I have some code that is throwing unhandled DivideByZero exceptions in a WebMethod. These exceptions are not being caught by the global logging in Application_Error in global.asax. why exceptions thrown from a WebMethod are not handled by Application_Error?
View 3 RepliesI 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.
The default behavior of a [WebMethod] attributed static method on an aspx page is to return the error to the caller. We are accessing these methods using json, and the only way we have found of capturing exceptions is either a try/catch in every webmethod on the site or using a javascript callback with the error (which has the unacceptable downside of exposing the error to the client).
Is there any way to globally handle these exceptions using the HealthMonitoring setup in ASP.NET?
Thisis the code I use to display an aspxloadingpanel with an ms update panel:
var prm = Sys.WebForms.PageRequestManager.getInstance();
prm.add_initializeRequest(initializeRequest);
prm.add_pageLoaded(pageLoaded);[code]....
However when an error occurs on this page, the loading panel continuously remains on the screen...How can I catch errors so that instead it would actually show the error.
Imagine a web service with a method that returns a Customer object, that takes a customer ID as a parameter, i.e.
[WebMethod]
Customer GetCustomer(string customerId)
Now imagine that you're writing an ASP.NET app and you've generated a proxy for the service with the async operations. You create an instance of the service, wire service.GetCustomerCompleted to your handler, OnGetCustomerCompleted, and call service.GetCustomerAsync("12345"). In OnGetCustomerCompleted you apply logic to detect that no customer was found and throw a custom exception, or you want to throw the exception found in e.Error, e.g.:
void OnGetCustomerCompleted(object sender, GetCustomerCompletedEventArgs e)
{
if (e.Error != null)
throw new ApplicationException("GetCustomer failed", e.Error);
if (String.IsNullOrEmpty(e.Result.FirstName) && String.IsNullOrEmpty(e.Result.LastName))
throw new CustomerNotFoundException();
}
(I've omitted the bits of code that sets up a Customer object and persists it through the calls.) You launch the call to GetCustomerAsync in Page_Load and expect to retrieve the result in a handler wired to Page.OnPreRenderComplete. My question is, how do you catch the exception in your page? I know you can catch it with Global.asax's ApplicationError, but what if you don't want to navigate away from your page?
I'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.
The intent is to create a set of web services that people can reuse. These services mostly interact with a backend DB creating, retreiving and processing data. We want to expose services so that people can use to create data mashups and other applications.End users are webpages that can be within our domain or outside our domain. For pages outside the domain we plan to release widgets that would be configured to retreive and display the data.
One requirement - application should be extremely scalable in terms of the number of users it can handle.Our code base is .net and we are looking at ASPX webmethods (or ASHX), ASMX webmethods and WCF (starting to read up on WCF). In terms of security/access I found that maintaining sessionid, memberships is doable in all three. WCF seems a bit complicated to setup. I could not immediately see the value of asmx when we can get all done just using a webmethod in aspx (with a little tweaking). Also, assuming that with the ASP.NET MVC2 I might be able to get clean urls as well for these webmethods.QuestionsWhich one will be the most effective in terms of performance and scalability? Any reason why I should choose WCF or ASMX?
EDIT I kind of understand that WCF is the way to go. Just to understand the evolution of the technologies it would be good if someone can throw light on why a aspx webmethod is different from an asmx when similar things (apart from discovery) can be accomplished by both. The aspx webmethods can be made to return data in other formats (plaintext, json). Also, it seems that we can build restful services using ashx.
Using VS2008 SP1, .NET 3.5 SP1, C# Web Application Project
As we know, Web Application Projects (unlike Web Site Projects) compile the entire site for deployment. We have discovered a situation where the visual studio compiler doesnt catch and error. Then when we deploy the dll to the website (or even just run it in the built in web server) it catches the error and displays it as a "compilation" error during runtime. This is obviously disturbing. Let me explain the error:
Take a single web page in a new C# web app project, such as the default.aspx. Add a checkbox. Create an event handler for the checked changed event. Note that it modifies the .aspx file to add oncheckedchanged="yourmethodhere" in the checkbox item. Compile and everything is fine.
Now change the name of the method in the .aspx file, say for yourmethodhere to yourmethodhere_1 and compile again. Note you havent change the code behind, so you SHOULD get a compile error. But you dont. Now if you deploy or debug it, you will get a compilation error during runtime.
Note: If you do exactly the same thing in a web SITE project, the validation compile that it does when you choose to "build" the project DOES catch this error. In other words, only c# web APPLICATION projects have this problem.
we recently converted our web application from VS 2008 to 2010 and i am getting following error most of the time, both in my local machine (windows 7) and test server (windows 2003 server). Could not load file or assembly 'VJSharpCodeProvider, Version=4.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) I already wasted a lot of time on this and it is stalling me to move ahead and do further development.
View 1 RepliesI am getting this error, and cant figure out what the issue is.
Server Error in '/' Application.
Parser Error
Description: An error occurred during the parsing of a resource required to service this request. Please review the following specific parse error details and modify your source file appropriately.
Parser Error Message: 'JobManager.Contact' is not allowed here because it does not extend class 'System.Web.UI.Page'.
Source Error:
Line 1: <%@ Page Title="Contact" Language="C#" MasterPageFile="~/Site.master" AutoEventWireup="true"
Line 2: CodeBehind="Contact.aspx.cs" Inherits="JobManager.Contact" %>
Line 3:
Source File: /Contact.aspx Line: 1
Version Information: Microsoft .NET Framework Version:4.0.30319; ASP.NET Version:4.0.30319.1
The code behind syntax is:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace JobManager
{
public partial class Contact : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
}
We're using an Out-of-Process Session Provider (ScaleOut) for an ASP.NET application and we've noticed that when an object that's not correctly setup for de-serialization inadvertently makes its way into session it will eventually cause the entire process to terminate.
Reproducing and handling this scenario is where it gets even more interesting.
The exception that terminates the process is raised in AnyStaObjectsInSessionState whose implementation is pretty straightforward:
[code]....
I created a web application using visual studio 2010 / MVC2 / MSSQL 2008 and it runs fine in my laptop. However when I run the application in the hosting provider it shows the error message below:
Compiler Error Message:
CS0308
The hosting provider is [URL] and the link to my web application is [URL] I would like to know how to solve this issue? If anyone know PLEASE let me know how to troubleshoot / fix this issue. Also in case the problem is on the hosting provider, let me know if you know of a free or very affordable hosting provider with support for MVC 2 and MSSQL 2008.
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.
I 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).
how I can make my VWD2010 show the window where I tick which exceptions I want the debugger to halt on throw rather than unhandled? MSDN docs imply that the menu can be customized to add it but this is NOT TRUE for my version
View 2 RepliesI have what is probably a basic question, but I am rather new to writing exception handling code. I thought I understood the concept, but apparently I don't, heres the code:
[Code]....
If I enter in any non-integer values, the textbox is set to nothing and the label displays the error message. However, now that I have verified the textbox contains an integer, I want to continue on and use that value. The remaining code works fine unless there was an exception, in which case the conversion to an int value for x throws an error.
All the examples I have looked at demos the structure of try-catch-finally, but in this instance I am not performing any clean up, I want to execute code when a valid value is entered into the textbox.
I have a couple of questions on exception handling in .net: 1- Why do we have to catch specific exceptions other than the reason of displaying a particular error to the user? What if we wanted to always display a generic error to the user and not give him much details, would it be okay to catch only generic xceptions?
2- Is throwing exceptions from the data access layer to the UI layer best practice, or is it recommended to return a string or perhaps a boolean values from the data access layer to the UI layer?
I have been tasked with implementing a strategy to catch all errors in an ASP.net application which cause a user request or interaction to crash and then e-mailk this exception to a support team in advance of a user calling about the error.Some errors however are not causing the page to crash or be redirected to the custom error page but these are being emailed to the support team instead of simply being loggedMy requirement is to seperate what exception types will cause a page fail and which will not.Example I am currently receiving a System.Web.HttpUnHandledException which is not causing any page to fall over and therefore is not of relevance to the support team. this can be logged but does not require emailing.
View 1 RepliesI am using VWD Express 2010 Beta 2. Get the error: "the application cannot start", followed the blog [URL] and executed C:Program Files (x86)Microsoft Visual Studio 10.0Common7IDE>vwdexpress /rese tuserdata in the command prompt (run as administrator). but the error is still there when starting VWD.
View 2 RepliesWhen attempting to publish a web application from Visual Studio 2010, I receive the following error: Get service of SVsBuildManagerAccessor fails I'm using Visual Studio 2010 Ultimate (x86) on Windows 7 Professional (x64). I've attempted publishing the web app via FTP and Local File System and receive the above mentioned error. I've searched the internet for the error but have found no solutions.
View 10 RepliesI recently updated my VS2010 website project from .NET 3.5 to 4.0. Everything was working fine in the website project. Today I decided to migrate the website to a web application project as I have learned this is the best way to work in .NET. I split out all my class files into a separate class library and copied all my other content into my new project. Then I updated all the references and web.config.
When I build the class library, everything works great. The problem is happening when I try to build/debug the web application project. It is acting like all the controls are missing and it is also throwing a bunch of compile errors about the public properties I have in my master pages.
Control errors: "The name 'INSERT CONTROL NAME HERE' does not exist in the current context"
Master page errors:'System.Web.UI.MasterPage' does not contain a definition....
It is giving these errors for every single control and master page property in my entire solution.I notice when I add a new web.form to this project, it also adds a filename.aspx.designer.cs file in addition to the .aspx and .aspx.cs file. My existing files do not have these extra files since they were created in a different .NET version.
UPDATE: It seems I was missing the step where I need to right click on the new application folder and select "Convert to web application". I just did that and it seems to be a little bit better...
Now it is choking on Literals that are inside single quotes:
<div class='<asp:Literal ID="CssClassLiteral" runat="server"></asp:Literal>'>
It doesn't see this literal when it does the conversion... Is the above valid code or should I implement that functionality another way?
I am developping the ERP Web Application. My solution structure is as given below. Main Web Application - Having reference to All Module Web Application. Common Web Application - Has Master Page, User Control, Login page, Defualt Error and etc Module Web Application - Having Module wise Aspx and code behind. It refer Common Web Application to reduce redundacy. In this Context we are facing the following problem.
1) while running web application in the debug mode it gives error as 'the target assembly contains no service types. You may need to adjust the Code Access Security policy of this assembly'
2) Could not Debug both Module and Common Web Application.
3) In Design Time both Master or user control not renders in refered Aspx Page.
4) While I debug in visual studio 2010, it gets restart after some time.
I am LINQ querrying against a datatable. However, I am unsuccessfull with catching null values. Here is my code that is giving me the following error.
[Code]....
I am checking to see if minperc is null. However to check that it still is trying to convert the value to double. Cant figure out a way around it. Here is the error: Cannot cast DBNull.Value to type 'System.Double'. Please use a nullable type.
how to integrate my asp.net application to sharepoint 2010?
View 3 Repliescalling a SAP Webmethod using ASP.NET application.
View 1 Replies