Question

我有 appsettings.json

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

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

}

和数据库类

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，如何替换此行

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

具有来自appsettings的价值吗？

Answer 1

您可以为此使用DI。为此，您需要在Startup.cs中注册配置：

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

然后您可以将其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"));

另一个选项是使用“选项”模式。在这种情况下，您必须使用所需的属性创建一个类：

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

在启动时注册：

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);

如何简单地从appsettings.json中读取

1 个答案: