().ToTable("vw_Material", schema: "query");
        }

        public virtual DbSet<Material> Material { get; set; }
    }

我的问题是，如何替换这一行

optionsBuilder.UseSqlServer(@"Server=...;Database=...;Trusted_Connection=True;");

使用来自应用程序设置的值？

Answer 1

您可以使用 DI 来达到这个目的。为此，您需要在 Startup.cs:

中注册配置

public void ConfigureServices(IServiceCollection services)
{
   ...    
   services.AddSingleton<IConfiguration>(Configuration);
}

然后你可以将它注入数据库构造函数：

private readonly IConfiguration configuration;

public Database(IConfiguration config) 
{
    configuration = config;
}

并在配置时访问它：

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder.UseSqlServer(configuration.GetConnectionString("ConnectionString"));

另一种选择是使用选项模式。在这种情况下，您必须使用您需要的属性创建一个 class：

public class ConnectionStringConfig
{
    public string ConnectionString { get; set; }
}

启动时注册：

public void ConfigureServices(IServiceCollection services)
{
   ...    
   services.Configure<ConnectionStringConfig>(Configuration);
}

注入数据库构造函数：

private readonly ConnectionStringConfig configuration;

public Database(IOptions<ConnectionStringConfig> config) 
{
    configuration = config.Value;
}

并在配置时访问它：

protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
        => optionsBuilder.UseSqlServer(configuration.ConnectionString);

如何简单地阅读 appsettings.json

How to simply read from appsettings.json

c#

appsettings

.net-core

asp.net-core