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[정성태] 아쉽게도, 커뮤니티는 아니고 개인 블로그입니다. ^^
[정성태] 질문이 잘 이해가 안 됩니다. 우선, 해당 소스코드에서 ILis...
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] var대신 dinamic으로 선언해서 해결은 했습니다. 맞는 해...
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[정성태] "props[i].GetValue(props[i])" 코드에서 ...
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[정성태] Modules 창(Ctrl+Shift+U)을 띄워서, 해당 Op...
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<div style='display: inline'> <h1 style='font-family: Malgun Gothic, Consolas; font-size: 20pt; color: #006699; text-align: center; font-weight: bold'>C# - ASP.NET Core 웹 응용 프로그램의 출력 가로채기</h1> <p> 지난 글에서 다룬 ASP.NET 웹 응용 프로그램에 대한 가로채기 방식은,<br /> <br /> <pre style='margin: 10px 0px 10px 10px; padding: 10px 0px 10px 10px; background-color: #fbedbb; overflow: auto; font-family: Consolas, Verdana;' > C# - ASP.NET 웹 응용 프로그램의 출력 가로채기 ; <a target='tab' href='https://www.sysnet.pe.kr/2/0/12140'>https://www.sysnet.pe.kr/2/0/12140</a> </pre> <br /> ASP.NET Core에서는 구조 자체가 바뀌기 때문에 적용할 수 없습니다. 단지, FilterStream 클래스는 거의 그대로 재사용할 수 있는데 대신 다음과 같이 WriteAsync를 하나 더 추가해야 합니다.<br /> <br /> <pre style='margin: 10px 0px 10px 10px; padding: 10px 0px 10px 10px; background-color: #fbedbb; overflow: auto; font-family: Consolas, Verdana;' > public override void Write(byte[] buffer, int offset, int count) { _orginalStream.Write(buffer, offset, count); } <span style='color: blue; font-weight: bold'>public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken) { await _orginalStream.WriteAsync(buffer, offset, count, cancellationToken); }</span> </pre> <br /> 마찬가지로 다음과 같은 식으로 구현하면 HTTP 출력의 chunk마다,<br /> <br /> <pre style='margin: 10px 0px 10px 10px; padding: 10px 0px 10px 10px; background-color: #fbedbb; overflow: auto; font-family: Consolas, Verdana;' > public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken) { await _orginalStream.WriteAsync(buffer, offset, count, cancellationToken); <span style='color: blue; font-weight: bold'>byte[] buf = _encoding.GetBytes("TEST"); await _orginalStream.WriteAsync(buf, 0, buf.Length, cancellationToken);</span> } </pre> <br /> 마지막에 "TEST" 문자열을 덧붙이게 됩니다. 또한, 이렇게 만든 Stream 타입을 기존 출력에 연결하려면 이것을 담당하는 middleware 타입을 하나 만들고,<br /> <br /> <pre style='margin: 10px 0px 10px 10px; padding: 10px 0px 10px 10px; background-color: #fbedbb; overflow: auto; font-family: Consolas, Verdana;' > public class HttpResponseFilter { Microsoft.AspNetCore.Http.RequestDelegate _next; public HttpResponseFilter(Microsoft.AspNetCore.Http.RequestDelegate next) { _next = next; } public async Task Invoke(Microsoft.AspNetCore.Http.HttpContext context) { <span style='color: blue; font-weight: bold'>context.Response.Body = new FilterStream(context.Response.Body, Encoding.UTF8);</span> await _next.Invoke(context); } } </pre> <br /> ASP.NET Core에 연결해 주면 됩니다. (또는 그냥 Middleware 없이 Use 확장 메서드를 이용해 단순 익명 함수로 연결해도 됩니다.)<br /> <br /> <pre style='margin: 10px 0px 10px 10px; padding: 10px 0px 10px 10px; background-color: #fbedbb; overflow: auto; font-family: Consolas, Verdana;' > public void Configure(IApplicationBuilder app, IWebHostEnvironment env) { if (env.IsDevelopment()) { app.UseDeveloperExceptionPage(); } else { app.UseExceptionHandler("/Error"); // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts. app.UseHsts(); } <span style='color: blue; font-weight: bold'>app.UseMiddleware<HttpResponseFilter>();</span> app.UseHttpsRedirection(); app.UseStaticFiles(); app.UseRouting(); app.UseAuthorization(); app.UseEndpoints(endpoints => { endpoints.MapRazorPages(); }); } </pre> <br /> 이후 다음과 같은 식의 razor 페이지가 실행될 때마다,<br /> <br /> <pre style='margin: 10px 0px 10px 10px; padding: 10px 0px 10px 10px; background-color: #fbedbb; overflow: auto; font-family: Consolas, Verdana;' > @page @model IndexModel @{ ViewData["Title"] = "Home page"; } <div class="text-center"> <h1 class="display-4">Welcome</h1> <p>Learn about <a href="https://docs.microsoft.com/aspnet/core">building Web apps with ASP.NET Core</a>.</p> </div> </pre> <br /> 출력 결과는 "TEST" 문자열이 추가되는 방식으로 동작합니다.<br /> <br /> <pre style='margin: 10px 0px 10px 10px; padding: 10px 0px 10px 10px; background-color: #fbedbb; overflow: auto; font-family: Consolas, Verdana;' > <!DOCTYPE html> <html lang="en"> <head> <meta charset="utf-8" /> <meta name="viewport" content="width=device-width, initial-scale=1.0" /> <title>Home page - WebApplication1</title> <link rel="stylesheet" href="/lib/bootstrap/dist/css/bootstrap.min.css" /> <link rel="stylesheet" href="/css/site.css" /> </head> <body> <header> <nav class="navbar navbar-expand-sm navbar-toggleable-sm navbar-light bg-white border-bottom box-shadow mb-3"> <div class="container"> <a class="navbar-brand" href="/">WebApplication1</a> <button class="navbar-toggler" type="button" data-toggle="collapse" data-target=".navbar-collapse" aria-controls="navbarSupportedContent" aria-expanded="false" aria-label="Toggle navigation"> <span class="navbar-toggler-icon"></span> </button> <div class="navbar-collapse collapse d-sm-inline-flex flex-sm-row-reverse"> <ul class="navbar-nav flex-grow-1"> <li class="nav-item"> <a class="nav-link text-dark" href="/">Home</a> </li> <li class="nav-item"> <a class="nav-link text-dark" href="/Privacy">Privacy</a> </li> </ul> </div> </div> </nav> </header> <div class="container"> <main role="main" class="pb-3"> <div class="text-center"> <h1 class="display-4">Welcome</h1> <p>Learn about <a href="https://docs.microsoft.com/aspnet/core">building Web apps with ASP.NET Core</a>.</p> </div> </main> </div> <footer class="border-top footer text-muted"> <div class="container"> &copy; 2020 - WebApplication1 - <a href="/Privacy">Privacy</a> </div> </footer> <script src="/lib/jquery/dist/jquery.min.js"></script> <script src="/lib/bootstrap/dist/js/bootstrap.bundle.min.js"></script> <script src="/js/site.js?v=dLGP40S79Xnx6GqUthRF6NWvjvhQ1nOvdVSwaNcgG18"></script> </body> </html> <span style='color: blue; font-weight: bold'>TEST</span> </pre> <br /> 결국 실제 가로채기를 담당하는 FilterStream 타입의 구현은 변함이 없지만, 한 가지 아쉬운 점이 있다면 "Response.Encoding" 타입을 ASP.NET Core의 Middleware 수준에서는 알 수 없다는 점입니다. 이로 인해 가로채기한 출력 결과물의 byte []를 어떤 유형의 디코딩 방식을 적용해야 하는지 알 수 없는 문제가 있습니다. (현실적으로 대개의 경우 Encoding.UTF8이겠지만!)<br /> <br /> (<a target='tab' href='https://www.sysnet.pe.kr/bbs/DownloadAttachment.aspx?fid=1550&boardid=331301885'>첨부 파일은 이 글의 예제 코드를 포함</a>합니다.)<br /> <br /> <hr style='width: 50%' /><br /> <br /> 참고로, ASP.NET Core의 Stream을 대체한 타입이 WriteAsync 메서드를 구현하지 않으면,<br /> <br /> <pre style='margin: 10px 0px 10px 10px; padding: 10px 0px 10px 10px; background-color: #fbedbb; overflow: auto; font-family: Consolas, Verdana;' > public override void Write(byte[] buffer, int offset, int count) { _orginalStream.Write(buffer, offset, count); } //public override async Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken) //{ // await _orginalStream.WriteAsync(buffer, offset, count, cancellationToken); //} </pre> <br /> Write 동기 메서드가 실행이 되긴 합니다. 하지만 _orginalStream.Write 시점에 다음과 같은 식의 예외가 발생하는 것을 볼 수 있습니다.<br /> <br /> <pre style='margin: 10px 0px 10px 10px; padding: 10px 0px 10px 10px; background-color: #fbedbb; overflow: auto; font-family: Consolas, Verdana;' > Exception thrown: 'System.InvalidOperationException' in Microsoft.AspNetCore.Server.IIS.dll Exception thrown: 'System.InvalidOperationException' in System.Private.CoreLib.dll Exception thrown: 'System.InvalidOperationException' in System.Private.CoreLib.dll Exception thrown: 'System.InvalidOperationException' in System.Private.CoreLib.dll Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware: Error: An exception was thrown attempting to display the error page. System.InvalidOperationException: Synchronous operations are disallowed. Call WriteAsync or set AllowSynchronousIO to true instead. at Microsoft.AspNetCore.Server.IIS.Core.HttpResponseStream.Write(Byte[] buffer, Int32 offset, Int32 count) at Microsoft.AspNetCore.Server.IIS.Core.WrappingStream.Write(Byte[] buffer, Int32 offset, Int32 count) at WebApplication1.FilterStream.Write(Byte[] buffer, Int32 offset, Int32 count) in C:\WebApplication1\WebApplication1\FilterStream.cs:line 55 at System.IO.Stream.<>c.<BeginWriteInternal>b__51_0(Object <p0>) at System.Threading.Tasks.Task`1.InnerInvoke() at System.Threading.Tasks.Task.<>c.<.cctor>b__274_0(Object obj) at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state) --- End of stack trace from previous location where exception was thrown --- at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread) --- End of stack trace from previous location where exception was thrown --- at Microsoft.Extensions.RazorViews.BaseView.ExecuteAsync(HttpContext context) at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context) Exception thrown: 'System.InvalidOperationException' in System.Private.CoreLib.dll Exception thrown: 'System.InvalidOperationException' in System.Private.CoreLib.dll Microsoft.AspNetCore.Server.IIS.Core.IISHttpServer: Error: Connection ID "18230571301796315140", Request ID "80000005-0002-fd00-b63f-84710c7967bb": An unhandled exception was thrown by the application. System.InvalidOperationException: Synchronous operations are disallowed. Call WriteAsync or set AllowSynchronousIO to true instead. at Microsoft.AspNetCore.Server.IIS.Core.HttpResponseStream.Write(Byte[] buffer, Int32 offset, Int32 count) at Microsoft.AspNetCore.Server.IIS.Core.WrappingStream.Write(Byte[] buffer, Int32 offset, Int32 count) at WebApplication1.FilterStream.Write(Byte[] buffer, Int32 offset, Int32 count) in C:\WebApplication1\WebApplication1\FilterStream.cs:line 55 at System.IO.Stream.<>c.<BeginWriteInternal>b__51_0(Object <p0>) at System.Threading.Tasks.Task`1.InnerInvoke() at System.Threading.Tasks.Task.<>c.<.cctor>b__274_0(Object obj) at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state) --- End of stack trace from previous location where exception was thrown --- at System.Threading.ExecutionContext.RunFromThreadPoolDispatchLoop(Thread threadPoolThread, ExecutionContext executionContext, ContextCallback callback, Object state) at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot, Thread threadPoolThread) --- End of stack trace from previous location where exception was thrown --- at Microsoft.AspNetCore.WebUtilities.HttpResponseStreamWriter.FlushInternalAsync(Boolean flushEncoder) at Microsoft.AspNetCore.Mvc.ViewFeatures.ViewExecutor.ExecuteAsync(ViewContext viewContext, String contentType, Nullable`1 statusCode) at Microsoft.AspNetCore.Mvc.ViewFeatures.ViewExecutor.ExecuteAsync(ViewContext viewContext, String contentType, Nullable`1 statusCode) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeResultAsync>g__Logged|21_0(ResourceInvoker invoker, IActionResult result) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResultFilterAsync>g__Awaited|29_0[TFilter,TFilterAsync](ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResultExecutedContextSealed context) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.ResultNext[TFilter,TFilterAsync](State& next, Scope& scope, Object& state, Boolean& isCompleted) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeResultFilters>g__Awaited|27_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeNextResourceFilter>g__Awaited|24_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Rethrow(ResourceExecutedContextSealed context) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.Next(State& next, Scope& scope, Object& state, Boolean& isCompleted) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeFilterPipelineAsync>g__Awaited|19_0(ResourceInvoker invoker, Task lastTask, State next, Scope scope, Object state, Boolean isCompleted) at Microsoft.AspNetCore.Mvc.Infrastructure.ResourceInvoker.<InvokeAsync>g__Logged|17_1(ResourceInvoker invoker) at Microsoft.AspNetCore.Routing.EndpointMiddleware.<Invoke>g__AwaitRequestTask|6_0(Endpoint endpoint, Task requestTask, ILogger logger) at Microsoft.AspNetCore.Authorization.AuthorizationMiddleware.Invoke(HttpContext context) at WebApplication1.HttpResponseFilter.Invoke(HttpContext context) in C:\WebApplication1\WebApplication1\HttpResponseFilter.cs:line 20 at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.Diagnostics.DeveloperExceptionPageMiddleware.Invoke(HttpContext context) at Microsoft.AspNetCore.Server.IIS.Core.IISHttpContextOfT`1.ProcessRequestAsync() </pre> </p><br /> <br /><hr /><span style='color: Maroon'>[이 글에 대해서 여러분들과 의견을 공유하고 싶습니다. 틀리거나 미흡한 부분 또는 의문 사항이 있으시면 언제든 댓글 남겨주십시오.]</span> </div>
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