我正在尝试在我的ASP上启用跨起源资源共享。NET核心Web API,但我卡住了。

EnableCors属性接受字符串类型的policyName作为参数:

// Summary:
//     Creates a new instance of the Microsoft.AspNetCore.Cors.Core.EnableCorsAttribute.
//
// Parameters:
//   policyName:
//     The name of the policy to be applied.
public EnableCorsAttribute(string policyName);

policyName是什么意思,如何在ASP上配置CORS。NET核心Web API?


当前回答

适用于。net Core 1和。net Core 2

如果使用.Net-Core 1.1

不幸的是,在这个特定的情况下,文件非常混乱。所以我要让它变得非常简单:

将Microsoft.AspNetCore.Cors nuget包添加到项目中 在ConfigureServices方法中添加services.AddCors(); 在Configure方法中,在调用app.UseMvc()和app.UseStaticFiles()之前,添加: app.UseCors(生成器=>生成器 .AllowAnyOrigin () .AllowAnyMethod () .AllowAnyHeader () .AllowCredentials ());

就是这样。每个客户端都可以访问您的ASP。NET核心网站/API。


如果使用。net - core 2.0

Add Microsoft.AspNetCore.Cors nuget package to your project in ConfigureServices method, before calling services.AddMvc(), add: services.AddCors(options => { options.AddPolicy("AllowAll", builder => { builder .AllowAnyOrigin() .AllowAnyMethod() .AllowAnyHeader() .AllowCredentials(); }); }); (Important) In Configure method, before calling app.UseMvc(), add app.UseCors("AllowAll"); "AllowAll" is the policy name which we need to mention in app.UseCors. It could be any name.

其他回答

得到这个工作与。net Core 3.1如下:

在ConfigureServices()方法中:

 public void ConfigureServices(IServiceCollection services)
  {
   ...
   services.AddCors();
   ...
  }

在Configure()方法中:

 public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
  {
   ...
   app.UseCors(builder =>
          builder.AllowAnyOrigin()
          .AllowAnyHeader()
          .AllowAnyMethod()
        );
   ...
  }

你有三种方式启用CORS:

在中间件中使用命名策略或默认策略。 使用端点路由。 使用[EnableCors]属性。

启用指定策略的CORS:

public class Startup
{
    readonly string CorsPolicy = "_corsPolicy";

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddCors(options =>
        {
            options.AddPolicy(name: CorsPolicy,
                              builder =>
                              {
                                 builder.AllowAnyOrigin()
                                      .AllowAnyMethod()
                                      .AllowAnyHeader()
                                      .AllowCredentials();
                              });
        });

        // services.AddResponseCaching();
        services.AddControllers();
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        app.UseRouting();

        app.UseCors(CorsPolicy);

        // app.UseResponseCaching();

        app.UseAuthorization();

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

当使用UseResponseCaching时,UseCors必须在UseResponseCaching之前调用。

开启默认策略下的CORS:

public class Startup
{
    public void ConfigureServices(IServiceCollection services)
    {
        services.AddCors(options =>
        {
            options.AddDefaultPolicy(
                builder =>
                {
                     builder.AllowAnyOrigin()
                                      .AllowAnyMethod()
                                      .AllowAnyHeader()
                                      .AllowCredentials();
                });
        });

        services.AddControllers();
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        app.UseRouting();

        app.UseCors();

        app.UseAuthorization();

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

启用带有端点的CORS

public class Startup
{
    readonly string CorsPolicy = "_corsPolicy ";

    public void ConfigureServices(IServiceCollection services)
    {
        services.AddCors(options =>
        {
            options.AddPolicy(name: CorsPolicy,
                              builder =>
                              {
                                  builder.AllowAnyOrigin()
                                      .AllowAnyMethod()
                                      .AllowAnyHeader()
                                      .AllowCredentials();
                              });
        });

        services.AddControllers();
    }

    public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
    {
        app.UseRouting();

        app.UseCors();

        app.UseAuthorization();

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

启用带有属性的CORS

你有两个选择

[EnableCors]默认策略。 [EnableCors("{Policy String}")]指定命名策略。

得到这个工作与。net Core 3.1如下

确保你把UseCors代码放在app.UseRouting()之间;和app.UseAuthentication ();

app.UseHttpsRedirection();

app.UseRouting();
app.UseCors("CorsApi");

app.UseAuthentication();
app.UseAuthorization();

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

然后将此代码放在ConfigureServices方法中

services.AddCors(options =>
{
    options.AddPolicy("CorsApi",
        builder => builder.WithOrigins("http://localhost:4200", "http://mywebsite.com")
            .AllowAnyHeader()
            .AllowAnyMethod());
});

在基本控制器上面我放了这个

[EnableCors("CorsApi")]
[Route("api/[controller]")]
[ApiController]
public class BaseController : ControllerBase

现在我所有的控制器都将继承BaseController,并启用CORS

对于Web API(ASP。Net core 6.0) 在Program.cs中,只需在builder.Build()之前添加;

builder.Services.AddCors(p => p.AddPolicy("corsapp", builder =>
{
    builder.WithOrigins("*").AllowAnyMethod().AllowAnyHeader();
}));

也添加

app.UseCors("corsapp");

ASP。NET Core 6:

var  MyAllowSpecificOrigins = "_myAllowSpecificOrigins";

var builder = WebApplication.CreateBuilder(args);

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

// services.AddResponseCaching();

builder.Services.AddControllers();

var app = builder.Build();
app.UseHttpsRedirection();
app.UseStaticFiles();
app.UseRouting();

app.UseCors(MyAllowSpecificOrigins);

app.UseAuthorization();

app.MapControllers();

app.Run();

更多样品请参考官方文档。


ASP。NET Core 3.1和5.0:

你必须在应用程序启动时在ConfigureServices方法中配置CORS策略:

public void ConfigureServices(IServiceCollection services)
{
    services.AddCors(o => o.AddPolicy("MyPolicy", builder =>
    {
        builder.WithOrigins("http://example.com")
               .AllowAnyMethod()
               .AllowAnyHeader();
    }));

    // ...
}

builder中的CorsPolicyBuilder允许您根据需要配置策略。你现在可以使用这个名字将策略应用到控制器和动作上:

[EnableCors("MyPolicy")]

或者把它应用到每一个请求上:

public void Configure(IApplicationBuilder app)
{
    app.UseCors("MyPolicy");

    // ...

    // This should always be called last to ensure that
    // middleware is registered in the correct order.
    app.UseMvc();
}