.NET 8 Worker模式Azure Functions集成AspNetCore后无法配置Newtonsoft序列化器

将Azure Functions从进程内模式迁移至带AspNetCore集成的Worker隔离模式后，无法将序列化器设置为Newtonsoft.Json以保留[FromBody]特性的原有行为。

现有代码 #

Program.cs #

IHost host = new HostBuilder()
    .ConfigureFunctionsWebApplication(workerAppBuilder =>
    {
        workerAppBuilder.UseWhen<AuthorizationMiddleware>(c =>
        {
            string triggerType = c.FunctionDefinition.InputBindings.Values.First(a => a.Type.EndsWith("Trigger", StringComparison.Ordinal)).Type;
            return string.Equals(triggerType, "httpTrigger", StringComparison.Ordinal);
        });
    })
    .ConfigureAppConfiguration(builder =>
    {
        builder.SetBasePath(Directory.GetCurrentDirectory())
               .AddJsonFile("local.settings.json", optional: true, reloadOnChange: true)
               .AddEnvironmentVariables()
               .AddUserSecrets(Assembly.GetExecutingAssembly(), optional: true);
    })
    .ConfigureServices((context, services) => ConfigureServices(services, context.Configuration))
    .ConfigureLogging(builder => builder.AddFilter<ApplicationInsightsLoggerProvider>(string.Empty, LogLevel.Information))
    .Build();

await host.RunAsync();


static void ConfigureServices(IServiceCollection services, IConfiguration configuration)
{
    services.AddApplicationInsightsTelemetryWorkerService();
    services.ConfigureFunctionsApplicationInsights();
    // 其他服务注册..
}

HttpTrigger函数示例 #

using FromBodyAttribute = Microsoft.Azure.Functions.Worker.Http.FromBodyAttribute;

public async Task<IActionResult> RunAsync(
    [HttpTrigger(
        AuthorizationLevel.Anonymous,
        "post",
        Route = "companies/search")]
    HttpRequest request,
    [FromBody] SearchCompaniesQuery searchCompaniesQuery,
    CancellationToken ct)
{
    return new OkObjectResult(await companyService.SearchCompaniesAsync(searchCompaniesQuery, ct));
}

已尝试的解决方案 #

• 方案1：在ConfigureServices中添加以下代码，可运行但无官方文档支持，存在兼容性顾虑

  services.AddMvcCore().AddNewtonsoftJson();
  

  已安装Microsoft.AspNetCore.Mvc.NewtonsoftJson 8.0.0版本

• 方案2：修改ConfigureFunctionsWebApplication配置

  .ConfigureFunctionsWebApplication(workerAppBuilder => workerAppBuilder.UseNewtonsoftJson())
  

• 方案3：配置WorkerOptions指定全局序列化器

  .ConfigureServices((context, services) =>{
  
      services.Configure<WorkerOptions>(workerOptions =>
      {
          JsonSerializerSettings settings = NewtonsoftJsonObjectSerializer.CreateJsonSerializerSettings();
          settings.ContractResolver = new CamelCasePropertyNamesContractResolver();
          settings.NullValueHandling = NullValueHandling.Ignore;
  
          workerOptions.Serializer = new NewtonsoftJsonObjectSerializer(settings);
      }) 
      
  })
  

当前异常信息 #

[2023-12-06T09:35:04.528Z] Function 'createOrUpdate', Invocation id '172f2590-9810-48b0-8fa7-bdb1b02b1ea6': An exception was thrown by the invocation.
[2023-12-06T09:35:04.530Z] Result: Function 'createOrUpdate', Invocation id '172f2590-9810-48b0-8fa7-bdb1b02b1ea6': An exception was thrown by the invocation.
Exception: System.InvalidOperationException: The JSON value could not be converted to System.Nullable`1[System.Guid]. Path: $.repeatIntervalUnitsId | LineNumber: 0 | BytePositionInLine: 27.
[2023-12-06T09:35:04.534Z]
[2023-12-06T09:35:04.536Z]    at Microsoft.Azure.Functions.Worker.Extensions.Http.AspNetCore.FromBodyConverstionFeature.ConvertAsync(FunctionContext context, Type targetType) in D:\a\_work\1\s\extensions\Worker.Extensions.Http.AspNetCore\src\FromBodyConverstionFeature.cs:line 91
[2023-12-06T09:35:04.537Z]    at Microsoft.Azure.Functions.Worker.Extensions.Http.Converters.FromBodyConverter.HandleResultAsync(ValueTask`1 result) in D:\a\_work\1\s\extensions\Worker.Extensions.Http\src\FromBodyConverter.cs:line 28
[2023-12-06T09:35:04.548Z]    at Microsoft.Azure.Functions.Worker.Context.Features.DefaultInputConversionFeature.AwaitAndReturnConversionTaskResult(ValueTask`1 conversionTask) in D:\a\_work\1\s\src\DotNetWorker.Core\Context\Features\DefaultInputConversionFeature.cs:line 103
[2023-12-06T09:35:04.549Z] Executed 'Functions.createOrUpdate' (Failed, Id=172f2590-9810-48b0-8fa7-bdb1b02b1ea6, Duration=343ms)
[2023-12-06T09:35:04.555Z]    at Microsoft.Azure.Functions.Worker.Context.Features.DefaultInputConversionFeature.ConvertAsync(ConverterContext converterContext) in D:\a\_work\1\s\src\DotNetWorker.Core\Context\Features\DefaultInputConversionFeature.cs:line 43[2023-12-06T09:35:04.556Z] System.Private.CoreLib: Exception while executing function: Functions.createOrUpdateTask. System.Private.CoreLib: Result: Failure

正确解决方案 #

启用AspNetCore集成后，[FromBody]的解析由AspNetCore输入转换管道处理，需在ConfigureFunctionsWebApplication中配置AspNetCore服务使用NewtonsoftJson，而非仅配置Worker全局序列化器：

1. 确保已安装Microsoft.AspNetCore.Mvc.NewtonsoftJson包（版本与项目.NET版本匹配，如.NET 8用8.0.x）
2. 修改Program.cs中的ConfigureFunctionsWebApplication配置：

.ConfigureFunctionsWebApplication(workerAppBuilder =>
{
    // 配置AspNetCore使用NewtonsoftJson处理请求序列化
    workerAppBuilder.Services.AddControllers().AddNewtonsoftJson(options =>
    {
        options.SerializerSettings.ContractResolver = new CamelCasePropertyNamesContractResolver();
        options.SerializerSettings.NullValueHandling = NullValueHandling.Ignore;
        // 可添加其他NewtonsoftJson配置，如日期格式、自定义转换器等
    });

    workerAppBuilder.UseWhen<AuthorizationMiddleware>(c =>
    {
        string triggerType = c.FunctionDefinition.InputBindings.Values.First(a => a.Type.EndsWith("Trigger", StringComparison.Ordinal)).Type;
        return string.Equals(triggerType, "httpTrigger", StringComparison.Ordinal);
    });
})

说明 #

• WorkerOptions.Serializer仅控制函数非HTTP绑定（如Blob、Queue等）的序列化，对[FromBody]的HTTP请求解析无效
• 使用AddControllers().AddNewtonsoftJson()是AspNetCore集成模式下的标准配置方式，符合官方设计逻辑，不存在兼容性风险

内容的提问来源于stack exchange，提问作者David P