Is the only way to create custom exceptions to inherit from System.Exception?
I wish to create a class that can be thrown as an exception but i do not wish to inherit from System.Exception because i have a base [Object] class in my library which all my classes should inherit from and i wish my custom exception class could also inherit from it.
Is there anyway to create a Custom Exception without inheriting System.Exception?
my reason is that they have a lot of methods which i do not wish my Class to have.
I Have just been watching a video on throwing Exceptions. Are you supposed to throw System.Exceptions from within your custom classes. to the calling code, Which other way can they communicate. I have read in several places it is bad practice to throw SystemExeptions.
View 3 Repliesi have a data set on the data set many data adapters .i add a data adapter in the data set the designer was automatically delete then lot of error was coming and i search in google and i go this method and i do that right click the data set and "Run Custom tool" on that time the designer will automatically created. but when i do that a error was coming "The custom tool 'MSDataSetGenerator' failed. Exception of type 'System.Data.Design.InternalException' was thrown."
View 2 Replies(using vb 2008 I am learning the workings of Custom Events. I think they might solve the problem of being unable to declare nonserialized events in vb2008. However, do custom events follow any sort of inheritance pattern like classes
View 4 RepliesIs this possible? Must be surely but I've tried and come up short. I've created a very basic class (person) with 2 public properties, forename, surname. My user control is databound to this class and has 2 textboxes to store the properties.
I've built the control and can add the user control to a windows form but how can I add to a new user control (Staff) which will show my 2 existing textboxes and I can add dateJoined datepicker also??
Is there a way I can catch and handle two different exceptions within the same exception type? For example:
Try
' My code
Catch ex As System.Net.WebException
End Try
I have 2 different exceptions that are System.Net.WebException. I want to handle them different ways. Problem is the catch block above catches them both. Is there a way I can determine if which of the two it is and handle them differently?
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.....".
View 8 RepliesI am trying to inherit System.Data, but when I use Inherits System.Data I get a "Type Expected" error. Is there a way to do this? or is the question I have been given meant to make me realise that it can not be done?
View 4 Replies[Code]...
Notice the catch (Type) instead of catch (Type myVariable). Is this possible with VB.NET, or do you always have to declare a variable when you catch exception types, like so:
[Code]...
All of us use the try catch blocks. But what is the best way of handling errors within custom functions?Display a messagebox to the user when the exception is thrown (if possible within the function), or return a value indicating that an error was found within the function?
View 3 RepliesI have written methods to override the LoadPageStateFromPersistenceMedium and SavePageStateToPersistenceMedium methods. now the problem is that i am using a masterpage, so how do i maintain using my masterpage and still inherit from System.Web.UI.Page?
Bear in mind that the .vb Code behind the masterpage already inherits System.Web.UI.MasterPage. Anybody know how i can "properly" override these methods in a MasterPage?
on the msdn pages describing classes etc, there are a lot of properties and methods mentioned from classes. But is there a kind of property of a class or method which gives te collection of expected errors ?i ask this because in the try catch statement you can specify the exceptions and errors you want to catch, but
View 4 RepliesIs there anything similar to the MyApplication_UnhandledException for an user control in VB?
I would like to have a central point where to catch all unhandled exceptions of a user control, without propagating the exception to the application that uses the user control. I made some test raising an exception in a method of my user control where there is no try/catch code (of course in the true project all methods have a try/catch block). The exception was caught by MyApplication_UnhandledException event of the application using the user control. But this is too "far" from the point where the exception happens and in worst case the user should restart the application.
I would like to realize a behaviour for the user control in order that if the user control fails, the exception is not propagated till the application, but just caught at user control level.
I would like to utilize classes that inherit the System.Data name space.Specifically, I would like to have classes CarColumn, CarTable, and CarSet derived from DataColumn, DataTable, and Dataset respectively.I would like to be able to add additional properities to each class. As an example this is how I would like to reference items within the classes:
CarSet.CarTable(0).Columns(0).foo
CarSet.CarTable(0).bar
I know that VB.Net is not capable of Multi-Inheritance.
So I've made this control that inherits from the treeview control and basically loads objects from active directory into a treeview (url...).All working fine, but as this is the first custom control I have made that I have intended for other people to use, I'm not quite sure how I should approach error handling.I mean, obviously I shouldnt do something like show any exceptions in a messagebox because that might not be what the person that is using the control wants to happen. So do I just write out exception messages to the debug window? Do I swallow exceptions (guessing not)? Do I just totally ignore them so that they are thrown in the user's project?
View 4 RepliesI'm getting 'Catch' cannot catch type 'Object' because it is not 'System.Exception' or a class that inherits from 'System.Exception'. and 'Expression detected' Code underlined in blue: Catch obj1 As Object When (?)
Private Sub OpenJAMem()
Dim num3 As Integer
Try
[code]....
i have about 20 possible exception messages that i want thrown when an error occurs.i need somthng like this when catching the exception
Try
' do domthing
Catch ex As CustomInvalidArgumentException
'do domthing
[code]....
do i have to create a class that inherits from Exception for each type of exception?
I never got into detailed error processing too much when I played in VBA/VB6 a lot. Mostly then, if you ran into a user error (such as some input of theirs failing a validation test of some kind), you popped a MsgBox() with some error information and the critical (or warning) icon, and safely aborted out of the code
In .NET, my reading basically points to exceptions as the end-all in error handling. It looks to me that if you know a spot of code where a user can screw up, you're supposed to catch it with either try...catch blocks (for things like data conversions), or standard if...the...else constructs for other things, and then throw a new exception if needed.
Isn't throwing an exception essentially a forced crash of a program in a sense (granted, you get the option of continuing)? Or are exceptions geared specifically for things like data conversion errors and other "things that shouldn't happen", and resume use of MsgBox() and friends for minor user screwups?
Consider the case of where you have a TextBox that is only supposed to accept numeric data (or heck, just a specific set of characters). Barring some other trick that lets you restrict that field (let's just assume it's freeform, programatically), it would seem a bit of a waste to throw new exceptions everytime they type in an invalid character, or even if the error checking doesn't happen until they press a submit button (like on a webpage). Popping a MsgBox() seems more sane in that case.
So what's the straight dope on exceptions and throwing new ones on user errors? How about if your program also exposes a programmatic framework? Bad usage of one of the programmatic functions definitely seems like new exception territory to me.
I have to create a new project and in that project I have to create a inherited form from an older project. When I choose an inherited form, it says that I only can choose a dll file. But in my older project there is only an exe file. In all subfolders I cannot find a dll file. Can anyone help me to create a dll file for the older project so I can inherit that file in the new project.
View 6 RepliesHow to create a class which inherits from a data type, specifically from Char data type? I just want to add one property to it. If it's not possible, are there any other ways to accomplish this?
View 2 RepliesI have a large project where we have 2-3 dll projects that are converted from VB6 to VB.NET. We have fixed all the issues that caused compilation errors, and most of obvious issues in running, so now we have basically a program up and running. The exe is created from scratch in VB.NET, using a lot of functionality from the converted dll's (including GUI forms). What I wonder is when I run the program in debug mode, I get a bunch of warnings in the "Immediate Window" saying:
A first chance exception of type 'System.Exception' occurred in Microsoft.VisualBasic.dll
...and some of other type (but most of them in Microsoft.VisualBasic.dll).I was wondering if this is common in projects converted from VB6, or if it is caused by bad design in our code...
I have a relatively simple VB.NET app. It targets framework 2.0 from Visual Studio 2010. The app works fine most of the time, except that the users sometimes receive the
following exceptions. The error is completely random and somewhat rare. I haven't been able to trap it while in a development environment. It also doesn't appear to be
pointing at my code. My app continues to run if the users ignore the error. How would I trap and handle this error?
I am cleaning up some code and I have multiple classes that are 99% exactly the same. So my understanding is that my options are...
1. Create a class and all other classes inherit from it and modify it a bit
2. Create an abstract class and all classes inherit from it and modify a bit ** I took this route
3. Create an interface and all classes Implement that interface.
Here is my 'original' class below (the one that all of them look 99% identical). This class is used in an arraylist so I have a listing of all my images from a folder I have searched.
[Code]...
I am using VS 2008, Office 2007, and Win7 Home Premium on my system.I have a simple application which should be a breeze to build. All I am attempting to do is pull data from an Access database with four small tables into a data grid on a windows project. Should be simple, set up the data connection, choose a datagrid from the table in the data source view, drag it onto the page and done, right?I can't get it to work. It will all work fine until I attempt to run or debug the project. The data will not show up. The data grid does, but I get this error: A first chance exception of type 'System.InvalidOperationException' occurred in System.Data.dll
As I said, the project seems to build fine, but it will not pull the data. After the initial build I get the message that Windows will show this page in Compatibility View. Is it something with Win7 Home Premium, or a setting somewhere?
I'm using express 2008 build the windows app. and in the app, it calls a webservice which was built by VS2003.It works fine on most PCs. however, there is one PC, it always shows this error:
System.TypeInitializationException: The type initializer for 'System.ServiceModel.ClientBase' 1' threw an exception
....
System.configuration.ConfigurationErrorException: Configuration system failed to initialize ---> System.Configuration.ConfigurationErrorsException:
Unrecognized configuration section system.serviceModel
.....
however, the configuration file was generated by express 2008, and it seems there is no error.
I would like to create a local user on a windows 7 PC, but gets the following error when commitchanges runs. I am administrator on the PC:
A first chance exception of type 'System.UnauthorizedAccessException' occurred in System.DirectoryServices.dll
Here is my code:
CODE:
I am using Visual Basic 2010 ultimate in Visual Studio 2010.
get out from the below loop
Shared Function GetIPAddress() As String
Dim sam As System.Net.IPAddress
Dim sam1 As String
[code]....
I have a program that creates a Treeview from information procured through an ODBC query and dumped into a dataset. I have three such queries set up via radial buttons as well as a refresh button that triggers whatever radial button is active at the time it's clicked. The purpose of this program is to allow drag-and-drop of selected nodes, ending with a post to the database that officially makes that change of assignment to the new node.
[Code]...
Here is the code I am working with, everything works fine up until last line then i get evaluate exception unhandled "Cannot perform '=' operation on System.Int32 and System.String." My eyes are going blind trying to figure out whats wrong, if I understand correctly it cant count system string and REO is a string value.
The thing i have done this before ,count that is. I know you cant average strings and some other function but i have been able to count.
d Dim comm As New OleDb.OleDbCommand("Select * From " & Me.OpenFileDialog1.SafeFileName & " Where Status <> 'S'", con)
Dim dalist As New OleDbDataAdapter(comm)
Dim comm1 As New OleDbCommand("SELECT * FROM " & Me.OpenFileDialog1.SafeFileName & " Where Status
[CODE]...
