I am new to VB.NET but used to write a lot of code in VB 6.
How do i declare a variable length array in VB.NET?
In VB6, i would just put:
Dim sArrayList() As String
But when I do that in VB.NET, it highlights my array name and says "unused local variable". What do I need to do to get it to work without an error?
How do I declare a fixed length variable arra
Structure MyInformation
<VBFixedString(4),System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.ByValTStr,SizeConst:=4)> Public ReturnStatus As String
[code]....
I'm trying to call the GetInterfaceInfo Windows API - it accepts a structure as one of its parameters and this structure has a member that is an array. The API populates the contents of the array when it is called and there can be any number of items in the array. How can I define such an array in my structure?
If I just use a normal .NET array like so then the program just crashes (no exception thrown)
<StructLayoutAttribute(LayoutKind.Sequential)> _
Public Structure IP_INTERFACE_INFO
Public NumAdapters As Integer
[Code]...
and this works fine, but the problem is I have to define the SizeConst attribute as you can see to something large (64 in this example) so that the API doesnt fail because the array wasnt big enough. Firstly this is a waste of memory as in most cases the number of items the API sticks in the array will be less than 10, but secondly if there was ever a case where the API wanted to put more than 64 items in then it would fail.
Using ReDim to set the length of the array at runtime seems to have no effect, and that SizeConst attribute has to be set to a constant value so there's no way I can dynamically set it.
I have 2 arrays X(n) and Y(n). I would like to pass them between subroutines:
Sub sub1()
...
call sub2(X,Y)[code]...
The problem comes when n can be changed in sub1 say a textbox. How do you transfer an array of variable length between subroutines?
I have a problem when debugging a code. On top of class I declare an array, and the length of array is an integer variable which is applied value below declaration of array.
E.g. class declaration
Dim array1 (2, integer) as string
Public Sub
integer = 5
End Sub
So basically, array is created with integer being 0 or whatever, because it is declared before integer was assigned a value. But the problem is, I need it to be declared at class variable so I can use array in different subs.
What is the difference between using the 'array' class in VB and just declaring an array like normal. In other words, what is the difference between:
Dim numOfTicketsPerDay As Array
Dim intNumOfTicketsPerDay(6)
As Integer
Is there any preference of when one should be used over another?
Trying to declare some arrays. I haven't worked with them that I remember. I always took the long road, of declaring each and every variable, but would like to learn this method. The problem is I'm having trouble with the methods I'm finding on the net..[code]for some reason there is a squiggly under each MonsterName except in the declaration that says "declaration expected"
View 16 RepliesWe can declare a byte variable like this, for hex '88'
Dim bytes = New Byte() { &H88 } My case, 88 is assigned to a variable, hexvalue
How to declare the byte with the variable hex value?
Dim bytes = New Byte() { &H & hexvalue }the above throws syntax error.
I'm trying out a program which I found on the net. Why is it necessary to put to curly braces at the end of the statement? It gives an error: "Byte has no constructors". Dim data As Byte() = New Byte(1023) {} I can't put the code like this either, it produces the error "byte cannot be a 1-dimensional array".
[Code]...
if this silly but I am trying to declare a string variable by the following line
[Code]...
I have declared this variable in a module : Public GenericForm As System.Windows.Forms.Form
and then through code I can asign to that variable a specific form .For example GenericForm = Form1. Then I can use that variable to handle that specific form , for example :
GenericForm.Show
My problem begins when I want to handle a control on that form , for example :
GenericForm.TextBox1.Text = "aaa"
This code creates an error reading :TextBox1 is not a member of System.Windows.Forms.Form.I have been using code like this in VB6 and was quite useful ,but now in VB .NET I cannot .You see I have many forms on which there are some text boxes with the same name,so I declare a generic variable as Form and accordingly insert the code the desired text box conform the form I wish each time . Can I do this in VB .NET too ?
I have started using the builder class to create my connection strings for the sole purpose of making more generic connectivity code. However, I am stumped on this issue. The MS eConnect product apparently expects to receive integrated security=SSPI in its connection string if you want to use integrated security, (vs Integrated Secturity=True). I thought I would just pass "Trusted_Connection"="SSPI" to the builder class.
as it turns out, the item for Integrated Security is boolean and despite what the documentation says, will not give me SSPI in my connection string. Has anybody else found this issue and is there a simple fix for it? as for now, I'll simply strip out the item and replace it in my string.
I'm having a problem declaring a variable and setting it correctly.
BEGIN WORKING CODE:
private sub doSomething
Dim tokenHandle As New IntPtr(0)
Dim dupeTokenHandle As New IntPtr(0)
[Code].....
I am building a generic search form in my application. This will allow the user to search for various records throughout the application. The one thing I cannot seem to figure out is how to allow the declaration of the TableAdapter to change at run-time. Each part of the app will be passing a variable to the search form to specify which table should be loaded. In the form class I have the following:
FRIEND WITHEVENTS tbaSearchData AS database.databaseTableAdapters.TableOneTableAdapter This is great for TableOne. But, I have about a hundred tables that could be searched through. To load the data I'm using a DataGridView and populating it via a private method.
I have a class that I would like to link at construction to a given control (say a textbox)
I know I can put a variable into a subroutine referentially but is there a way to store it in the same capacity?
I've got
Option strict ON
Option explicit ON
How should I declare the variable:-
Dim bounds as? = (From item In xml...<bounds>
[Code]
These two snippets do the same thing - is there one that's better than the other, or is it just a matter of preference?
Using context As MyDatabaseDataContext = New MyDatabaseDataContext()
Dim test = context.Employees.Count
End Using
vs.
Dim context As MyDatabaseDataContext = New MyDatabaseDataContext()
Dim test = context.Employees.Count
After many many years of using Classic ASP, I am attempting to delve into the world of ASP.Net using VB. I have gotten way to use to being able to declare variables on a page, inlclude that file and use it everywhere. I am struggling to declare a global variable. I just need
[Code]...
what is the difference between declaring a variable in this way
ByVal
List As IEnumerable as
a parametre in a function
Dim
[Code]....
I come from C# (use VS 2005, .NET 2) and I know that when I declare a private variable I can "extract" from it the corresponding "property". In VB.NET I've declared a lot of properties (in the diagram class designer). Now am I forced manually adding the corresponding private fields?
View 4 RepliesGot a question regarding declaring a variable. Basically I have a module that writes to a text file using textwriter which is declared for the whole module to use at the top of the code. But what I want to do is clear the contents of the text file when the program is executed (using file.writealltext). The problem I have is that the file is obviously already in use as a result of the textwriter and the file cannot be modified because of this.
My question is: is there any way of declaring the textWriter object later on (not during the initial initialization of the module) without passing the object between functions? Setting the variable as inactive or something along those lines during initialization would be ideal.
I have 12 checkboxes jan, feb, ..... dec i want to display the checked checkboxes into a file i know how to write in the file but the format of displaying checkboxes is as follows if i checked jan, feb,march and april then output is jan,feb,march,april here my problem is how to collect checked value in array , and how to put comma betweem them.
View 7 Repliesinitialize an indefinite (eg. Decimal) array without setting boundaries on the array length?
View 2 RepliesWhat's best practice (in VB.Net):
Function GetSomething() as String
GetSomething = "Here's your string"
End Function
or
Function GetSomething() as String
Dim returnString as String = "Here's your string"
Return returnString
End Function
Obviously, neither of these implementations make any sense, but they're just meant to illustrate my point. Is there anything to be gained by using GetSomething itself to store the return value instead of declaring returnString locally and then returning that (does it avoid having an extra string allocated/instantiated - and if so, are there any performance/memory benefits)?
best way to sort an array of doubles into a lowest to highest array of the same length.
View 10 RepliesI have a problem involving late binding, and I absolutely cannot for the life of me figure out how to fix it. I have spent hours researching the problem to no avail, so I am turning to stackoverflow as a last resort.The problem is pretty much this: I am creating a grocery list application. I have a class named Item which stores the name, price, quantity, and description of an item on the grocery list. I have a module named ListCollection which defines a Collection of Item objects. I have created an Edit form which will automatically display the currently selected ListCollection item properties, but whenever I attempt to fill the text boxes, it tells me that Option Strict disallows late binding. I COULD take the easy route and disable Option Strict, but I'd prefer to figure out what the problem is so I know for future reference.I shall paste pertinent code here. (Late binding error is in EditItem.vb)
[code]...
I have tried declaring a String variable and assigning the Item property to that, and I have also tried grabbing the value directly from the List item (not using the Get function), and neither of these made a difference.
given the following Sub, how would I initialize byte array 'temp'to zeros and give it the length of the incoming byte array passed into the subroutine?
Sub ReceivePacket(ByVal buffer As Byte())
Dim temp() As Byte 'initialize to zeros and length of buffer
temp = buffer.Skip(17).ToArray()
End Sub
When declaring a byte array, what is the difference between the following? Is there one, or are these just two different ways of going about the same thing?
View 2 RepliesI'm trying to return an array of strings from a function, and got surprised by an error.
I would have expected this to work, but it produces an error:
Public Function TestError() As String()
Return {"foo", "bar"}
End Function
[Code]....
I guess I'm unclear on the meaning of the {}'s - is there a way to implicitly return a string array without explicitly creating & initializing it?
I'm working on a reporting section of code for an inventory app I'm making for my office.I call a text file, read every line into an array then populate information pages with what has been pulled from the text file.For reporting, I want to read every text file in the directory, reading each one into a multidimensional array.Thus I can call and report on each item, i.e.ItemArray(i,2) would be all systems with Windows 2008 EE..I have code that lists all files in the desired directory and counts each file, so I eventually get counts of how deep I need the first level of the jagged array to be. but not until after code execution. Basically how can I write each array of data to the jagged array.[code]But I get a null reference exception. "Use the new keyword to create an object instance".
View 8 Replies
