How can we prevent page crash in asp.net? Is there any generic function or place like global.asax where we specify a file to redirect to when an unhanded exception occurs? (like we redirect to a specified page when 404 page not found exception occurs?
View 3 RepliesI'm building the standard 3-tier ASP.NET web application but I'm struggling as to where to do certain things - specifically handling exceptions.
I've tried to have a look around on the web for some examples but can't find any which go as far as a whole project showing how everything links together.
In my data-tier I'm connecting to SQL Server and doing some stuff. I know I need to catch exceptions that could be raised as a result but I'm not sure where to do it.
From what I've read I should be doing it in the UI tier but in that case I'm not sure how to ensure that the connection to the database is closed. Is anyone able to clarify how to do this? Also if anyone knows as to where I could find an example 3-tier web application that follows best practices that would be great too.
I put some global error handling in place, but am having problems testing it by causing unhandled exceptions.
Here's all I can think of at the moment. feel free to add to this list with more ways to trip unhanndled exceptions.
1) Dangerous form data - Entering characters such as < and > in a text box and trying to submit
2) Put invalid values in a URL parameter - eg if you page is www.test.com/home?testid=XXX where XXX is the form number/identity # you are trying to pull up, put a number that doesn't exist in the URL and hit enter.
I'm sure I could change some stored procedures or otherwise mess with my data access components but I'd rather not have to change any code anywhere...I want to be able to generate these exceptions on the front end, like a user would.
I'm working with a third party vendor at the moment who has supplied an ASP.Net web application. The web app generates around 200 unhandled exceptions per day, which end up as emails in my in-box. Upon investigation it turns out that most of these errors are triggered by the GoogleBot web crawler indexing the site and triggering access to another third party web service, which is rate-limiting the requests. When a request limit is exceeded, the third party web service refuses the request, this results in an unhandled exception in the web server and an HTTP/500 status code. The exception looks like this:
[code]....
The web app developer seems unwilling to handle these errors for reasons I don't really understand. Their approach is to throttle the GoogleBot until the errors stop happening (Google indexes quite aggressivley, generating around 5,000 hits per day). While I accept that throttling the GoogleBot would work, it seems like a cop-out to me. I've always considered unhandled exceptions to be bugs. Shouldn't the web app handle these errors? It is ever acceptable to allow an HTTP/500 to happen? What do the web developers out there think?
I noticed that IIS will return 500 error, but is there any other log in the IIS side?
View 4 RepliesI once saw that was possible to do something like adding a key in the web.config file to redirect to a default error page everytime a unhandled exception is found.
View 3 RepliesI didn't want to post anything before i search and upgrade to the latest ajax3.5I copied the zip extracted it in a location and then on vs2008 i added a toolbox and i imported the jaxcontroltoolkit.dll(the very first on the folder).
I got the controls and all is fine until then.
The problem (i previous had with the beta version) stayed.
I did not handle an exception and vs prompted me for the location of accordioncontrol.cs (i don't clearly remember the control), saying there is no source code and i should provide one.I clicked cancel (there is clearly no accordion .cs control on the zip) and the program got the exception on the web page.Ok.
Now everytime i put a breakpoint on the page and it reaches the last end sub it prompts me this "There is no source code available for the current location."I can hit F5 and pass this, however if i hit F11(next statement) it prompts me for the location of the picture i include here. I remember finding the cs somewhere for the beta and included it and it prompted me for wrong version or something on the unhandled exceptions so i have forgotten the error (because i usually handle all my exceptions so i didn't have any for a while).
I am getting this error:
Server Application Unavailable The web application you are attempting to access on this web server is currently unavailable. hit the "Refresh" button in your web browser to retry your request.
Administrator Note: An error message detailing the cause of this specific request failure can be found in the application event log of the web server. review this log entry to discover what caused this error to occur.
However there is no error in the application event logs. So I am wondering if there's a specific setting in IIS or for the virtual site that enables logging?
Changing the customerror setting in the web.config seems to have no effect. I don't think it's even getting that far. IIS 6, Windows Server 2003
"I DONOT WANT TO use the default error page tachnique, because i donot want the webpage to redirect!"
yes there is the try and catch
yes there are way to add exception handling mathods overwrite for controls
but what i need is,
it may just be a simple sql command,it may be a control such as formview, it may be a control such as datagrid, whatever it may be, when an illegal entry is done into the table of the database,
"THE BIG ERROR PAGE SHOULD NOT COME!!"
instead
a label at the top of the same page (where the illegal operation is performed) should display the error like
"error caused by "this control" and the error message is "null is not allowed in this field blah blah"
I am making MSSQL stored procedure CLR calls from ASP pages. When an exception occurs, it is logged and then rethrown. In this scenario I need to be able to handle the exception (if possible) in the ASP page. Note that I cannot move away from classic ASP in this instance; I am stuck within a legacy system for this project. let me know if you know of a way to handle the exceptions in classic ASP.
View 1 RepliesI have a simple method that is secured
[PrincipalPermission(SecurityAction.Demand, Role = "Administrator")]
protected void lnkClearCache_Click(object sender, EventArgs e)
{
}
If this is clicked without the role, it generates a System.Security.SecurityException: Request for principal permission failed. as expected.
I use ELMAH to handle logging for my errors, and I have a custom ELMAH event in my global.asax to transfer to the error pages in ways that preserve status codes which works correctly.
[Code]....
This works all well and fine and redirects to my error page which works properly, however instead of displaying the content as expected. I immediately get a second request for the error page but this time using the value of customErrorsSection.DefaultRedirect that does not come from my code in any way that I can see.
As far as I can tell it's almost as if when .NET raises an exception for PrincipalPermission and then lets the entire request complete, then after the request is complete it throws away the application response and instead responds with the default custom error.
When I'm debugging I do break on 2 separate exceptions for PrincipalPermission, whether this is a just a rethrow by .NET I'm not sure but my .NET code never sees the 2nd throw, nor does ELMAH. I always end up with a single response, single error logged, but that the url that finally renders to the browser is the default url and not 403 url that I specifically server.transferred to. If I browse to a /location that is secure I properly get the 403 error page.
Is there a way to globally handle exceptions in regular ASP.NET Web Service (asmx) using ELMAH like we do it in ASP.NET web site ?
View 2 RepliesI really want to switch over to ajax, but i can't seem to get my error handlling perfect. If i can't handle errors correctly, I just can't use it. What I really want to happen is to do a full refresh of the Top Frame. How I normally do this is by a similar call to Response.Write(<script>top.location.href = ""</script>). I was currently doing this in Global.asax. This becomes a problem when I error out in an AJAX postback. I've also noticed that There is an AsycPostbackErrorHandler you can attach to the ScriptManager. This is all find an dandy, but it will still hit my Global.asax Application_Error Event.
I am honestly just not sure how to handle this.
As I said, the result I want is....To Reload the Top Frame with some Error Message...whether I have to do some weird redirection or whatever. My problem lies specifically with the Global.asax file.
Looking for best practice focused answers here with explanations.
Should the presentation layer of an ASP.Net app catch and handle exceptions thrown from the business layer, or should these be allowed to bubble out, where they can all be logged and handled uniformly in the Global.ascx's Application_Error handler?
[code]....
In sqlserver2005 how to handle exceptions in stored procedures and
1)redirect to other page
2)write in to log file
string connectionstring = WebConfigurationManager.ConnectionStrings["AdventureWorks"].ConnectionString;
SqlConnection con = new SqlConnection(connectionstring);
DataSet ds = new DataSet();
DataRelation dr = new DataRelation("show", ds.Tables["HumanResources.Employee"].Columns["EmployeeID"], ds.Tables["HumanResources.EmployeeAddress"].Columns["EmployeeID"],false);
ds.Relations.Add(dr);
foreach (DataRow row1 in ds.Tables["HumanResources.Employee"].Rows)
{
Response.Write("customertitle:" + row1["Title"].ToString());
foreach (DataRow row2 in row1.GetChildRows(dr))
{
Response.Write("customer add" + row2["ModifiedDate"].ToString());
}
}
Object reference not set to an instance of an object. Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. Exception Details: System.NullReferenceException: Object reference not set to an instance of an object. Source Error:
[Code]....
Line 31: Line 32: DataSet ds = new DataSet();Line 33: DataRelation dr = new DataRelation("show", ds.Tables["HumanResources.Employee"].Columns["EmployeeID"], ds.Tables["HumanResources.EmployeeAddress"].Columns["EmployeeID"],false);Line 34: //ds.Tables["HumanResources.Employee"].ParentRelations.Add(dr);Line 35: ds.Relations.Add(dr);
Source File: d:databaseDataset showing selected
field of 2 tables.aspx.cs Line: 33
Stack Trace:
[Code]....
[NullReferenceException: Object reference not set to an instance of an object.] dataset__with_two_tables.Page_Load(Object sender, EventArgs e) in d:databaseDataset showing selected field of 2 tables.aspx.cs:33 System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +15 System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +33 System.Web.UI.Control.OnLoad(EventArgs e) +99 System.Web.UI.Control.LoadRecursive() +47 System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1436
We have a asp.net application and want to implement logging. The first idea was to use the Application_Error method in the global.asax file.
The problem is that ASP.NET very often seem to throw exceptions internally that are not caused by the application and which seem not to interfer with the users normal workflow. For example we often get HTTPExceptions, UnauthorizedAccessExceptions and others caught in this method, although there is no real error in the application.
How should I log exceptions? I never tried logging in .NET before. Nor try to dump exceptions to a txt (or binary) file. I dont require a text file, just a way to view the logs with the file and line #.
-edit- using asp.net
I have the following code
[code]....
and while that presents a friendlier error message to a user, I've forgotten how to show me the "real" error.
I have a set of WCF services which I have been using with an ASP.NET MVC application so far. These service operations return a FaultException when the server has identified problem with what the client has submitted. For example:
[code]...
However with Silverlight this all fails. The server returns a 500 status code with the faultexception (as expected) but to Silverlight this just looks like a duff response.
The following MS article indicates a (ugly) work around for this: [URL] This workaround makes the service transmit 200 status codes, even if there is a FaultException, so that the Silverlight client can get them. But this will mess up 'normal' clients of my service (my ASP.NET application, other users in the wild).
However, the point of services is to have seperation from your clients. I still want my services to return 500 status codes so that my ASP.NET application can detect the FaultExceptions and handle them. But I also want Silverlight to be able to handle them too.
string lNewHTML = Regex.Replace(lOldHTML, "(word1|word2|word3)", "<a href="page.aspx#$1">$1</a>", RegexOptions.IgnoreCase);
The code works, but I need to include some exceptions to the replace - e.g. I will not replace anything i an img-, li- and a-tag (including link-text and attributes like href and title) but still allow replacements in p-, td- and div-tags.
I need to handle 404 exceptions differently than all other types of them. What is the best way to identify those 404 exceptions (distinguish them from other exceptions)?
The problem is that there is no a special exception class for 404 errors, I get regular System.Web.HttpException with Message = "File does not exist."
Should I just use exception's message for it or is there a better way?
I have a datasource that uses a business logic object for the select event. How can I catch an exception that occurs in the business logic layer and pass it to my presentation layer to display to the user in a label?
View 1 RepliesThere used to be an article at ELMAHs docs site that contained this information, but it seems to have been removed. I think it's as simple as setting a configuration setting in the section, but I haven't a clue what it isCan anyone take a few seconds and drop the configuration setting here?
View 1 RepliesRemoteOnly" defaultRedirect="~/Errors.aspx">
<error statusCode="404" redirect="~/Error.aspx?code=404"/>
</customErrors>
hrow new HttpException(404, "404 Not Found");