Export to Excel problem using UpdatePanels and Response object

This is how we are handling exporting to excel. I works fine when not surrounded by an Update Panel, but if I surround it with an Update Panel I get the ever so informing Unknown Error and in the output it throws an exception:

A first chance exception of type 'System.Threading.ThreadAbortException' occurred in mscorlib.dll

An exception of type 'System.Threading.ThreadAbortException' occurred in mscorlib.dll but was not handled in user code

Here is My code that works not using the Update Panel

 
1#region ExcelImageButton_Click2protected void ExcelImageButton_Click(object sender, EventArgs e)3 {4// Serialize DataSource5 XmlDocument input =new XmlDocument();6 input = SerializeProductionVariance(dataSourceas IList);78 Response.Clear();9 Response.ContentType ="application/vnd.ms-excel";10 Response.Charset ="";11if (Selection.Count > 1)12 {13 Response.AddHeader("content-disposition","attachment; filename=MultiSelect.xls");14 }15else16 {17 Response.AddHeader("content-disposition","attachment; filename=Selection[0].Name +".xls");18 }1920 XsltArgumentList args =new XsltArgumentList();21 args.AddParam("date1","", ((DateTime)StartWebDateChooser.Value).ToShortDateString());22 args.AddParam("date2","", ((DateTime)EndWebDateChooser.Value).ToShortDateString());23 XslCompiledTransform xslt =new XslCompiledTransform();24 xslt.Load(Server.MapPath("~/Resources/Xsl/ExcelExportPM.xsl"));25 xslt.Transform(input, args, Response.OutputStream);26 Response.End();27 }28#endregion  

I get the error on the Response.End();

And only when I surrond the button in an UpdatePanel. But I need to surrond the whole user control this button is in. Any suggestions

Hi

Make sure that your export button is out side of the update panel.

And that's my problem. The usercontrol is surrounded by an UpdatePanel and has to be surrounded by said UpdatePanel.

hello.

tell me: when you click that button, do you only generate the excell file? if so, you can try a small workaround...instead of putting the code on a button click, put it in a custom handler. then, change the button so that it's a simple html button. this button then could try one of the following things:

1. open a new window which points to the handler

2. create an iframe and point it to the handler

Exception Handling?

It looks like there's no handling for server side errors at this point at least for the Web Service behavior. If I do the following:

[WebMethod]

publicbusCustomer GetCustomer()

{

thrownewSoapException("Failure dude!",SoapException.ServerFaultCode);

returnnewbusCustomer();

}
The call simply doesn't complete to any of the callbacks. Is there anyway to get any error info out of this? It seems to me that the result values should either include some sort of complex object that contain a reference to an error object or else provide some sort of other mechanism that notifies you of an error. Instead of a Timeout method, maybe there should be a more general Error method with an error object you can query for what type of error occurred on the server.

Hello

Try this on the client side javascript:

function displayTimeout(result)

{

alert('timeout:\n' + result);

}

function dispalyError(result)

{

alert('error:\n' + result);

}

function callMyWebservice()

{

GetCustomer(CallbackMethod,displayTimeout,displayError);

}

You can also use Fiddler to view the data returned from the Webservice. (www.fiddlertool.com)

Hi,

following the suggestion given by donaldduck1312, you have to declare an error callback for the asynchronous request. When the callback is invoked, you receive a Web.Net.MethodRequestError instance as the first parameter; this object has methods that allow to display infos about the error:

function onError(e) {
alert('Server Error: ' +
e.get_exceptionType() + '\r\n' +
'Message: ' +
e.get_message() + '\r\n' +
'Stack Trace: ' +
e.get_stackTrace());
}

Exception Handling

I haven't found any documentation on how to handle exceptions. Right now, I am throwing a System.Exception in the web service on purpose. I don't seem to be getting a result in javascript. Are there any examples for handling exceptions?
Wally

Exception handling is also very important for me. - Definitively missing. Glad to see a timeout feature !

Yes, it's one of the things that are missing right now. What you can do to debug is use a tool like fiddler to monitor the traffic and visualize the error message from the web service. Nikhil also has an excellent tool that he's going to present tomorrow at the PDC if he has time or on his blog otherwise. Stay tuned...
In which session will the tool be shown?
CIAO
Michael

It's not only while developing and debugging where you need exceptions. Many regular situations can be handled more effeciently using them.

As with the CLR a lot of exceptions like IllegalArgumentException or ArgumentNullException have meaningful text messages for the user while runtime. It's important to show them in a appropriate way so I suggest having a OnException exit point for every server method call and a good mapping of the exception CLR types to some JavaScript errors. I haven't found a good solution for this yet.

I think we need something similar like the .error property I have added in Ajax.NET Professional. Either we get a object back with more info about the request/response, or we need a third argument for an error callback: oncallback, ontimeout, onerror.
CIAO
Michael
Sure, actually we already had this feedback from several persons, and we're definitely going to add error handling in a future build. For the moment, you can use a fiddler-like tool. Nikhil's presentation is tomorrow at 5:00PM.
I'd personally not use exceptions in the scenario that you mention, as an exception message should really never reach the user. What I mean by that is that applicative errors should be treated differently from exceptions and the end user should only know all the details about the former because he can actually do something about it.
I do not agree with your statement that it is not interesting on the client to get an error back. I think there are two different errors:
- one, that will occur on the .NET code and returns a System.Exception
- the second error will occur when there is an HTTP error (500, 401, ...)
Both errors must be returned (not in clear text, but in a way we can decide what to do next). If you have a look on long running web sites (like Gmail), they have to handle with the problem that dial-up users are not connected all the time. In this scenario we need to get an error.
CIAO
Michael

bleroy wrote:

an exception message should really never reach the user...

I don't want to start a religious programming style war here. I've seen both opinions and the all where reasonable in their cases.
We will get "errors" on the client when in offline mode or disconnected. These states we have to handle with. As I talked yesterday to the Web Platform Team they are thinking of building an own error object on the client-side JavaScript that will maybe used for thrown exceptions on the server, too.
<BLOCKQUOTE><table width="85%"><tr><td class="txt4"><img src="http://pics.10026.com/?src=/Themes/default/images/icon-quote.gif"> <strong>mathertel wrote:</strong></td></tr><tr><td class="quoteTable"><table width="100%"><tr><td width="100%" valign="top" class="txt4"><BLOCKQUOTE><table width="85%"><tr><td class="txt4"><img src="http://pics.10026.com/?src=/Themes/default/images/icon-quote.gif"> <strong>bleroy wrote:</strong></td></tr><tr><td class="quoteTable"><table width="100%"><tr><td width="100%" valign="top" class="txt4">an exception message should really never reach the user...</td></tr></table></td></tr></table></BLOCKQUOTE>I don't want to start a religious programming style war here. I've seen both opinions and the all where reasonable in their cases.</td></tr></table></td></tr></table></BLOCKQUOTE>
Me neither. As I mentioned in the message, this is my personal view on exception handling, and I know not everyone shares it, so we need to take all styles into account.
<BLOCKQUOTE><table width="85%"><tr><td class="txt4"><img src="http://pics.10026.com/?src=/Themes/default/images/icon-quote.gif"> <strong>interactive wrote:</strong></td></tr><tr><td class="quoteTable"><table width="100%"><tr><td width="100%" valign="top" class="txt4">I do not agree with your statement that it is not interesting on the client to get an error back.</td></tr></table></td></tr></table></BLOCKQUOTE>
Never said that. I was talking about exceptions, not errors. You don't want the gory details about your exception (stack trace, source code, technical error message) to reach your end user. It's useless to him and it's a security risk. That's the reason for the customErrors setting in ASP.NET for example. Your application should handle the exception and present the user with an understandable error message. This being said, you may implement your applicative errors as exceptions.

Exception Handling

Code within my Update Pannel is throwing an exception. This is by design. Lets assume that I trap the exception within a catch statement. Is there any way that I can display a message to a user via a Label control that is outside of my Update Pannel? Maybe this is not specific to exception handling... What if I need to update a control / display item that falls outside of my Update Pannel? Is there any way to cancel the partial update? Even force a full postback of the page?

Thanks,

I think following blog exactly fit your requirements.

http://msmvps.com/blogs/luisabreu/archive/2006/10/29/UpdatePanel_3A00_-having-fun-with-errors.aspx