c# - 如何在 ASP.NET Core 3.1 中获取当前的 JsonSerializerOptions？

Question

我使用 System.Text.Json 并在 Startup.cs 的 ConfigureServices 方法中设置 JsonSerializerOptions

 public void ConfigureServices(IServiceCollection services)
 { 
 ...
            services.AddControllers()
                    .AddJsonOptions(options =>
                    {
                        options.JsonSerializerOptions.PropertyNamingPolicy = JsonNamingPolicy.CamelCase;
                    });
 ...
 }

现在我想在 CustomErrorHandlingMiddleware 中获取当前的 JsonSerializerOptions

public async Task InvokeAsync(HttpContext context)
{
      try
      {
          await _next(context);
      }
      catch (Exception exc)
      {
          var response = new SomeObject(); 
                
          var currentJsonSerializerOptions = ? //I want get CurrentJsonSerializerOptions here

          var result = System.Text.Json.JsonSerializer.Serialize(response, currentJsonSerializerOptions);

          context.Response.ContentType = "application/json";
          context.Response.StatusCode = 500;
          await context.Response.WriteAsync(result);
      }
}

我怎样才能做到这一点？谢谢。

Answer 1

你可以注入(inject) IOptions<JsonOptions>或 IOptionsSnapshot<JsonOptions>根据 Options pattern进入你的中间件。

public async Task Invoke(HttpContext httpContext, IOptions<JsonOptions> options)
{
    JsonSerializerOptions serializerOptions = options.Value.JsonSerializerOptions;

    await _next(httpContext);
}