I am trying to understand why the two code samples behave differently. I always believed the If() function to mimic the If language feature. Or am I looking at a behavior of Nullable(Of Integer) that is causing this?
Sample #1:
If Not String.IsNullOrWhiteSpace(PC.SelectedValue) Then
Dim pcFilter1 As Integer? = CInt(PC.SelectedValue)
Else
[Code]....
I would expect the following vb.net function to return a value of Nothing, but instead its returning a value of 0.
[Code]...
I wonder if this is not possible dim mystring as string="1" dim myint As Nullable(Of Integer) myint=0 myint=mystring It crashes on the last line why is that? mystring is already integer (1) , i dont have to cast using cint, i thought. option strict off- if this cause the problem
View 7 Repliesdim val1 As Integer? = If(5 > 2, Nothing, 43)' val1 = 0 dim val1 As Integer? = If(5 > 2, Nothing, Nothing)' val1 = Nothing What gives? Is this a bug, or am I overlooking something?
View 1 RepliesI've been pulling my hair out over some unexpected behavior from nullable integers.If I set an Integer to Nothing, it becomes Nothing as expected. If I set an Integer? to a String that is Nothing, it becomes 0! Of course I get this whether I explicitly cast the String to Integer? or not.[code] Previously I had my code up here so without the explicit conversion to Integer? and everyone seemed to be fixated on/confused by that. There were a lot of suggestions that Option Strict On would catch this type of thing. However, this is actually a quirk of the string-to-integer conversion rules which predate nullable types, but still impact them.
View 2 RepliesIf you assign a value to a nullable integer via a ternary operator, it can't become null..While this question may seem like a duplicate of many, it is actually being asked for a specific reason.Take this code, for example: Dim n As Integer? = If(True, Nothing, 1) In that code, the ternary expression should be returning Nothing, but it's setting n to 0. If this were C#, I could say default(int?) and it would work perfectly. Now it looks like I am going to have to ditch the ternary and use a regular If block, but I really want to use the ternary. If Nothing were truly VB.NET's equivalent to C#'s default, how can you explain this behavior?
View 1 RepliesI've tried these two blocks but it returns the same value. I do not describe more, I simply just show the code:
Dim f As Nullable(Of Integer)
If f = 1 Then
Console.WriteLine("Equal")
[Code]....
It works in C# correctly...
How can I create a nullable numeric optional parameter in VB.NET?
View 3 Repliesi want to build a datatable where each cell has a list(of integer)
is there a way to force the table to add automatically a new empty list(of integer) in each cell every time a new row is created without adding this cell by cell ?
Error1 Too many arguments to 'Public ReadOnly Default Property Chars(index As Integer) As Char'.K:\VB\Chap06\SumOddEven Solution\SumOddEven Project\Main Form.vb2645SumOddEven Project
Private Sub calcButton_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles calcButton.Click
Const prompt As String = "please enter even and odd numbers click cancel to end"
Const Title As String = "odd & even Number"
[code]....
i get this error?
' Create the order and store the order ID
Line 175: Dim orderId As String = ShoppingCartAccess.CreateCommerceLibOrder(shippingId, taxId)
[code].....
I see some functions within some code that are:
Public Function GetDataObjects(Of Customer)(ByVal dataset as DataSet)
...
End Function
What exactly does the (Of Customer) do in this instance or mean?
I need top create a function that gets the next integer in the sequence of 1 to 60. Each time the function is called, I need it to increment from what the last value was and return the next number as the result. It also cannot return the same integer in 2 consecutive calls. When the count gets to 60, the sequence needs to reset back to 1. I would like to function to have no parameters.
I have created a function that does this using the cache to store the last value that was returned, but I am worried that with concurrent calls to the function that it might not work as I expect and 2 calls could get the same integer.
Is cache blocking the correct method to use in this instance or is there something other method I am not thinking about?
Also, stuck using .Net 3.5 and this is a web application.
I just wrote this function based on using SyncLock. Any obvious problems with it that I don't see? I am using the Cache to save the last value that was returned.
Private Shared Function GetNextNumber() As Integer
Dim o As Integer
Dim r As Integer
[Code].....
I am doing a project.."Some Password". the criteria is that the password should have 1 numeric and 1 non numeric and atleast 6 characters. The code I worked on..(below)
Function CheckPass as Integer
Dim
blnContainNumber As
Boolean
Dim
blnCotainNonNumeric As
Boolean
[Code] .....
When I compile this code...it gives me a Messagebox error that I wrote.."Password Invalid" even though I type the password that meets the criteria. I think the problem is that I don't have..."if atleast one numeric then" and "if atleast one non numeric then"...
I don't think I fully understand passing values from a sub to a module. Here is what I'm trying to do (problem is at the '****):
[Code]...
I think I've seen something like this before - where the actual function returns a value. Is this possible? Or would I have to pass an integer variable from the sub to the function, and then return it back to the sub?
I'm trying to write a function that will return a dataset and an integer, is this possible?
View 1 Repliescoding a shipping application where it adds .75 for every 100.00 dollars it would look something like this
0.00 to 100.00 = .75
100.01 to 200.00 = 1.50
200.01 to 300.00 = 2.25
300.01 to 400.00 = 3.00
and so on where the equaled value goes up .75 everytime i think i could use integer division and/or modulus
i want to know what is the default type of function or method declared without public,private,friend,protected,protectedfriend keyword
View 3 Repliesits just like that in other langauges (php in the example)
function myFunction($message,$sender="nodoby") {
return $message." by ".$sender;
}
is there any VB.Net existing saving function?
View 7 Repliesin my following code, i get the warning doesn't return a value on all codepaths
Public Function getbacktrace(ByVal backtrace As Integer) As StackFrame
With New System.Diagnostics.StackTrace()
If .GetFrame(backtrace + 1) Is Nothing Then
exit function
[code]....
if i change exit function to return new stackframe,anyway, why doesn't Exit Function automatically returns a "dead" stackframe?
I have a public function declared in my code-beside on default.aspx.vb. I needed to add a second page to my project and copied and pasted that function into the second page, but when I test the page I get an error saying there's a conflict with the same public function on the default page.
If I remove the function from the second page, i don't get the error, but will it still be accessible if called on that page, even though it's on the default page? Or do I need to place it somewhere else so that it's accessible to both pages?
I'm writing this program to determine deterioration after X amount of years and i keep getting that same error.ive tried redetermining and revaluing variables.
Public Class Form1
Dim Anldep As Double
Dim endval As Double
[code]....
Can a function return a value byref instead of the default byval? That is to say, allow me to directly edit the variable that it is retrieving instead of just giving me a copy of that variable.Right now I'm trying to write a function that will return, based on what the user has selected through a combobox, a particular setting (eg. My.Settings.somethingHere). I then want to be able to edit the setting directly through just calling the function. Is that at all possible?
[Code]...
This function doesn't work if I change the input argument 'pdu' from a string to an int.Would someone please help me figure out what to do here so that the checksum does not add the ascii value of the int argument but rather the actual integer value?I took out a few lines of the actual function but it adds the input argument to a packet sent out via TCP protocol.This function shows the integer value just fine in the string that gets encoded as a byte array. the checksum is wrong.!
''Public Function buildpacket(pdu As Integer) is what I want.
Public Function buildpacket(pdu As String)
Dim packet As String
[code]....
I am very confuse over a Raise Events example and using delegate as a function pointer: I am clear with this function pointer example program below which creates a generic sort function for sorting integer arrays without changing the main sort function.
' Returns True if need to swap
Delegate Function CompareFunc(ByVal x As Integer, _
ByVal y As Integer) _
As Boolean
Here are two alternative target methods for the delegate - one for an ascending sort and one for a descending sort:
Function SortAscending(ByVal x As Integer, ByVal y As Integer) As Boolean
If y < x Then
SortAscending = True
End If
End Function
Function SortDescending(ByVal x As Integer, _
ByVal y As Integer) As Boolean
[Code] .....
I have a whole slew of database access functions which assume a particular connection string. Within my application I call
[Code]...
My problem is this (apologies if this is a little long ... hang in there):I can define a function in VB.NET with optional parameters that wraps a SQL procedure:
Sub Test(OptionalByVal Arg1 As Integer _
Optional ByVal Arg2 As Integer _
Optional ByVal Arg3 As Integer
[code].....
i'm accessing an access database and want to execute the following query
INSERT INTO sometable
(date, field1, field2)
SELECT ( ? AS Expr1, field1, field2)
FROM othertable
? is a date i generate in code and field1,field2 belong to othertable i put it in a tableadapter and execute it by me.tableadapter.queryname(calculated date) but i get the error : Too many arguments to 'Public Overridable Overloads Function queryname() As Integer' Also if i try to generate the date in the query builder in the form dateserial(year(now),month(now),1-1)the query builder does not accept it?
I'm following this tutorial: [URL]..except I'm connecting to my own data source - a MS Access database.This is the query I have setup with the dataset:
SELECT Terminal_ID, SUM(Transaction_Quantity) AS Total
FROM tblTransaction
WHERE TransactionType_ID=3 and Transaction_DateTime>[@fromdate]
GROUP BY Terminal_ID
The debug fails immediately because it needs the extra parameter so I change the code from:
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'TODO: This line of code loads data into the 'tetrisDataSet.tblTransaction' table. You can move, or remove it, as needed.
Me.tblTransactionTableAdapter.Fill(Me.tetrisDataSet.tblTransaction)
[code].....
The error I get on build is:Too many arguments to 'Public Overridable Overloads Function Fill(dataTable As tetrisDataSet.tblTransactionDataTable) As Integer
...I gave it the extra parameter, so what gives? Something special I need to do as it's a datetime field?