c# - WebJobApp 中 EF 上下文的依赖注入(inject)

Question

我正在尝试创建我的第一个需要使用 Entity Framework 的网络作业应用程序。我试图将我的上下文注入(inject)应用程序的构建器，但出现错误:
无法将参数“db”绑定(bind)到 ApplicationDbContext 类型。确保绑定(bind)支持参数类型网上有几个示例，但 Azure WebJob 的版本似乎变化很快，我找不到适合我正在使用的版本的示例。这些是我正在使用的软件包版本:网络招聘3.0EF.NET 核心 7.0面向 .NET 7.0

这是我的代码:

 class Program
{
    static async Task Main()
    {
        var builder = new HostBuilder();
        builder.ConfigureWebJobs(b =>
        {
            b.AddTimers();
            b.AddAzureStorageCoreServices();
        });
        builder.ConfigureLogging((context, b) =>
        {
            b.AddConsole();
        });
        builder.ConfigureAppConfiguration((hostContext, configApp) =>
         {
             configApp.SetBasePath(Directory.GetCurrentDirectory());
             configApp.AddEnvironmentVariables(prefix: "ASPNETCORE_");
             configApp.AddJsonFile($"appsettings.json", true);
             configApp.AddJsonFile($"appsettings.{hostContext.HostingEnvironment.EnvironmentName}.json", true);

         });
       
       builder.ConfigureServices(services => { services.AddDbContext<ApplicationDbContext>(options => options.UseSqlServer("My full connection string"));
            services.AddTransient<IEmailSender, EmailSender>();
                                              });
        var host = builder.Build();
        using (host)
        //{
            await host.RunAsync();
        }
    }
}

public class Functions

public static void Sendemails([TimerTrigger("0 0 20 * * SUN-THU")] TimerInfo timer,
         ILogger logger,  ApplicationDbContext db)

    {
   
  
        var mylist = db.Users.ToList();
    
    }
}

我尝试使用以下代码而不是上面的代码来配置服务。检查构建器时，我可以看到服务已添加到构建器中。但是在调用 builder.Build() 后检查主机，服务不会显示在主机容器中。

var serviceCollection = new ServiceCollection();
ConfigureServices(serviceCollection);
     .....

  builder.ConfigureServices((context, sc) =>  sc= serviceCollection);
        var host = builder.Build();
   
        using (host)
        {
            await host.RunAsync();
        } 
}
 .....

    private void ConfigureServices(IServiceCollection services)
{
   
    services.AddDbContext<ApplicationDbContext>(options => options.UseSqlServer(_configuration.GetConnectionString("DefaultConnection")))
           
        
    }

项目文件

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
<OutputType>Exe</OutputType>
<TargetFramework>net7.0</TargetFramework>
<ImplicitUsings>enable</ImplicitUsings>
<Nullable>enable</Nullable>
  </PropertyGroup>

  <ItemGroup>
    <None Remove="appsettings.Development.json" />
    <None Remove="appsettings.json" />
  </ItemGroup>

  <ItemGroup>
    <Content Include="appsettings.Development.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <ExcludeFromSingleFile>true</ExcludeFromSingleFile>
      <CopyToPublishDirectory>PreserveNewest</CopyToPublishDirectory>
    </Content>
    <Content Include="appsettings.json">
      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
      <ExcludeFromSingleFile>true</ExcludeFromSingleFile>
      <CopyToPublishDirectory>PreserveNewest</CopyToPublishDirectory>
    </Content>
  </ItemGroup>

  <ItemGroup>
    <PackageReference 
Include="Microsoft.AspNetCore.Identity.EntityFrameworkCore" Version="7.0.1" />
    <PackageReference Include="Microsoft.Azure.WebJobs" Version="3.0.33" />
    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions" Version="4.0.1" />
    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.OpenApi.Configuration.AppSettings" Version="1.5.0" />
    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.SendGrid" Version="3.0.2" />
    <PackageReference Include="Microsoft.Azure.WebJobs.Extensions.Storage" Version="5.0.1" />
    <PackageReference Include="Microsoft.EntityFrameworkCore.SqlServer" Version="7.0.1" />
    <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="7.0.0" />
    <PackageReference Include="Microsoft.Extensions.Logging" Version="7.0.0" />
    <PackageReference Include="Microsoft.Extensions.Logging.Console" Version="7.0.0" />
    <PackageReference Include="Microsoft.Extensions.Options.ConfigurationExtensions" Version="7.0.0" />
    <PackageReference Include="SendGrid" Version="9.28.1" />
  </ItemGroup>

</Project>

Answer 1

最初即使我也遇到了同样的错误。

在 Program.cs 中进行了一些更改。

我的程序.cs:

using Microsoft.AspNetCore.Identity.UI.Services;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.Hosting;
using Microsoft.Extensions.Logging;

class Program
{
    static async Task Main()
    {
        var builder = new HostBuilder()
            .ConfigureWebJobs(b =>
            {
                b.AddTimers();
                b.AddAzureStorageCoreServices();
            })
            .ConfigureLogging((context, b) =>
            {
                b.AddConsole();
            })
             .ConfigureAppConfiguration((hostContext, configApp) =>
             {
                 configApp.SetBasePath(Directory.GetCurrentDirectory());
                 configApp.AddEnvironmentVariables(prefix: "ASPNETCORE_");
                 configApp.AddJsonFile($"appsettings.json", true);
                 configApp.AddJsonFile($"appsettings.{hostContext.HostingEnvironment.EnvironmentName}.json", true);
             })

        .ConfigureServices(services =>
        {
            services.AddDbContext<ApplicationDbContext>(
        options => options.UseSqlServer("MyDefaultConnection"));
            services.AddTransient<ApplicationDbContext, ApplicationDbContext>();
        });


        var host = builder.Build();
        using (host)
        {
            await host.RunAsync();
        }
    }
}

如果您在本地运行，请交叉检查 local.settings.json 文件一次。

我的local.settings.json:

{
  "IsEncrypted": false,
  "Values": {
    "AzureWebJobsStorage": "UseDevelopmentStorage=true",
    "FUNCTIONS_WORKER_RUNTIME": "dotnet"
  }
}

我的appsettings.json:

{
  "ConnectionStrings": {
    "AzureWebJobsStorage": "Storage Account Connection String"
  }
}

另请查看 SO Thread一次。

引用资料取自MSDoc .