.net core HttpClient.PutAsync返回400个错误请求（.Net Core/Blazor）

我有一个Blazor WASM应用程序和一个.NetCore 3.1 WebAPI。我通过Blazor中推荐的服务类调用我的WebAPI。然而，每次对update的PUT调用我都会返回400个错误请求。它从未到达控制器。我已经通过APITester Chrome浏览器扩展测试了API控制器，并且端点工作正常。这让我相信这是HTTPClientCall中的一些东西

这是我的控制器上的API方法

[HttpPut("{id}")]
        public async Task<IActionResult> Update(int id, [FromBody] Country country)
        {
            if (id != country.Id)
            {
                return BadRequest();
            }

            try
            {
                await _repository.UpdateAsync(id, country);
            }
            catch (DbUpdateConcurrencyException)
            {
                if (! await _repository.ExistsAsync(id))
                {
                    return NotFound();
                }
                else
                {
                    throw;
                }
            }

            return NoContent();
        }

这是我为Blazor WASM编写的Program.cs，它注册了HTTPClient

public static async Task Main(string[] args)
        {
            var builder = WebAssemblyHostBuilder.CreateDefault(args);
            builder.RootComponents.Add<App>("app");

            var baseAddress = new Uri("https://localhost:44395/api/");

            void RegisterTypedClient<TClient, TImplementation>(Uri apiBaseUrl)
                where TClient : class where TImplementation : class, TClient
            {
                builder.Services.AddHttpClient<TClient, TImplementation>(client =>
                {
                    client.BaseAddress = apiBaseUrl;
                });
            }

            RegisterTypedClient<ICountryService, CountryService>(baseAddress);          

            await builder.Build().RunAsync();
        }

公共静态异步任务主（字符串[]args）
{
var builder=WebAssemblyHostBuilder.CreateDefault（args）；
builder.RootComponents.Add（“应用程序”）；
var baseAddress=新Uri（“https://localhost:44395/api/");
无效RegisterTypedClient（Uri apiBaseUrl）
where TClient:class其中TImplementation:class，TClient
{
builder.Services.AddHttpClient（客户端=>
{
client.BaseAddress=apiBaseUrl；
});
}
RegisterTypedClient（基本地址）；
等待builder.Build（）.RunAsync（）；
}

最后，这里是WebAPI中的Startup.cs

public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            //Register EntityFramework Core Datacontext for Dependency Injection
            services.AddDbContext<DataContext>(options => options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));

            //Register Repositories for Dependency Injection
            services.AddScoped<ICountryRepository, CountryRepository>();

            services.AddCors(options =>
            {
                options.AddPolicy("Open", builder =>
                {
                    builder.AllowAnyOrigin();
                    builder.AllowAnyHeader();
                    builder.AllowAnyMethod();
                });
            });

            services.AddControllers()
                    .AddMvcOptions(o =>
                    {
                        //Allow XML as a request Accept type
                        o.OutputFormatters.Add(new XmlDataContractSerializerOutputFormatter());
                    });
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            
            app.UseHttpsRedirection();      

            app.UseRouting();

            app.UseAuthorization();

            app.UseCors("Open");

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }

公共类启动
{
公共启动（IConfiguration配置）
{
配置=配置；
}
公共IConfiguration配置{get；}
//此方法由运行时调用。请使用此方法将服务添加到容器中。
public void配置服务（IServiceCollection服务）
{
//为依赖项注入注册EntityFramework核心Datacontext
services.AddDbContext（options=>options.UseSqlServer（Configuration.GetConnectionString（“DefaultConnection”））；
//为依赖项注入注册存储库
services.addScope（）；
services.AddCors（选项=>
{
options.AddPolicy（“打开”，生成器=>
{
builder.AllowAnyOrigin（）；
builder.AllowAnyHeader（）；
builder.AllowAnyMethod（）；
});
});
services.AddControllers（）
.addmvcopions（o=>
{
//允许XML作为请求接受类型
o、 Add（新的XmlDataContractSerializerOutputFormatter（））；
});
}
//此方法由运行时调用。请使用此方法配置HTTP请求管道。
public void配置（IApplicationBuilder应用程序、IWebHostEnvironment环境）
{
if（env.IsDevelopment（））
{
app.UseDeveloperExceptionPage（）；
}
app.UseHttpsRedirection（）；
app.UseRouting（）；
app.UseAuthorization（）；
应用程序UseCors（“开放”）；
app.UseEndpoints（端点=>
{
endpoints.MapControllers（）；
});
}
}

尝试将

[HttpPut（“{id}”）]

更改为

[HttpPut，Route（{id}”）]

同样，这是错误的：

var response=wait\u httpClient.PutAsync（“Countries/{id}”，content）

您从不填写

{id}

。它应该是

var response=await\u httpClient.PutAsync（$“Countries/{id}”，content）就是这样。总是小事。谢谢你，伙计
public class Startup
    {
        public Startup(IConfiguration configuration)
        {
            Configuration = configuration;
        }

        public IConfiguration Configuration { get; }

        // This method gets called by the runtime. Use this method to add services to the container.
        public void ConfigureServices(IServiceCollection services)
        {
            //Register EntityFramework Core Datacontext for Dependency Injection
            services.AddDbContext<DataContext>(options => options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));

            //Register Repositories for Dependency Injection
            services.AddScoped<ICountryRepository, CountryRepository>();

            services.AddCors(options =>
            {
                options.AddPolicy("Open", builder =>
                {
                    builder.AllowAnyOrigin();
                    builder.AllowAnyHeader();
                    builder.AllowAnyMethod();
                });
            });

            services.AddControllers()
                    .AddMvcOptions(o =>
                    {
                        //Allow XML as a request Accept type
                        o.OutputFormatters.Add(new XmlDataContractSerializerOutputFormatter());
                    });
        }

        // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
            {
                app.UseDeveloperExceptionPage();
            }
            
            app.UseHttpsRedirection();      

            app.UseRouting();

            app.UseAuthorization();

            app.UseCors("Open");

            app.UseEndpoints(endpoints =>
            {
                endpoints.MapControllers();
            });
        }
    }