I have a question about how to properly deal with errors. I am working on a three tiered application. If an error is created on the data tier, I would like to pass the error to the business tier and process it there.What is the best method to accomplish this? I am using .net 2.0 and visual studio 2005.
View 1 RepliesWhy would my try-catch block still be throwing an error when it's handled?[code].......
View 8 RepliesCan someone please explain to me what this error means? I am new to VB programming and don't understand this. Error : Type 'var' is not defined
Here's my code
[Code]...
My code block is below. As it turns out, rdrCurrentRate.GetString(12) is a null value, but the code block throws an error. "Data is Null. This method or property cannot be called on Null values."My intention is to write "if rdrCurrentRate.GetString(12) is NOT NULL, then sCurrentRateType = rdrCurrentRate.GetString(12)"
What am I missing here?
If Not String.IsNullOrEmpty(rdrCurrentRate.GetString(12)) Then
sCurrentRateType = rdrCurrentRate.GetString(12)
[code].....
I cant see what is wrong with my SQL statement syntax [code]...
ERROR [42000] [MySQL][ODBC 5.1 Driver][mysqld-5.1.41]You have an error in your SQL syntax;check the manual that corresponds to your MySQL server version for the right syntax to use near 'Int,Agi,Money) VALUES('MyUsername','MyPassword',0,0,0,0)' at line 1
I'm passing in a sql command such as "EXEC StoredProc 0" into a a function called ExecMyCommand where StoredProc is a stored procedure taking a parameter of 1 or 0.It works fine with the following code.I had tried to judge success by looking at NumRowsAffected but soon realized that the -1 could represent a successful run even if -1 was the return value.So then I changed the code and return mLastRunOutcome = False if there is an error.So for testing I changed the name of the SP to like StoredProc2 in the database and ran the same command "EXEC StoredProc 0" and to my amazement, no errors were thrown in the code below..Of course ran the same command in Query Analyzer and it barked that there was no SP by that name.How do I know when a command ran successfully or not in code here? and Why didn't the ExecuteNonQuery throw an error when the command was not right??[code]
View 2 RepliesIs there a command that will stop the execution of my program?
I have a service that is processes an exchange account via telnet every 10 minutes. During one point of execution the application could possibly have a response from the telnet session when there are NO e-mails in the folder, which would look something like this[code]...
So is it possible for me to just stop my application at that point since there's no point in continuing if there are no e-mails in the account?
I am trying to read all selected items from a listbox in Visual Basic.
Dim x As Integer
Dim testValue As String
testValue = "20"
[code].....
When calling API's or other external functions it is only possible to get thrown errors using "GetLastError". I made the following function for this:
[Code]...
I'm developing a mobile website using vb.net but having set my tools right as I read somewhere, I've having an object reference...null error from the sqladapter line. I'm trying to authenticate by checking the db for username and password and granting or denying access asthe case maybe, [code]
View 6 RepliesI have been trying to assign value to an object array that is defined as follows.Dim englishTextAry As Object(,) = New Object(,) {}I am looping through a dataReader and trying to assign the values to this array with the following code.[code]But the ReDim is throwing an error on dataVal not being an Integer.What am I doing wrong here? Can anyone point me in the right direction?
View 2 RepliesI 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.
Number of downloads: 81This program is supposed to calculate the ever popular mortgage payment and amortize the loan in a list box. I keep throwing this error "Missing Member Exception" and can not find out how to fix it anywhere. Because of the error I can't even see if I can even get a calculation in the text box, let alone if the amortization will run. The purple text is where the exception is.
Public Class HarlessSmithIA3
Dim LoanAmt, Int, Result, Term As Double
Dim txtIntRate As New Object
Dim txtLoanAmount As New Object
Dim txtLoanTerm As New Object
Dim txtMonthlyPayment As New Object
[CODE]...
Source File: MathNet.dll
Output file: MathNet.tlb
Included Classes MathNet.Division and MathNet.Multiplication
[code].....
I'm tried to make a control that will kill itself when added to a form. Actually what I want to do is make a control that will ask for password before added to a form, and remove itself if the password is wrong... Anything work great, it really will remove itself from the parent form, but it will show a error message too: "'child' is not a child control of this parent."
Here the code:
Public Class SuicideCustomButton
Inherits Button
Protected Overrides Sub InitLayout()
[Code].....
I'm tried to make a control that will kill itself when added to a form.Actually what I want to do is make a control that will ask for password before added to a form, and remove itself if the password is wrong...
View 2 RepliesI am trying to have my .NET application interop with an object created in VB6. The VB6 application has a ShowDialog method with the following signature:
Public Sub ShowDialog (Optional fParent)
And inside the code, there is the following lines of
If Not IsMissing(fParent) Then
[code]......
I'm trying to make an MDI parent form to call other forms. I have put this code which I found in a post here into the main form which I added to my project as an MDI parent form:
[Code]...
I get an error message which say FrmEmbed is not defined. How can I correct this?
I have a window form with a parent shown as detail items and two child as datagridsviews. They work perfect when saving and uploading data. The problem arises when I up load a picture to a picturebox and I go to save. I receive error dialog "System data invalid constraint exception: FK WineList_WinePurchase requires the child key values(1) to exist in the parent table. Not sure what happening when I add the picture.
Private
Sub WineList_Load(ByVal sender
As System.Object, ByVal e
As System.EventArgs) Handles
[code].....
This is a challenging one that got me stumped while I was coding today. Suppose I am running the Sub Test1() and Test2() and would like to print out the value of the Shadows method of the instance of the object I am passing in to TestCall() (see below - it is clearer) using the following restrictions:
Can't change the contents of Class A, B, and C
Can't change Sub Test1() and Sub Test2()
TestCall() can't have an if, select case etc. statement that tries to figure out the type
[code].....
I have a main form, and some sub forms, and each sub form can have some sub forms. When I have multiple sub forms open, and I try to get data from the parent form, it returns the data from the wrong parent form.For example I have two instances of Mainform.subform running. If I do something like this in a child form of one instance of the subform. It returns data from the other subform.
dim l = Mainform.subform.listofdata
Edit:I am using visual Studio 2008. Winforms, form designed using designer. In my mainform I am doing this
Protected Friend frmMain as Mainform
frmmain = new mainform
In frmMain I am doing this
Protected Friend frmsub as new Subform'
frmsub = new subform
[code]....
I would like to know if there is some simple code to release a child control from it's parent control, without having to name the parent control. In pseudocode, I'm looking for something like this:
[Code]...
I have the following code:
[Code]...
I thought at first that because during testing GetFormsByStatus() returns 0 results maybe that was causing problems, but it doesn't make sense that Except() wouldn't work if the provided list had 0 items.
I have the following code:
Public Shared Function GetAvailableManufacturers() As List(Of Manufacturer)
'first get all the live orders and extract their mfrs'
Dim sos As List(Of OrderForm) = GetFormsByStatus(StockStatus.Building)
Dim unavailableMfrs As New List(Of Manufacturer)
[code]....
My idea to get available manufacturers was to get a list of all the manufacturers in my open forms, then get a list of all manufacturers and exclude all the manufacturers in the first list, illustrated like so (pseudo):
List A: {1,2,3,4,5,6,7,8,9,10}
List B: {5,7,10}
Result: {1,2,3,4,6,8,9}
I have set up my Manufacturer class according to this article so that it can be compared, but I'm still getting this error:
Unable to cast object of type '<ExceptIterator>d__92'1[csCore.Manufacturer]' to type 'System.Collections.Generic.List'1[csCore.Manufacturer]'.
I thought at first that because during testing GetFormsByStatus() returns 0 results maybe that was causing problems, but it doesn't make sense that Except() wouldn't work if the provided list had 0 items.
While I've previously many years of relational databases and procedural languages, I'm stumbling with Visual Basic. In this problem, the simple situation is that I have two files, parent and child. The primary key of the parent file (Area file) is linked by a relation to one of the two fields that makes up the primary key in the child file (Project file) (unique key is formed from 'area' and 'project'). I have the default table adapters created on both files. I have created two maintenance forms showing one each of the two files in datagrid view format.I can create some records in the Parent (Area) file, but when I try to create a record in the child (Project) file, using one of the valid key values from the Area file, I get the 'ForeignKeyConstraint [relation name] requires the child key values [actual value] to exist in the parent table' which I'm absolutely definitely sure it does.
I haven't done any actual coding for those two maintenance forms, just dragged-and-dropped the files from the data sources screen onto separate forms so it creates the controls itself. But I can't work out, if it already knows the data does exist because I can load it back in to the Area maintence form, why it can't check itself to find out the record does exist. Why does it think the record from the parent record doesn't exist? It does exactly the same thing, whether or not the database is in access or SQL Server Express. I have all the latest updates.
The following sub is throwing a"Object reference not set to an instance of an object."
exception.
For Each element As Song In modFiles.getSongs()
Dim col(2) As String
[code].....
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
I'm throwing an exception that looks like this...
View 3 RepliesNot sure if too many people know this, but the following line will cause an error:
GroupName.Substring(0, 3) = "jt_"
....if the length of GroupName is less than 3 characters. I always thought it would simply return whatever characters in GroupName, but no, it errors. I must be thinking of the old VB6 days.So, I now have to change the code to:
If (GroupName.Length > 2) Then
If (GroupName.Substring(0, 3) = "jt_") Then
Note that the two comparisons need to be on separate lines. If they are on the same line, such as:
If (GroupName.Length > 2) and (GroupName.Substring(0, 3) = "jt_") Then then the code will still fail as the length command is executed at the same time as the substring command- which will cause the error when the GroupName length is less than 3.Just thought that those of us not aware of this should be!
dp.SyntaxHighlighter.ClipboardSwf = '/dp.SyntaxHighlighter/Scripts/clipboard.swf'
dp.SyntaxHighlighter.HighlightAll('9844f9bfb55449e6a786fa62aaadfa20')
dp.SyntaxHighlighter.HighlightAll('f6d554fd98464bdba9159b319e51b381')
dp.SyntaxHighlighter.HighlightAll('93bf4ca63ad8447abdf084d8a9991e15')
I have an ASP.NET page with code-behind in VB.NET. On the ASPX page I have a Repeater with an asp:ImageButton inside the repeater and I want to catch the clicks on the button. As far as I read I have to use FindControl and then handle the copy of the original control:
[Code]...