.NET Tutorials, Forums, Interview Questions And Answers
Welcome :Guest
Sign In
Win Surprise Gifts!!!

Top 5 Contributors of the Month
Gaurav Pal
Post New Web Links

FileUpload & Try Catch

Posted By:      Posted Date: September 16, 2010    Points: 0   Category :ASP.Net
With the fileupload component I was trying to catch errors and write to the literal - ltlIDDocsProblem is when I test this out and try and upload a .exe (which a user might mistakenly do) with the sub below (some of the code is removed for brevity) I get a white screen error message.Is there anything I can do to stop this.Protected Sub ButtonIDDocs_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles ButtonIDDocs.Click  Try          Dim FileUpload1 As New FileUpload         FileUpload1 = CType(Wizard1.FindControl("IDdocuments"), FileUpload)          Dim FileOk As Boolean = False         Dim FileSizeOK As Boolean = False           If FileUpload1.HasFile Then               Dim fileExtension As String             fileExtension = System.IO.Path.GetExtension(FileUpload1.FileName).ToLower()             Dim AllowedExtensions As String() = {".jpg", ".jpeg", ".gif"}             For i As Integer = 0 To AllowedExtensions.Le

View Complete Post

More Related Resource Links

SQL Server 2005 Try and Catch Exception Handling

I'm pretty excited to see that there is some real error handling for T-SQL code in SQL Server 2005. It's pretty painful to have your wonderfully architected .NET solution tainted by less-than-VBScript error handling for stored procedures in the database. The big difference being the addition of TRY..CATCH blocks. Let's take a look:

Server side validation of Fileupload control not working



I've tried this method in my code behind to try and validate that the Fileupload control has a file or not. I get the error message the the event "Server Validate" cannot be found. Can anyone tell why? Thanks.

Public Sub CustomValidator1_ServerValidate(ByVal source As Object, ByVal args As System.Web.UI.WebControls.ServerValidateEventArgs) Handles CustomValidator1.ServerValidate

' Get file name

        Dim uploadAvatar As FileUpload = DirectCast(AdvertisementForm.FindControl("uploadAvatar"), FileUpload)

        Dim UploadFileName As String = uploadAvatar.PostedFile.FileName

        If UploadFileName = "" Then
            ' There is no file selected
            args.IsValid = False
            Dim Extension As String = UploadFileName.Substring(UploadFileName.L

reader.getordinal("column_may_not_exist") how to catch the exception?



would any body please help me to catch the exception if the column doesnot exist as my table columns are not static.

sometimes its throwing me indexoutofrange exception as the column doesnot exist

thanks for the help guys

FileUpload Class SaveAs, how can you overwrite?

Hello all,

I'm trying to use 2.0 class, FileUpload. 
Namespace: System.Web.UI.WebControls
Class FileUpload

Anyway, in my code can save the file to the server

FileUpload1.SaveAs(SavePath + FileName)

Problem is I can't find a way to overwrite the file.  When I try and run the program again is says the file is already in use that a process has access to it.

Is thre a proper way to release control of whatever it grabbing hold of it?  In .Net I don't have to destroy my objects right?
Or is there a way to specificly overwrite the file? It seems that SaveAs does that.  Just trying to figure out why I can upload this text file, but sometimes only once and then I have to code in to check to see if it exists then rename it.

FileUpload error: Object reference error


I have a FormView with a FileUpload to upload an image in a database.

I keep getting an object reference error.(view code)

I am using this same script to upload the image to the database, but when I try to update the file upload I get the error.    

string strFilePath=Server.MapPath("\\images\\"+fupdImage.FileName);

        Byte[] image=null;
        HttpPostedFile imgVid=FileUpload.PostedFile;

        image=new Byte[imgVid.ContentLength];//Object reference not set to an instance of an object.

        if(FileUpload.HasFile) {
        string imageFile=FileUpload.PostedFile.FileName;
        int index=imageFile.LastIndexOf(".");
        string fileFormat=imageFile.Substring(index+1);


How to CATCH "Invalid postback or callback argument" exception?



How can I catch this exception? I do not want it to stop my page execution. Can/Should I do that?

Server Error in '/' Application.
Invalid postback or callback argument.  Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page.  For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally rendered them.  If the data is valid and expected, use the ClientScriptManager.RegisterForEventValidation method in order to register the postback or callback data for validation.
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.ArgumentException: Invalid postback or callback argument.  Event validation is enabled using <pages enableEventValidation="true"/> in configuration or <%@ Page EnableEventValidation="true" %> in a page.  For security purposes, this feature verifies that arguments to postback or callback events originate from the server control that originally

Using the BDC API how to catch the returned code when executing a stored procedure?

using BDC API, how can i catch the return code a stored procedure returns?

I tried Entity.Execute to execute a generic method. However, it returns an empty Entity table.

I know you can do it by setting up an output variable. I prefer returning an integer for tracking errors.

Any ideas?



FileUpload.SaveAs is configured to require a rooted path. but "http:// --- is not a rooted path


Hi Friends

when i am uploading image to http://filepath i got the 

The FileUpload.SaveAs Method is configured to require a rooted path but http:// filepath is not a rooted path

my code is as follows

If (Fileupload.HasFile)


Dim filepath As String = http://filepath/

FileUpload.SaveAs(filepath & String.Format("datafield_{0}_b.jpg", textbox.Text))

End If

Please help me




FileUpload Access Denied


Hi all.

I have done much research on this and am still stumped.

I have a ASP.NET 2.0 application, running on Windows 2003 Server. IIS 6.0

I am using Windows authentication , and I am not using impersonization, and I set my trust levvel to full.

<authentication mode="Windows"/>

<identity impersonate="false"/>

<trust level="Full

Catch button click event in different .aspx page.


I have a button which starts processing.
I want that when ever a button is click from page1.aspx .. a count down timer should start and displayed on page2.aspx.
I am thinking of using iframe to join 2 pages.

Please let me know your suggestions.


FileUpload Control with membership and roles


Hi Everyone!

I'm pretty new to development using Microsoft technologies.

I'm trying to build a portal kind of an application in asp.net, in which one of the functionality is letting people log in and upload their documents. The upload page is only accessible to registered users of the portal.


I would like to track the user uploaded files according to their userIds.

Is it possible to use the FileUpload Control and C# to fetch the current user id, create a directory with the same name(as that of userID) in the file system and upload the files( multiple file upload, if necessary) into it?

Also another admin page would have to be able to see the list of files uploaded by the specific user and download it if necessary.

Could anyone help me with this?

I'm also expecting alternate solutions to the problem.

Awaiting a response.

Thanks in advance 


Add Release-Only try-catch to CLR languages

Deploying a software, it's a common practice to encapsulate top-most function calls and/or event handlers with general try-catch blocks to deliver an error description to the user instead of just having him/her see the software exiting unexpectedly when unexpected exceptions occur. Unfortunately, during debugging it is most annoying to reach these log entries or message boxes instead of having Visual Studio halt where the exception occured. At the time of writing it is possible to designate particular exception types to halt the debugger when they are actually thrown. But it becomes a nuisance when there are many exception types to be marked this way. Plus, it becomes contra-productive if there is a scenario when expected exceptions of the marked types occur regularly and "Continue" has to be selected again and again in the debugger. Thus, I'd like to suggest to add a new, Microsoft specific, "try" keyword to all of the CLR languages (plus C++), perhaps something like "__try". This new kind of try should create a try-catch block only when compiling in Release mode. (This behaviour might apply to other configurations as well. I suppose the Configuration Settings dialog to provide an additional checkbox column to provide an option to select whether a particular configuration will create a try-catch block or not.)   See here for

Unable to catch WCF EndpointNotFound exception in SecurityToken.GetToken( . )

I have a set of WCF services that I am integrating with, I can not change them in any way because they are provided by a third party. I use a username/password scheme to authenticate with the services. If the services are not available I get an exception (EndPointNotFoundException) from the SecurityTokenProvider class that I can not catch. I understand why the exception is being thrown, I just need to know how I can handle it so that I can gracefully handle the errors in the user interface. Is there a way I can catch this exception or a better way to handle this scenario? The Exception The exception is thrown from System.IdentityModel.Selectors.SecurityTokenProvider : GetToken( TimeSpan timeout ) public SecurityToken GetToken(TimeSpan timeout) {    SecurityToken token = this.GetTokenCore(timeout);     if (token == null)    {        throw DiagnosticUtility.ExceptionUtility.ThrowHelperError(new SecurityTokenException(SR.GetString(SR.TokenProviderUnableToGetToken, this)));    }     return token;} The channel open part When I open the channel I have it wrapped in exception handling, but none of it seems to trap the SecurityToken exception. I am using the ExceptionHandlingProxyWrapperBase try{    this.Open();} catch( EndpointNotFoundException epnfe ){    // Handle the exception} catch( E

How to catch click from link inside widget

Hello,I have an ASP.NET (3.5) page. On the page there is a widget.  Here is the page code:<%@ Page Language="C#" MasterPageFile="~/MasterPage.master" AutoEventWireup="true" CodeFile="Stiri.aspx.cs" Inherits="Stiri" Title="Stiri in Teleorman" %><asp:Content ID="Content1" ContentPlaceHolderID="head" Runat="Server"></asp:Content> <asp:Content ID="Content2" ContentPlaceHolderID="ContentPlaceHolder1" Runat="Server"><script language="javascript" type="text/javascript" src="http://www.presaonline.com/ajx/webmasters/get/0/?tidings_number=5&show_image=on&show_body=on&show_county="></script></asp:Content> The widget (script) displays a list of news from another website like this:---------------------------------------------------------title1 (as link)short descriptiontitle2 short description.............................................---------------------------------------------------------1. When a user clicks on one of the links in the above list I want to "catch" the link.2. ISSUE: When the link (from the list) is clicked the URL is opened in another browser tab3. If a user clicks on a link I want to redirect him not to the link's URL but to a page of my website.I

Catch Block question

What are the scenarios in which a t-sql catch block will not be called?   I have a SP which does partition management, sometimes i see that partitions have not been properly created... but still the catch block was never called. This is getting very hard to debug.   Can it be that in some timeout scenarios the catch block is not called?

try catch block

Hi Guys, I have a very simple question. whether to put the select stmt in try/catch or not? Its advantage,disadvantage if any will be of great help.~Technology Analyst~

Getting an error using FileUpload Control on a server.

Hello FriendsI m getting a problem while executing the following code for my website.This code works perfactly on localhost but when I use d same code on my webpage on the server it does nothing...even it doesnt return any error msg.Plz help me...protected void BtnUpload_Click(object sender, EventArgs e) {        int intFileSizeLimit = 1000;               string strFileNameWithPath = FileUpload1.PostedFile.FileName;               string strExtensionName = System.IO.Path.GetExtension(strFileNameWithPath);              string strFileName = System.IO.Path.GetFileName(strFileNameWithPath);           int intFileSize = FileUpload1.PostedFile.ContentLength / 1024;                              strExtensionName = strExtensionName.ToLower();        if (strExtensionName.Equals(".doc") || strExtensionName.Equals(".txt") || strExtensionName.Equals(".docx"))        {      
ASP.NetWindows Application  .NET Framework  C#  VB.Net  ADO.Net  
Sql Server  SharePoint  Silverlight  Others  All   

Hall of Fame    Twitter   Terms of Service    Privacy Policy    Contact Us    Archives   Tell A Friend