ASP.NET Core 8 Cors 标头未显示

Question

我在让 Cors 在 ASP.NET Core 8 Minimal API 项目上运行时遇到了意外问题。我设置了一个测试项目，只是使用模板来启动并运行它，然后添加了我认为应该显示 Cors 内容的内容，但我没有任何运气。

var builder = WebApplication.CreateBuilder(args);
const string MyAllowSpecificOrigins = "_myAllowSpecificOrigins";
// Add services to the container.
// Learn more about configuring Swagger/OpenAPI at https://aka.ms/aspnetcore/swashbuckle
builder.Services.AddEndpointsApiExplorer();
builder.Services.AddSwaggerGen();

builder.Services.AddCors(options =>
{
    options.AddPolicy(name: MyAllowSpecificOrigins,
        builder =>
        {
            builder.WithOrigins("http://example.com",
                "http://www.contoso.com");
        });
});

var app = builder.Build();

// Configure the HTTP request pipeline.
if (app.Environment.IsDevelopment()) {
    app.UseSwagger();
    app.UseSwaggerUI();
}

app.UseHttpsRedirection();

app.UseCors();

var summaries = new[]
{
    "Freezing", "Bracing", "Chilly", "Cool", "Mild", "Warm", "Balmy", "Hot", "Sweltering", "Scorching"
};

app.MapGet("/weatherforecast", () =>
    {
        var forecast = Enumerable.Range(1, 5).Select(index =>
                new WeatherForecast
                (
                    DateOnly.FromDateTime(DateTime.Now.AddDays(index)),
                    Random.Shared.Next(-20, 55),
                    summaries[Random.Shared.Next(summaries.Length)]
                ))
            .ToArray();
        return forecast;
    })
    .WithName("GetWeatherForecast")
    .WithOpenApi();

app.Run();

record WeatherForecast(DateOnly Date, int TemperatureC, string? Summary) {
    public int TemperatureF => 32 + (int)(TemperatureC / 0.5556);
}

然后我这样称呼它：

curl -vkX 'GET'   'https://localhost:8005/weatherforecast'   -H 'accept: application/json'

并得到这个：

HTTP/2 200   
content-type: application/json; charset=utf-8  
date: Sat, 27 Apr 2024 17:45:49 GMT  
server: Kestrel  
  
Connection #0 to host localhost left intact
[
    { "date": "2024-04-28", "temperatureC": 25,"summary": "Balmy", "temperatureF": 76 },
    { "date": "2024-04-29", "temperatureC": 37,"summary": "Mild", "temperatureF": 98 },
    { "date": "2024-04-30", "temperatureC": 9,"summary": "Cool", "temperatureF": 48 },
    { "date": "2024-05-01", "temperatureC": 10,"summary": "Chilly", "temperatureF": 49 },
    { "date": "2024-05-02", "temperatureC": 17,"summary": "Mild", "temperatureF": 62 }
]

（我确实编辑了握手信息）

我希望在标题中看到 cors 标题，但正如您所看到的，它不在那里。我错过了什么？

也不确定这是否有什么不同，但我是从 Docker 容器运行的。

Answer 1

尝试添加 RequireCors(MyAllowSpecificOrigins)

app.MapGet("/weatherforecast", () =>
{
    var forecast = Enumerable.Range(1, 5).Select(index =>
            new WeatherForecast
            (
                DateOnly.FromDateTime(DateTime.Now.AddDays(index)),
                Random.Shared.Next(-20, 55),
                summaries[Random.Shared.Next(summaries.Length)]
            ))
        .ToArray();
    return forecast;
})
.WithName("GetWeatherForecast")
.WithOpenApi()
.RequireCors(MyAllowSpecificOrigins);