引用 AspNetCoreRateLimit => StatusCode cannot be set because the response has already started.

app.UseIpRateLimiting(); #需要放在前面，否則抓去不准，還有可能會出現下列錯誤

本次出現這個錯誤，是因為  .Net Core 跨域

里面的這行：httpContext.Response.StatusCode = 204; 由於StatusCode 先給它設了 204，所以導致 IpRateLimit 報了下圖的錯誤。

public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
{
    app.UseIpRateLimiting(); #需要放在前面 if (env.IsDevelopment())
    {
        app.UseDeveloperExceptionPage();
    }
    else
    {
        app.UseExceptionHandler("/Home/Error");
        app.UseStatusCodePagesWithReExecute("/Home/Error");
    }
    
    //..............
}

app.UseIpRateLimiting(); #需要放在前面，否則抓去不准，還有可能會出現下列錯誤

 

 

 

fail: Microsoft.AspNetCore.Server.Kestrel[13]
      Connection id "0HM084E4TPLBN", Request id "0HM084E4TPLBN:00000001": An unhandled exception was thrown by the application.
System.InvalidOperationException: StatusCode cannot be set because the response has already started.
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ThrowResponseAlreadyStartedException(String value)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.set_StatusCode(Int32 value)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.Microsoft.AspNetCore.Http.Features.IHttpResponseFeature.set_StatusCode(Int32 value)
   at Microsoft.AspNetCore.Http.DefaultHttpResponse.set_StatusCode(Int32 value)
   at Microsoft.AspNetCore.Routing.Matching.HttpMethodMatcherPolicy.<>c__DisplayClass15_0.<CreateRejectionEndpoint>b__0(HttpContext context)
   at Microsoft.AspNetCore.Routing.EndpointMiddleware.Invoke(HttpContext httpContext)
--- End of stack trace from previous location where exception was thrown ---
   at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Session.SessionMiddleware.Invoke(HttpContext context)
   at AspNetCoreRateLimit.RateLimitMiddleware`1.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Diagnostics.StatusCodePagesMiddleware.Invoke(HttpContext context)
   at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.<Invoke>g__Awaited|6_0(ExceptionHandlerMiddleware middleware, HttpContext context, Task task)
   at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.HandleException(HttpContext context, ExceptionDispatchInfo edi)
   at Microsoft.AspNetCore.Diagnostics.ExceptionHandlerMiddleware.<Invoke>g__Awaited|6_0(ExceptionHandlerMiddleware middleware, HttpContext context, Task task)
   at Microsoft.AspNetCore.Server.Kestrel.Core.Internal.Http.HttpProtocol.ProcessRequests[TContext](IHttpApplication`1 application)