从 webjob 配置 dbContext

Question

我有一个网站，它从发送给用户的电子邮件中获取输入（一封电子邮件发送给每个人，他们点击一个 link 调用控制器操作）。我想使用 webjob 发送电子邮件，但我需要循环遍历数据库中的所有用户以获取电子邮件地址。

我设置了网站，一切正常。我在这里有从 IdentityDbContext 继承的 DbContext：

public class MooodDbContext : IdentityDbContext<ApplicationUser>
    {
        public MooodDbContext(DbContextOptions options) : base(options)
        {

        }

        public DbSet<Response> Response { get; set; }

        public DbSet<Cow> Cow { get; set; }

        public DbSet<Herd> Herd { get; set; }
    }

当我启动 webapp

时，ConfigureServices 是运行

public void ConfigureServices(IServiceCollection services)
        {
            // Add framework services.
            services.AddDbContext<MooodDbContext>(options =>
                options.UseSqlServer(Configuration.GetConnectionString("MooodConnection")));

            services.AddIdentity<ApplicationUser, IdentityRole>()
                .AddEntityFrameworkStores<MooodDbContext>()
                .AddDefaultTokenProviders();

            services.AddMvc(options => options.Filters.Add(typeof(UnauthorizedExceptionFilterAttribute)));

            services.AddScoped<IDbInitializer, DbInitializer>();

            // Add application services.
            services.AddTransient<IEmailSender, AuthMessageSender>();
            services.AddTransient<ISmsSender, AuthMessageSender>();

        }

但显然不是当我运行网络作业时。因此，当我尝试访问上下文中的任何内容时，出现此异常（在设置 context = new context() 之后）：

System.InvalidOperationException occurred
  HResult=0x80131509
  Message=No database provider has been configured for this DbContext. A provider can be configured by overriding the DbContext.OnConfiguring method or by using AddDbContext on the application service provider. If AddDbContext is used, then also ensure that your DbContext type accepts a DbContextOptions<TContext> object in its constructor and passes it to the base constructor for DbContext.
  Source=Microsoft.EntityFrameworkCore

在我看来，这是因为我没有对 DbContext 进行任何配置，但我不确定。有没有更好的方法来完成这个？还是我遗漏了什么小东西？

编辑：这是我的 webjob 的 program.cs（减去电子邮件功能，这是混乱的）：

private static MooodDbContext _context;

        // Please set the following connection strings in app.config for this WebJob to run:
        // AzureWebJobsDashboard and AzureWebJobsStorage

        private static void Main()
        {
            _context = new MooodDbContext(new DbContextOptions<MooodDbContext>());

            var host = new JobHost();

            EmailAllHerds();

            host.RunAndBlock();

            EmailAllHerds();
        }

Answer 1

我在这里做出的几个假设

web job是一个基于.net core的console App

因此您将拥有 Program.cs 包含主要方法的文件。所以在你的

Program.cs

class Program {
   // declare a field to store config values
   private readonly IConfigurationRoot _configuration;
   // Declare a constructor 
   public Program()
   {
       var builder = new ConfigurationBuilder()
            .SetBasePath(environment.BasePath)
            .AddJsonFile($"appsettings.json", true, true)
            .AddJsonFile($"appsettings.{environment.EnvironmentName}.json", true, true)
            .AddEnvironmentVariables();

        _configuration = builder.Build();
   }
 }
  public static void Main(string[] args)
  {
     var program = new Program();
     var serviceCollection = new ServiceCollection();
     program.ConfigureServices(serviceCollection);           

  }

    private void ConfigureServices(IServiceCollection services)
    {
       // now here you can resolve your DbContext similar to web
      services.AddDbContext<MooodDbContext>(options =>options.UseSqlServer(_configuration.GetConnectionString("MooodConnection")));
    }
}

从 webjob 配置 dbContext

Configure a dbContext from a webjob

c#

entity-framework

azure

dbcontext

webjob