Examine WebResponse Without Affecting The Underlying Response Stream In .NET?
Oct 27, 2010
After a call to initial HttpWebResponse.GetResponseStream() and reading through the stream, that stream is done for and cannot be reused.
I have a situation where I need to examine the content of the response and if it is of a certain data, get another page and then pass the new response down the line. Otherwise, pass down the original response as is. The only problem is that after examining the response to check for this "special data", that response is no good to the downstream code.
The only way, I can think of, to make this transparent to the downstream code, is to create a derived class of HttpWebResponse, and somehow cache the data streamed, and pass that cached stream down the line instead of the initial stream. I'm not sure if that's even feasible since I haven't looked into it further.
I have an excel file in my Response Output stream. I can Open the stream as a file after a prompt, but it doesn't seem I can save it directly to a specified folder on my client.
I'm trying to return an xml string from a IHttpHandler to a like this: context.Response.Write(xml); When I receive the response in my .aspx.cs I try to load the document as follows: var xml = XDocument.Load(xmlString); but I get an Illegal Characters in Path error message. I've also tried
in previously asked question answeres said they dont get what i want to do exactly so heres is the full code also i simply want that instead of a TABLESe i rendered an image( of the content ) on the page
using System; using System.Collections.Generic; using System.Linq; using System.Web; using System.Web.UI; using System.IO; using System.Text; using System.Data; using System.Drawing; public partial class _Default : System.Web.UI.Page { protected void Page_Load(object sender, EventArgs e) { System.Web.UI.WebControls.Panel panelmain = new System.Web.UI.WebControls.Panel(); System.Web.UI.WebControls.Literal abc = new System.Web.UI.WebControls.Literal(); abc.Text = "as<br/>dasdas<br/>dasdad"; DataSet ds = new DataSet(); DataTable dt; DataRow dr; DataColumn idCoulumn; DataColumn nameCoulumn; dt = new DataTable(); idCoulumn = new DataColumn("ID", Type.GetType("System.Int32")); nameCoulumn = new DataColumn("Name", Type.GetType("System.String")); dt.Columns.Add(idCoulumn); dt.Columns.Add(nameCoulumn); dr = dt.NewRow(); dr["ID"] = 1; dr["Name"] = "Name1"; dt.Rows.Add(dr); dr = dt.NewRow(); dr["ID"] = 2;.............
MemoryStream export = new MemoryStream(); iCalendarSerializer serializer = new iCalendarSerializer(iCal); serializer.Serialize(export,System.Text.Encoding.UTF8); return export;
so I am using the C# DDay.iCal library for exporting my calendars. Serialize takes in a "stream" so I passed it a memory stream. I now have a generic handler that calls the method that contains the above code.
public class CalendarHandler : IHttpHandler { private Calendar service; private Membership membershipS; public void ProcessRequest(HttpContext context) { service = new Calendar (); membershipS = new Membership (null); string userName = context.User.Identity.Name; Guid userId = membershipS.GetUsersId(userName); context.Response.ContentType = "text/calendar"; // calls the export calendar(the code that showed above that uses dDay ical. var t = service.ExportCalendar(userId); t.WriteTo(context.Response.OutputStream); } public bool IsReusable { get { return false; } } }
So now I wrote the icalendar to the Outputstream. Now I have a jquery post that goes to this method and now I am not sure how to take the OutputStream result that the jquery post will get and make it popup with a save dialog box.
I created a simple Http Module that starts a timer on the PreRequestHandler and stops the timer on the PostRequestHandler to calculate the time it took the page to load. I then create some simple html and write my results to Response.Write. Since I'm doing this in the PostRequestHandler it's adding my results after the </html> tag. That's fine for testing but I need in a scenario where the page needs to validate.
I can't seem to figure out how I could manipulate the Response object to insert my results before the </body> tag. Response.Write and Response.Output.Write don't have that flexibility and I couldn't see a way to work with the Response as a string. Am I missing something easy?
We're getting this weird exception when trying to create a BitmapDecoder off an ASP.Net response stream. This is the line of code that throws the exception:
BitmapDecoder dec = BitmapDecoder.Create( Request.Files[0].InputStream, BitmapCreateOptions.PreservePixelFormat, BitmapCacheOption.OnLoad);
Here's some info on the file being uploaded: Filename: bank statement.jpg, Content length: 266041, Mime type: image/jpeg
This is the exception stack trace:
System.IO.IOException: Cannot read from the stream. ---> System.Runtime.InteropServices.COMException (0x88982F72): Exception from HRESULT: 0x88982F72 [code]...
Is is possible to update an image on an HTML page using the response stream of an ASP.NET Generic Handler? For example, if I have the following code on a handler: [URL]
How can I call the handler in jQuery, using .ajax, and set an image on the page equal to the image that is returned by the Handler? I am ignoring the query string variable at the moment as I just want to get this working. Secondly, if I can do above, how can I loop through all of DIVs on the page that are of class "content", select a guid out of a hidden field to use as my query string parameter, and update the associated image within the same content DIV tag? A content div tag would look as follows:
I would like to have all the images updated on a periodic interval, so essentially, as a quick recap, I would need to have: A loop through all of my DIVs of class "content", occuring every n. seconds. Extractation the GUID from the hidden field. A call to my ASHX handler to get the updated image. Set the returned image to the corrisponding image on the page. Is this something that would be difficult to achieve? If not, what would I need to do to make this function in the above manner?
Is is possible to write to the http response stream from a dynamically created bitmap using the Response.Write/WriteFile without saving the image to the hard drive?
I'm using .net 3.5 and am currently creating a web application used to generate a report through Aspose.CellsActually, the page is composed in a form where I get the configuration of the report I have to generate. The "generation" button is in an update panel. When I click on it, the "generation" button is hidden and a progress bar appears. When the excel file is generated, I save it in a memory stream and I send it back to the aspx page where I change the headers to allow the file's download.
I am trying to use a custom ITempDataProvider provider to store TempData in a browser's cookie instead of session state. However, everything works fine except that I am unable to remove the cookie from the Response stream after reading it. The code exexutes fine but the cookie won't go away.
I'm using Filestream for read big file (> 500 MB) and I get the OutOfMemoryException. Any solutions about it?? I want this in my app asp.net: Read DATA from Oracle Uncompress file using FileStream and BZip2 Read file uncompressed and send it to asp.net page for download. When I read file from disk, Fails !!! and get OutOfMemory. My Code is:
using (var fs3 = new FileStream(filePath2, FileMode.Open, FileAccess.Read)) { byte[] b2 = ReadFully(fs3, 1024); } // [URL] public static byte[] ReadFully(Stream stream, int initialLength) { // If we've been passed an unhelpful initial length, just // use 32K. if (initialLength < 1) { initialLength = 32768; } byte[] buffer = new byte[initialLength]; int read = 0; int chunk; while ((chunk = stream.Read(buffer, read, buffer.Length - read)) > 0) { read += chunk; // If we've reached the end of our buffer, check to see if there's // any more information if (read == buffer.Length) { int nextByte = stream.ReadByte(); // End of stream? If so, we're done if (nextByte == -1)............................
I have an httpmodule and it has a handler for OnEndRequest. I am trying to write the HttpContext.Response.OutputStream to a file. I am trying to use the Read method of it. But when it is called the exception message i get is "Specified method is not supported". So i am not able to do what i want that is, write the response to a file on the disk. I am able to write the HttpContext.Request.InputStream to a file using its Read method which i do in a handler for OnBeginRequest.
I am generating an Excel file upon a click of a button in an update panel. It is throwing a parsing error.
If I keep the button outside the update panel it is working fine. Why isn't it working in the update Panel?
Response.ContentType = "application/vnd.ms-excel" Response.AddHeader("Content-Disposition", String.Format("attachment;filename={0}", filename)) Response.Clear() Response.BinaryWrite(WriteToStream.GetBuffer) HttpContext.Current.ApplicationInstance.CompleteRequest() Private Function WriteToStream() As MemoryStream 'Write the stream data of workbook to the root directory Dim file As MemoryStream = New MemoryStream hssfworkbook.Write(file) Return file End Function
I need to to export a file to the user. It takes 1-2 min to generate the file so I'd like to have the page go into a kind-of modal mode with a layover on the page and a 'Working' spinner showing. The problem is I can't make the modal stuff go away after Save File dialog is closed.
How can I remove the layover after the dialog is done?
I have an ASP.NET FileUpload control, which allows only image type. I used RegularExpressionValidator like below.
<asp:FileUpload ID="fuPhoto" runat="server" TabIndex="40" /> <asp:RegularExpressionValidator ID="RegularExpressionValidator3" runat="server" ControlToValidate="fuPhoto" Display="Dynamic" ErrorMessage="* You can only upload .jpg, .gif or .png image types." ValidationExpression="^.*.(jpg|JPG|jpeg|JPEG|gif|GIF|png|PNG)$">* You can only upload .jpg, .gif or .png image types.</asp:RegularExpressionValidator>
This method will only verify the file's extension, not its actual type. Once I receive the file, I want to examine its contents to determine what it really is, in this case image only.
I have built a simple threadpool based web crawler within my web application. Its job is to crawl its own application space and build a Lucene index of every valid web page and their meta content. Here's the problem. When I run the crawler from a debug server instance of Visual Studio Express, and provide the starting instance as the IIS url, it works fine. However, when I do not provide the IIS instance and it takes its own url to start the crawl process(ie. crawling its own domain space), I get hit by operation timed out exception on the Webresponse statement. Could someone please guide me into what I should or should not be doing here? Here is my code for fetching the page. It is executed in the multithreaded environment.
I have an .Net Framework #4.0 application that makes a large number of web requests using the WebRequest/WebResponse classes , as i see it has memory leak (or maybe i am doing something wrong)I Wrote some small simple application that demonstrates this:
class Program { public static void Main(string[] args)[code]...
The only one solution i came up with is use GC.Collect() (unmarked in example) , All the object are disposed , all streams are closed , am I missing something ?I found something but i don't understand the reason , if i minimize Console the memory usage decreases and looks O.K , what can be the reason for that is there a problem with Conosole or WinForm .
I'm trying to make a webpage that get's a url from another web page (this other webpage works fine in a browser, both IE and FF) but when I make the webrequest call the returned page is a 500 internal server error. Here's the code:
Imports System.Net Imports System.IO Partial Public Class _Default Inherits System.Web.UI.Page Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
[Code] ....
Here's the error I'm getting:
Code:
System.Net.WebException: The remote server returned an error: (500) Internal Server Error. at System.Net.HttpWebRequest.GetResponse() at SW_GetDownloadFile._Default.GetDownloadFile(String Url) in C:Documents and SettingsvmMy DocumentsVisual Studio 2008ProjectsSW_GetDownloadFileSW_GetDownloadFileDefault.aspx.vb:line 24
The DownloadHandler.jsp page simply displays a text line being a text file download link, there's no html formatting or anything and when I paste that text into the browser it shows the text file contents just fine, I need my asp webpage to get that text file link so it can turn around and open it to parse the info.
I'm not in control of the DownloadHandler.jsp page so i can't alter that, the Java team wont make any changes to it either.
On my page which uses nested master pages, I have several user controls which are in their own UpdatePanels.
I've noticed that when I update something which is in UpdatePanel 2, things are shifting slightly in UpdatePanel 1. Someone told me that when UpdatePanels are used, the page is reloading anyway. Is this true?
How do I prevent UpdatePanel 2 affecting UpdatePanel 1?
P.S. All update panels are set to Conditional in their UpdateMode's.
I have an asp.net app that uses System.IO.Path.GetTempFileName() for temporary files. In the production IIS environment (W2K3), the temp folder (System.IO.Path.GetTempPath()) points to C:WindowsTemp. But on my XP dev machine it's C:documents and settingsmachinenameASPNET emp.
Is it possible to change this folder without affecting other accounts on machine?
I need to modifiy my web applicaiton without affecting current transaction.
i will be having some modification in almost all days.
Right now " i stop my application and update the necessary files and strat the application again". Means i am loosing all transaction in between that modification.
Is there any way i can update my changes without affecting transaction.
We're having an issue with a .NET 3.5 WebForms site where occasionally our error logs start filling up with the following error message:
"Multiple controls with the same ID 'ctl09' were found. FindControl requires that controls have unique IDs."
I know very little about the exception as I have never seen it while debugging locally and have never caught it in the error logs soon enough to run a remote debugging session. I do know that an application pool recycle fixes the issue.
This only affects a single [high traffic] page in the site. The strange thing is that the site uses the pre-4.0 ID generation logic. So, when the page is working, there isn't an html element in the entire view source that isn't some autogenerated control ID prefix followed by a the 'actual' IDs (i.e. ctl09_someID_someOtherID).
What would case a control to randomly stop being built correctly? Other than the Global.asax, how can I trap this error and force the control to ... recompile? App pool to recycle?
