[2005] Throw Exception - Used Methods From Namespace System.IO
Mar 12, 2009I want to throw error, if i used methods from this namespace System.IO
For example,
If i write File.Delete("TempPath") , i have to throw undefined Method..
I want to throw error, if i used methods from this namespace System.IO
For example,
If i write File.Delete("TempPath") , i have to throw undefined Method..
I have a number of very useful extension methods that I'd like to use in my Silverlight project.I've pasted the Module here [URL]The problem I'm having is that visual studio complains that the dlls my module have been written against have not been built against the Silverlight runtime.Is there an easy way to get these extension methods working in Silverlight?I'm thinking my main hurdle is getting IObjectSet and ObjectContext to run against the Silverlight run-time - perhaps there's another way to expose these methods that I'm not aware of.
View 1 RepliesWhen I print to the printer, using the PrintDocument, I want it to be able to throw an exception if there is a problem. Currently, if I print to a printer that has a jam, is offline, or doesn't even exist, VB still thinks it printed fine. I never get an error. How can I have the printer report back to my program so that if I print to a printer that doesn't even exist, it wont let me do it? I just tried adding a LPT1 printer to my computer (and there is no local printer). I called it some random printer and installed some random driver. Then used my program to print to that printer and never got an error.
View 1 RepliesIt is possible to catch an exception and throw a new exception which wraps the first exception as an inner exception: [URL] Also, if I call a function and it throws a certain error, but I catch it, will the calling code's catch handler execute? If so, and it is of a higher exception type, is this not wrapping the exception? eg I can throw exception ex of type IndexOutOfRange, log it but rethrow, catch a higher up exception and do something, or I can throw a new exception and wrap an inner exception like:
View 1 RepliesI have a project that I am working on and I just recently transfered it from an XP machine to a Windows 7 machine. Both machines are running VB Studio and the only thing that changed was I moved it from the XP machine to the WIndows 7 environment. I have not changed any of the code, I just transfered it and ran it to make certain nothing happened.
View 9 RepliesI am creating class libraries in my project so that I can update code without having to update the whole app.I created a class library project and added some code to it. I also added a reference to System.Data.SqlClient and also imported it into the class file.I am getting an error and I have never seen it before. Been looking online and not able to find an answer yet.
View 2 RepliesHere is the stack trace:
2012-03-16 19:15:09Z E System.NullReferenceException: Object reference not set to an instance of an object.
at System.Timers.Timer.set_Enabled(Boolean value)
at System.Timers.Timer.Stop()
Here's the code:
Timer declared as private member variable.
Private _myTimer As System.Timers.Timer
Initialize timer method.
[code]....
The timer has to have a value or else the Timer.Stop() call would be throwing the exception. This is a sporadic error and I'm just trying to see if anyone has experienced this before or if anyone has any ideas of what could be causing it. It is occuring in a WinForms application in the event handler for the Elapsed event of the Timer, but it is only occuring sporadically on the users computer. I haven't been able to reproduce the error myself.
I ran into an interesting dilemna today. I have a function that handles information and checks for duplicate values, then returns the next number that is not a duplicate. So, I have something like this:
Public Function GetNextNonDuplicateNumber(NumberToCheck as Long) as Long
//the non-duplicate the function will return
Dim NonDuplicate as Long
'duplicate
If CheckForDuplicate(NumberToCheck) = True Then
Throw New DuplicateException()
[Code] .....
As you can see, I want to handle the exception specifically, but I also want to throw it when I'm done because I want to alert other code outside the function. The problem is that simply throwing it exits out of the function with a null value.
1) How is ON ERROR GOTO -1 used? I don't understand the help text.
2) ON ERROR seems to be deprecated. What is the recommended Try...Catch replacement for ON ERROR RESUME NEXT. ie. where I have a series of commands, any of which may throw an exception, and I want to ignore all exceptions yet attempt every command?
I have written a VB.NET 2.0 code and in my code i am calling class.Showdialog and for that i am getting thread exception. I have mentioned the call stack of the exception. Can any one help me out to resolve this issue. [code]
View 5 RepliesThe type or namespace name 'Messaging' does not exist in the namespace 'System' (are you missing an assembly reference?)
View 2 RepliesAssume you have the following code:
Instead of doing:
Try
'
[code].....
while my first .net steps I want to understand and test the Method
Private Sub MyApplication_UnhandeledException in ApplicationEvents.vb.
But if I throw an exception the IDE stops and says "unhandled exception" and gives solution tips.
Is it possible to switch off those exception warnings and run through the unhandeled exception handling in ApplicationEvents.vb ?
I'm not getting any errors, or anything I just forgot how to do error checking in the "set" portion of properties
I have 3 Classes, my frmMain,Sales and a Validator Class
Code for the Validator Class:
CODE:
Code for my Sales Class:
CODE:
I need to Throw an Excepton when the Sales price is Zero or negitive and when the trade in allowance is negtive I'm not quite sure how to do that in the Object Oriented Manner.
If I have an existing exception object (I'm not in a catch block, I just happen to have been given an exception object), is there any way (re)throw it while preserving it's stack trace?
The context for asking is that I'm writing a RunWorkerCompleted handler. If an error happened while running the background task, then this will have shown up in the Error property of the RunWorkerCompletedEventArgs. To keep the code simple I want to use the same error handling code to trap this, or any error that happens later during the handler. That means I need code like this:
Private Sub OnDone(ByVal sender As Object, ByVal e As RunWorkerCompletedEventArgs)
[Code]...
I don't think that using an InnerException here (ie. saying something like Throw new Exception(ex)) will work because then I have the problem that my Catch block has no way of knowing whether the exception it's supposed to be handling is the outer one or an inner one. StackOverflow seems to have various similar questions, but I've not found anything that describes this particular situation.
This class is located in the namespace Acme.Infrastructure.Interface.A class with the same name EventArgs exists in the System namespace.In another project in my solution I have a class Acme.BusinessModules.MyModule.MyClass.When attempting to use the EventArgs class I have to fully qualify the class name or the compiler thinks I am using the System.EventArgs class.My understanding of namespace resolution was that the compiler would first look for the class in the current namespace, and then its parents. It seems that the compiler checks in System before it checks in sibling namespaces. Is it correct that System is checked before the sibling? Or is this behaviour caused by other issues (Imports order?)?
View 1 RepliesHaving problems with null dates in a mysql table. Have eventually found out that I can store a 'null' date in mysql as "0000-00-00" and I can run the 'insert' command to add a record to the mysql table. When I check on mysql workbench I can see the row has been inserted correctly and the date shows as "0000-00-00".However...When I try to load the table into a datagridview, I get an error = mysql Conversion Exception was unhandled = "Unable to convert MySQL date/time value to System.DateTime".
View 4 RepliesIs there a simple way in vb.net to mask a public property or method from the internal namespace? It would be helpful as a refactoring tool to isolate internal dependencies and perhaps to enforce a non-recursion policy for external services.
View 2 RepliesI'm getting an "Unhandled exception of type'System.MissingMemberException' occurred in Microsoft.VisualBasic.dll" error in this line of
oAppt = oApp.CreateItem(Outlook.OlItemType.olAppointmentItem)
The error message has additional info of:
Public member 'CreateItem' on type 'MailItem' not found.
Code in trouble is:
Private Sub Startup()
Dim oApp As Outlook.Application = New Outlook.Application()
Dim oNS As Outlook.NameSpace = oApp.GetNamespace("MAPI")
SubTwo(oNS, oApp)
End Sub
[CODE]...
The last line of pasted code is where the problem occurs. It was working previously but I'm trying to "modularize" my application by breaking the program into more manageable sub routines... this is a stripped down version of the code I have.
When I attempt to open forms in the designer in the IDE, I get this error:
Exception of type System.ComponentModel.Design.ExceptionCollection was thrown.
My project is building OK. Any ideas?
Why does System.Xml.XmlDocument.LoadXml method throw System.Net.WebException ?if MSDN was right, LoadXml should at most give me a System.Xml.XmlException.Yet I have weird exceptions like:The underlying connection was closed: The connection was closed unexpectedly.
Dim document As New XmlDocument
document.LoadXml("<!DOCTYPE html PUBLIC ""-//W3C//DTD XHTML 1.0 Transitional//EN"" ""http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd""><x></x>")
MsgBox(document.LastChild.Name)
I want to know what are classes , objects , a namespace , subroutines,functions,methods,properties and differemce betweem byval and byref in your words.
View 18 RepliesI want to check if an IP address can be resolved to a hostname.I figured I would use System.Net.Dns.GetHostEntry as System.Net.Dns. GetHostByAddress is shown as obsolete in VS2008.
However,if I specify an invalid IP address to System.Net.Dns.GetHostEntry the HostName property equals the IP address I gave. If I use System.Net.Dns.GetHostByAddress it, rightly, gives a resolution error.I don't mind continuing to use System.Net.Dns. GetHostByAddress but is there any way to have System.Net.Dns.GetHostEntry throw an error if the IP address cannot be resolved to a hostname (other than by checking if the IP address given equals the hostname returned, I mean)
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 would use the System.Linq.Dynamic. I added the specified Dynamic.vb file, that starts like this:
[Code]...
to my (VB.NET)solution. Now Visual Studio does not recognize anymore in the project files the System.XXX references, proposing me to change them to Global.System.XXX
I'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 below program that throw exception. Do you know how to fix??
Dim conn As New SqlCeConnection
conn.ConnectionString = "Data Source=" & Dir & StockTakeFile & ";Persist Security Info=False"
conn.Open()
Dim cmd As New SqlCeCommand("select * from TableStockTake", conn)
Dim reader As SqlCeDataReader
reader = cmd.ExecuteReader()
[Code]...
If I throw an exception from within a catch, does the finally (from the catch) still execute? i.e.
Try
..some code with an exception in it...
catch ex as Exception
throw new SpecialException("blah blah" & ex.Message, ex)
[code]....
I 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'm writing some code in which I need to use my own HttpResponse object to capture the output from a method on another object that takes an HttpResponse as a parameter. The problem is, this other object (which I cannot modify) calls HttpResponse.End(), which causes an "Object reference not set to an instance of an object" exception to be thrown. What can I do about this?
Dim myStringbuilder As New StringBuilder
Dim myStringWriter As New IO.StringWriter(myStringbuilder)
Dim myResponse As New Web.HttpResponse(myStringWriter)
[code].....