I am trying to learn a bit of input validation, using exceptions and so on. I have a form with 3 textboxes: txtDay, txtMonth, txtYear, and a button cmdValidate.When cmdValidate is clicked I want to validate the textboxes to ensure there is no blank or non-numeric input but also that the date entered is a feasible one (i.e. day has to be between 1 and 31, month 1 and 12 etc).Now I know how to do this using nested If/Then/Else statements (If txtDay.Text = "" Then, Else If Not IsNumeric(txtDay.Text) blah blah) but I was told that using Exceptions would be a preferred, cleaner approach.As far as Exceptions go, I have a basic understand of Try/Catch/Finally but do not know how to catch the specific errors I listed above.
I've just skipped around a few inbuilt VB classes' methods which throws exception. of all that i've came across, methods may throw multiple exceptions but ALL of them are exclusive, meaning there is no way 2 exceptions will ever occur simultaneously, yea and i was trying to make my class throw 2 exceptions simultaneously, hence this question, must all exceptions be exclusive?
I am writing below code for validating compulsary field account no. in form.User's requirement is set focus back on field when error comes :
If txtAccountNo = "" Then MessageBox.Show("Account no filed can't be left empty") txtAccountNo.SetFocus Exit Sub End If
It's working properly. But suppose user don't want to fill form and exiting from application.Message box keep on appearing till user enters account no.
On my form, i've got some textboxes and some richtextboxes. I'm using the following code, to search through the text properties of each of the two types of control. see below:-
For Each ctl As Control In Me.Controls If ctl.Text = "7777" Then ctl.Text = "found the sevens" End If Next
What i'd like to do is isolate the textboxes only, is there a way to do that? I tried this but i got an error:-
For Each box As TextBox In Me.Controls If box.Text = "7777" Then box.Text = "Found" End If Next
My goal is to, Pull information from a websight's textboxes in IE into my program textboxes. and to later Put changes from into other values on the websight from my program into it. The sight has multiple textboxes, on different frames. within it.I need to keep it as a exsiting open browser instead of making a new one. only gotten as far as finding the open internet explorer window, by useing
I need to write a program that indicates the larger of two variables using exceptions.I'm not sure if this is an acceptable code. I'm new at this and attempted with this code here:
[Code]...
I normally wouldn't use an exception but I am asked to use one, I'm just not sure what kind of exception would work best.
I'd like some advice on building in known errors. Let's say I have a Windows form that needs to set the source path of an image in an object. It must be:
I have a class that has a method A and a helper method B, method A internally calls method B. method B throws few exceptions to the caller also method A throws it's own exceptions, Assume method A throws "NotImplementedException" and Method B throws "SQLException", in the XML of each method, one which method that should put "NotImplementedException" and "SQLException" in <exception cref></Exception >
Should i put both exceptions on the XML of method A?
I'm working on an ASP.NET web application, written using Visual Basic, and I'm trying to track down an error message that I'm getting.I'd like to get it to log the exception to a file (or the event log) so I can see it, as the error only occurs on the production server, and not on the development environment (therefore VS isn't installed on there...).
Does anyone have any thoughts as to best practice as to how to do this ?
Why is the net filled with examples like this? Why do people just chuck try catch around any expression with out the slightest thought about pre-validation?
i would never just add try catch and not handle the exception. I tell people this is basically on error resume next in disguise.
Is an exception ever unimportant to just use try catch but with out any message?I really want to progress as a programmer but have i been approaching all this wrong?
When you use Try Catch for Exceptions, will Catch ex As Exception Catch any possible error that could occur or do you have to catch each exception separately?
Is there a way to catch these Exceptions? (I am not looking for "just put try/catch or on error goto around them"). I am trying to find out if these errors can be caught by something outside of them.[code]...
I have a project that runs perfect under windows xp. Now I have tried to run it under Windows 7 and got there a lot of exceptions under Immediate window.
A first chance exception of type 'System.ArgumentNullException' occurred in Microsoft.VisualBasic.dll A first chance exception of type 'System.IO.FileNotFoundException' occurred in LP_Wizard.exe
[CODE]...
What wrong with that Microsoft.VisualBasic.dll in windows 7 and how i correct that problem ?
I have a SqlDataSource that is supplying data to my GridView. Thats all i am using on my form, thus i have NO code behind at all. But somewhere i need a TRY CATCH block just in case my connection get's lost. What code must i place where?
If i get a error i want my lblMessage Text to be "No connection".
Client(winforms MDI) is generated using svcutil using /l, /r, /ct, & /n switches
Service and client both use a MyEntities.dll
I am using nettcp with TransportWithMessageCredential. I cache the proxy in the main form
if Membership.ValidateUser(UsernameTextBox.Text, PasswordTextBox.Text) _proxy = new MyServiceClient _proxy.ClientCredentials.UserName.UserName = "username"[code].....
Could I subscribe to the _proxy.InnerChannel.Faulted and do that clean up there?
Is there a way to catch all SQL exceptions in a project? I have several gridviews and multiple sqldatasources and most of the errors are going to occur when a user enters something incorrectly or in the wrong column. So how do I stop the Server Error in /Project page from showing up?
Take the TripPriceService.wsdl from this link Add a service reference(ServiceReference1) to a windows application, by giving the wsdl from the mentioned wsdl file saved in local folder. My question has two parts
1) Is the below fault message a valid soap fault as per the wsdl(TripPriceServiceException)?
2)Now How to handle and catch the detail tag, when the response is a soap:fault?
Imports windowsapp1.ServiceReference1 Public Class Form1 Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim obj As New ServiceReference1.TripPriceServiceFacadeClient
[code]....
The line obj.getTripPrice, invokes the service. However will it throw an exception if the response is a soap fault(of type TripPriceServiceException)? How to handle such cases, do we need to use ServiceReference1.TripPriceServiceException? We are in a need to handle such faults in our webservice client.
I would like to turn of this exception in the debug menu but I am not sure how or which one to uncheck or check.."ObjectDisposedException was unhandled"
I'm creating a class library that contains a series of functions with Try...Catch blocks to handle errors. When i run another application that uses the class library, and call a function in the library using parameters that i know should cause an error (i.e. divide by zero), i don't get an exception thrown.
Can you not use Try.. Catch blocks in external libraries? If not, how are you suppose to handle errors in these functions?
I have a application in which dll of another project added,
In my dll's I have several exceptions defined, and when specific errors occur
I throw these exceptions with the assumption that the main application will catch and handle them if the DLL does not.
but when any specific error occurs in dll main application cant able to catch it and whole aplication get closed. i have added an snapshot which appears when any error appears in dll
how do i handle the exception raise in dll from main project
Is there a way to configure the debugger or write code in such a way as to get more information when first chance exceptions happen? I understand they are generally not harmful and I do quite a bit of exception handling in code but when I'm doing database operations it's to know when first chance exceptions occur. Of course I can see them in the Immediate Window in VS but I would like a full stack trace, not ust a line saying "A first chance exception..."
When an exception is thrown in my app, I expect the debugger to stop running and enter debugging mode, but it does not. Instead, I just get a message in the Immediate Window ('A first chance exception ...'), and the program keeps on running like if nothing happened. However, the sub (in which the exception was thrown) is exited, so statements after the exception are not executed. Since this sub makes the initialization of my program, running becomes very unstable.How can I tell the debugger to stop execution when an exception is thrown? On the 'Advenced compile options' page I don't have 'Target CPU'. Maybe it's that I have only VB Express?If I tick the 'Thrown' checkbox in Debug > Exceptions, execution stops even if I have a catch for that exception, and I don't want that.Until now I used VB 2008 on 32 bit, and everything worked fine, but since I moved to 2010 64 bit I just can't get it right.
I am catching sql exception from databse as shown below.[code]Now I want to throw exception by adding some userfiendly information,Like below.Throw SQLexception + "my message.....".
ll app build in VB 2005 that has a DLL. The app runs fine on 32bit systems but fails on 64-bit ones (Failed to load the assembly: BadImageFormat from the DLL). As I could not fix the problem I wish to somehow ignore this error so the rest of the app can run normally. I wish to retain the funcionality on 32-bit systems thus not removing the DLL from the project.
I'm practicing on this one, and I know it would be better to just use a string variable instead of a class. I have another working program using a string variable, but on this one I wanted to make it use an array of class objects.
I keep getting null reference exceptions at the line where the object is assigned the textbox text.[code...]
I have a silverlight application elevated trust deployed at my company and some errors I get the "debugging resource strings are unavailable" I was wondering if there was any way currently for silverlight 4 to get the full error message without installing the developer version of silverlight on every single machine.
