Response.Flush() throws System.Web.HttpException
asp.net, c#, httphandler, image
Solution
While I agree with Mitchel - there's little need to call flush as you're about to call End, if you're using this elsewhere, you could try calling `Response.IsClientConnnected` first.
Gets a value indicating whether the client is still connected to the server.
Problem
I have a HttpHandler that I'm using to handle certain images on a client's website. When I'm outputting the image stream to the response object and call Flush occasionally an error is thrown. Here is a codeblock ``` var image = Image.FromStream(memStream); if (size > -1) image = ImageResize.ResizeImage(image, size, size, false); if (height > -1) image = ImageResize.Crop(image, size, height, ImageResize.AnchorPosition.Center); context.Response.Clear(); context.Response.ContentType = contentType; context.Response.BufferOutput = true; image.Save(context.Response.OutputStream, ImageFormat.Jpeg); context.Response.Flush(); context.Response.End(); ``` From what I've read, this exception is caused by a client disconnecting before the process has completed and there is nothing to flush. Here is an output of my error page ``` System.Web.HttpException: An error occurred while communicating with the remote host. The error code is 0x80070057. Generated: Mon, 12 Oct 2009 03:18:24 GMT System.Web.HttpException: An error occurred while communicating with the remote host. The error code is 0x80070057. at System.Web.Hosting.ISAPIWorkerRequestInProcForIIS6.FlushCore(Byte[] status, Byte[] header, Int32 keepConnected, Int32 totalBodySize, Int32 numBodyFragments, IntPtr[] bodyFragments, Int32[] bodyFragmentLengths, Int32 doneWithSession, Int32 finalStatus, Boolean& async) at System.Web.Hosting.ISAPIWorkerRequest.FlushCachedResponse(Boolean isFinal) at System.Web.Hosting.ISAPIWorkerRequest.FlushResponse(Boolean finalFlush) at System.Web.HttpResponse.Flush(Boolean finalFlush) at System.Web.HttpResponse.Flush() at PineBluff.Core.ImageHandler.ProcessRequest(HttpContext context) in c:\TeamCity\buildAgent\work\79b3c57a060ff42d\src\PineBluff.Core\ImageHandler.cs:line 75 at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) ``` context.Response.Flush falls at line 75. Is there a way to check this before performing the flush without wrapping it in a try/catch block.?