I have a form where it is validating three fields. I want to have it so if an exception has been thrown in any of the three fields that the code that is in the button does not run and it redoes the validation.
View 4 RepliesWhat types of exceptions should be thrown for invalid or unexpected parameters in .NET? When would I choose one instead of another?
Follow-up:
Which exception would you use if you have a function expecting an integer corresponding to a month and you passed in '42'? Would this fall into the "out of range" category even though it's not a collection?
I've a control that throws an exception in one of its events and I need to catch this exception. How can I do this?
Example:
Private Sub AxNtlxImage_Reason(ByVal sender As Object, ByVal e As AxNTLXIMAGELib._DNtlxImageEvents_ReasonEvent) Handles AxNtlxImage.Reason
' TODO: Deal with this reason message
Throw New ArgumentException(e.sText)
End Sub
I want to catch this exception from another procedure when it happens.
I'm using Vista Ultimate x64 to develop on and I have found that any unhandled exceptions that I would expect to get thrown in the Load event of a form do not actually get thrown... This happens no matter which compile mode I select (x86, x64 or AnyCPU). If I copy the exact same EXE to an XP machine then the unhandled exception is thrown as expected and the JIT debugger warning message appears. Its very annoying as absolutely no indication that an exception has occurred is shown, the program just loads normally but anything after where the exception should have been thrown is not executed. For example, if I create a new project now and stick this in the form load event then the program would just load as if nothing has gone wrong:
My.Computer.FileSystem.ReadAllText("----")
In my project, I have a local dataset (XSD) that I am using as local-temporary tables. I am getting a System.InvalidCastException when trying to access the field in one the tables. I believe this is because I my code is (incorrectly) not setting a field's value in a row before trying to access it.My problem is that the exception is breaking in the designer file and not in my code. As a result, I'm having difficulting determining which line of my code reading the field value before it has been set. Is there any way to configure Visual Studio to break in my code instead of in the designer created file?
View 1 RepliesThis may be a debugger issue, but here goes:I have this piece of code:
Private Function Connect() As Boolean
Try
sessionBegun = False[code].....
My intention is to 'convert' the low level exception into something more meaningful, so I throw an exception of my own creation. I want this to bubble up to a place where I can handle it.However what is happening is my debugger breaks and tells me that an exception of type "QuickBooksConnectionException" was thrown.I know that, I just threw it, why are you catching it? From what I've read, this ought to work, and there doesn't appear to be an analogous Java throws keyword, so perhaps it is my debugger.
I have a tab control that I would like to set the background image of each button's interface to the same image. I set the color to transparency and set the background image, but the background image only works on one button's interface.
View 1 RepliesI am making a program that calculates various results with variables entered by the user. What I am trying to do is incorporate a function that will allow the user to switch from metric to imperial easily but only when the ok button is pressed. Now I got all the coding done for the metric and everything is working fine. My problem is when I use the radiobuttons to switch the entered variable in the text box to the desired unit it gives me a 0 or a random number in the textbox...
I also have labels indicating each variables unit which I easily managed to change with the text box using this code. :
'Change Labels to Metric
lblMDegreeC.Text = "Degree C"
lblMDegreeC2.Text = "Degree C"
lblMmm.Text = "mm"
lblMmm1.Text = "mm"
lblMmm2.Text = "mm"
lblMm.Text = "m"
lblMm2.Text = "m"
lblMm3.Text = "m"
lblMDegreeC3.Text = "Degree C"
I created all the coding to convert the metric variables to imperial. My problem is changing the textbox text when the user switches the units during run time. The labels change without a problem but the textbox never works. I have attached the coding for the file.
I have a function that is exported by a C library with the following signature:
extern "C" BOOL Func()
The function is declared in VB.NET code like this:
<DllImport("mylib.dll", CallingConvention:=CallingConvention.Cdecl)>
Private Shared Function Func() As Boolean
End Function
The problem is that I get an ExecutionEngineException when I call the function from .NET code.
Given that BOOL is typedef'd as int in this C code, should the declaration be different? If so, how should I be declaring this? As Short or Int32? Do I need to marshal the return value?
lets just go straight to the code:
View 3 RepliesI'm encountering some rather strange behavior in the VB2008 IDE regarding exceptions. I tried to explain what I need as best I can in the title, but I'm not sure there's a succinct way to describe it.I'm not the best programmer in the world to say the least, so sometimes I do things that generate exceptions when I try to run them (This is why we test things continually, right?). Typically, in addition to the Exception Assistant popping up and giving a suggestion, the IDE highlights the code that caused the Exception in the Code Window.
Well, today I went back to a project I had been working on after putting it on hold for awhile, and while the Exception Assistant still pops up when there's an exception, the IDE doesn't auto-scroll and highlight the offending code anymore. I have no idea why it does this, nor do I know how to fix it. Resetting settings from the Import and Export Settings Wizard didn't fix the problem, and neither did trying to reinstall VB2008. Is there some setting, obvious or otherwise, that would cause this?
I am attempting to use the VB.Net Excel COM interop to programmatically change the location of the first horizontal page break on an Excel spreadsheet being generated by the program. Code to do so is as follows:
Dim range As Excel.Range
xlActualWS.Activate()
xlActualWS.PageSetup.PrintArea = "$A$1:$K$68"
[code].....
When two computers are connected through TCP, and one of them closes and breaks the connection, it throws error 10054 "Remote host forcibly closed the connection".I want to handle this error because I know it will happen more often than not with the application I'm building. In System.Net.Sockets.SocketException, there is an on the error code. But when I run the program, the exception that is being thrown is System.IO.IOException, and the GetType for IOException is the socket exception. I don't know how to handle the socket exception if it's not the root cause of the exception.
Here is the code for my Try Catch block:
For infiniteCounter = 1 To 2
infiniteCounter = 1
[code].....
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'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?
View 1 RepliesNormally, i don't get this error while open form design. But I am ALWAYS get this error, when i worked on my project apx. 30 minutes.
When i get this error, i close my project, and reopen. then this error gone... "view designer" work normally and open my form. I have got 4GM ram,and when i get this error,my used ram is 2.5 gb. I am using VB.net 2008.[code...]
I believe there wont be any diff if user clicks the button on the form and the click event is fired OR if we call the button click event / function in the code. Because in one my project, this does make diff. If I click the button on the form, the App works great but same button if I click it thru the form code, the whole process crashes. This happens in Vista / VB.net.
View 12 RepliesI have made an application in VB.NET.The Button click codes are working fine. I have made a small modification in the code. I have commented the line 'Me.Close'But still my form gets closed. I think the application is executing from elsewhere.
View 8 RepliesI am using ASP.NET 3.5.
I have a button called btnSubmit and on this button in the PostBackURL i have a URL the page must submit data to.
<asp:Button ID="btnSubmit" runat="server" Text="Submit" CssClass="Hand"
PostBackUrl="http://now.eloqua.com/e/f2.aspx" />
Now when i have this i cant excecute more code in the button click event like so.....
Protected Sub btnSubmit_Click(ByVal sender As Object,
Dim name as String
name = "HELP"
End Sub
Why is this and how can i do a PostBackURL and still excecute code when the button is click?
Note: The Postback URL is located at another compnay who will capture the data
I'm wondering if it is possible to write the code for the button so that, when pressed by the user, it would add whatever text is in the text box to the list box and change the code of the form load to add that text to the pre-existing listbox.items.add's that are in the code of the form load.
View 2 RepliesI have one radio button and one listbox .i want code for display listbox depends on the radio button check true and false.
View 3 RepliesI'm making a VB.net application. I have a dialog that pops up at some points. It is set as TopMost. The problem is, when it pops up, you can't move the main form. How can I make it so it shows and is usable while allowing the main form to continue to be usable?
View 1 RepliesI'm a learning VB.NET programmer that just ran in to some trouble. I'm creating a TCPClient/Server chat room application. When a client connect to the server, the server creates an object that represents the client and stores the reference to this object in an ArrayList. This "IndividualClient" object begins listening for messages, just strings, from the actual client program using a new thread that runs NetworkStream.Read. Now, when the client program is closed, the server-side IndividualClient object is supposed to throw an IOException at the NetworkStream.Read method, but this exception is never thrown, and I'm not able to catch it and handle the disconnecting of the client. With the client not disconnecting and never being removed from the ArrayList, all kinds of problems start to arise when the server tries to send a message to all connected clients.[code]
View 4 RepliesThe Exception is not thrown in the following code in Visual Basic 2005, if sqlserver 2005 is down.[code]...
View 12 RepliesUPDATED: Feel like this shouldn't be that complicated, but I think I just don't know the proper name for what I'm trying to do. I'm dealing with an ASP.net project. The concept is pretty simple: I have a library that supplies some ecomm functions. One class in the libary contains functions around calculating tax. One class in the library revolves around the cart header. This class is consumed by a web project.
[Code]...
I coded my textbox to be only type in numeric numbers. But the backspace doesn't work when I run the program anymore, Can't delete what has typed in the textbox.
Here is my code
Private Sub AmountTextBox_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles AmoutTextBox.KeyPress
Dim allowedChars As String = "0123456789"
[code]....
I am creating a converter program (lengths, weights and such), basically just for the learning process because I still find myself very new to this.Well it's like this, I have a textbox where the user is supposed to write the value of the unit he/she wants to convert. As we all know there is a possibility to write in many weird strings which the program later on result in a big error. I recently managed to get rid of dots, because the program couldn't convert if there were a dot among the numbers "." (commas "," works great!). And now there are other types of errors I need to get fixed. I will make a short numeric list.
1. I wonder if it's possible to make dots "." to mean the same thing as a comma ",".
2. I also wonder if i could disable letters a-z or like -#@%&]?! and so on, i just want the basic 0-9 with a coma or dot.
3. I tried to make a Msgbox that tells the user when he/she has done an overflow, a number to big for the program to handle, for example [Observe the code is also trying to prevent the user from writing a minus "-":
(textbox1_textchanged)
If TextBox1.Text.Contains("-") Then
TextBox1.Text = TextBox1.Text.Replace("-", "")
[code]....
The minus thingy works great, but the 9999999... code, it always creates problems so I have commented it out for now until I know how to handle it.
4. Even though I got rid of the dot "." problem, the user is still able to write more then one comma, and I also want to get rid of that. The code I use right now for the "disable dot problem" is:
(textbox1_keypress)
If e.KeyChar = "," Then
If TextBox1.Text.IndexOf(",") > -1 Then
[code]....
I can't find a basic thing: how to enable a picturebox to be dragged inside a form? I'd need to be able to drop it inside a listbox so that listbox would get the picturebox's name-value in it. But I'm having trouble even getting started.
View 4 RepliesI have a textbox and I need to restrict entry to only the letters A-Z , a-z and the space key. I know I need to use something like
If (Microsoft.VisualBasic.Asc(e.KeyChar) < 65) _
Or (Microsoft.VisualBasic.Asc(e.KeyChar) > 90) etc
with an e.handled at the end
i would like to allow the user to play around with the size of the trackbar in vb.net. is there an easy way to do this?
View 1 Replies