I tried utilizing a collections Enumerator inside of a USING block to take care of the Enumerator.dispose call for me, however, I'm getting NullReferenceExceptions when trying to access the Enumerator.Current property after doing a MoveNext.
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For
Each
Item As
DataRowView In
lbOrdersNeedToBeVoided.Items
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I have these variables as shown below. The FadeMode is assigned on of the 3 integer values. I would like it to work like an enumerator, so that when I working with the code editor, IntelliSense offers a choice of the 3 possible values. Like x = Fademode.FadeOut
Const FadeIn As Integer = 0
Const FadeOut As Integer = 1
Const FadePause As Integer = 2
Friend FadeMode As Integer = FadeIn
If I am using an enumerator to parse a collection such as
Code:
''' <summary>
''' Checks to see if Node1 is a direct child of Node2
''' </summary>
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The object comparison of Enumerator.Current and Node1 passes an option strict check, but should I for readability and or for any other reason cast it to the correct type? I know their object references will ultimately be checked the same way, but is it generaly bad form to assume this?
Second question. I recently came across the use of the Enumerator v/s a For/Each loop through the collection, does anyone know the pros/cons of the use of either in specifi situations. Where one is favorible to the other or where they should or should not be used?
I am looking for a way to read an XML file at run time and construct an Enumerator from it. I got the reading and writing all working, it's just getting all the strings to create an enumerator that's the tricky part. I could get them into a collection of strings or maybe a dictionary, but not sure how to go about converting from these into an enumerator. The goal of this is to allow users to add and delete items from the underlying enumerators and eliminate writing hard coded enumerators. My idea is to allow users to extend the program without coding. This is a Winform vb app thats not using any database but just XML files to store and retrieve things.
View 7 RepliesIt looks like passing a list's enumerator to a function "byval" is quite different than passing it "byref". Essentially, regular "byval" passing will NOT change the caller's "enumerator.Current value", even if the function advances the enumerator. I was wondering if anyone knows why this is the case? Is an enumerator a primitive like an integer, without an object reference, and hence changes to it don't get reflected in the caller?This function is byval, and gets stuck in an infinite loop, spitting out "1" message boxes, because the enumerator's "current" never advances past 5.[code]The difference between the two functions is only whether the listFirstItem__ function accepts a byval or a byref enumerator.
View 2 RepliesAccording to the language specification guide for VB.NET Section 10.9.3. The enumerator expression in a for each loop is copied over into memory. If I have a list of 10000 objects that list will be in memory twice for the code below?
dim myList as new list(of bobs)
'put 10000 bobs in my list
for each x In myList
'do something
next
If I were generating the list from a linqQuery or some other such query it would make sense to generate that list at the for each loop statement thus not having the list in memory twice for example.
for each x in myList.where(function(x) x.name = Y)
'do something
next
If the LINQ query is unreadable on the for each loop, do I forgo readability and just put it on the for each loop declaration line? Should I declare the list in its own variable and just bite the bullet and have the list exist twice in memory?
if a call to For Each starts by calling the Enumerator's MoveNext, then Current, then MoveNext, then Current, and so on until MoveNext returns a False then it exits, am i right to say that the Reset is never called?initially i thought that Reset would be called when MoveNext returns False, i tried this (a msgbox would come if it was ever called but i got no msgbox at all)
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if that's the case, what exactly is the use of the reset in an ienumerator, and is it ok to leave it empty, as such
Is that possible to get current Enumerator (...or iterator? Don't know which tern is the correct one) in a LINQ query ? For example, I try to create a XML output (via LINQ to XML) of all currently loaded assemblies. [code] is it possible to somehow get current "index" (counter?) from LINQ's Selects? I would like to use it in XML. [code]
View 1 Repliesi have problem in vb.net window base application.i want to block TAB key from the keyboard.PI code or any useful hint to do that.
View 1 RepliesI assume i have more number of If and less End If i cant find it where its going wrong?
______this is the code below _________________________________
Private Sub CommandButton2_Click()
Dim app As Object
Dim Slide As Object
Dim ppApp As Object
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im doing a login i have finish it but you can close it by using alt+f4 so i need to block the alt key im using vb 2008
View 5 RepliesHow can i add this to Me.Controls within the With block. [code]
View 4 RepliesI am looking for a way to block registry changes unless I choose to allow them to be made. So basically if an application tries to make a change my program would display a dialog with information of the change and I can either click Allow Change or Disallow Change.
Only thing is I am not sure how I go about stopping a registry change before it happens.
it is possible to block the window key using vb.net...
View 1 Repliesin vb6 to block value in text box i using :
text1.setfocus
sendkeys "+{home}"
How if i use in vbnet 2005 ?
I'm working with an antivirus scanner.But I would like my scanner can block websites.So that some URLs are blocked from any browser[code]...
View 6 RepliesI have this block of php that i want to convert to c# or vbnet. I am stuck on the array methods since there is no direct equal to the is array and other bits like array merge. I know that arrays behave differently in php than in c# but thats about it. I am looking online but have not found anything yet.
private static function processArgs( $arguments )
{
$args = array();
foreach ( $arguments as $arg ) {
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I am coding in VB.NET.
Currently, I am enclosing object initialization and usage in a Try/Catch block and then tear it down (dispose, close, set to nothing) in the Finally block. The problem is, a C# 'using' block is so easy to use and would clean things up in my code.
Is there a VB.NET equivalent? Or is my Finally block tear-down solution the only way?
i have a simple question. in vb6 you can block the form using modal. but in vb.net i dont find any thing like this. so is there a way to block a form when other is opened. now i do this:
Dim frmDisc As New frmDiscount
frmDisc.GET_SENDER(Me)
frmDisc.Show(Me)
and in form Discount i do this:
Public Sub GET_SENDER(ByRef frm As Form)
frmSender = frm
End Sub
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How to block popups
View 1 RepliesHow to block shutdown using vb.net?
View 1 RepliesI have a form in vb.net that has a ShockwaveFlash object in it, and I get an IE popup requesting to download a file. I changed variables in it and it blocked some of them.
View 5 RepliesStudying Ruby and the Do block. Coming from much c# I didn't see much that reminded me of Do, but then VB came to mind with the With statement and one which I wish was in c# (maybe it is and I never saw it?). The two statements, Do and With, appear similar.Is the With statement in VB the same as a Do block in Ruby? [code]I understand what I will get just from looking at it. I know that I will get a new record in my database with the above information, but I do not know why. Why did book become TheBook.new?
View 5 RepliesFor the code shown below, how would I use a try/catch block to handle an error if it were to occur?
TOTKILO.Text = KILO.Text * TOUCH.Text * 0.01
TextBox10.Text = TextBox9.Text * TextBox8.Text * 0.01
K = Math.Round(Val(TOTKILO.Text) - Val(TextBox10.Text), 5)
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I used VB.Net controls and LINQ to SQL to perform all Updates and Inserts, so when an error occurs I want to show "Enter Data Correctly", how do I do that once I catch an exception?
I often use the Try block to catch exeptions, and I have read in the help pages to do with the Finally statement. But, from what I understand it has no use whatsoever. Why would I use Finally instead of just ending the Try block. For example, from what I know
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I have a Web Browser that navigates to some websites, and I would like to know how would I go about blocking ads, just wondering is there any examples around, or can someone give me some ideas.
View 4 RepliesI have a very simple VB 2005 program which runs on our W2K and XP systems, but when I try to run it on W7, the UAC throws up an admin login block. I have tried signing the assembly, to no avail. The entire program is below:
frmSimpleTest.vb:
Public Class frmSimpleTest
Private cabsdirectory As String = "C:HOTRMHMR"
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We have a current implementation of a log file manager where it's two main purposes are to 1. rename files generated by other programs with a date/time stamp so they create new ones, and 2. delete files older then X amount of days from a specified folder. The program also makes it's own log file which records when these events happen.Do you think the Logging Application Block would be useful in this instance? The old file manager is written in VB 6.0 and an upgrade to VB .Net would not take too long, but is it worth it to try and implement LAP into it?
View 1 RepliesI have a simple function which tries to get a value from an Obout grid filter column, and if the value is empty, ignores it and moves on. For some reason this code ignore my catch block and always shows a System.FormatException when the input string is empty More bizarre, if I use visual studio's debugger and set a breakpoint on that line, the catch block functions normally (after I continue from that line). I have already confirmed that my Debug | Exceptions | CLR are not set to catch when thrown. I have also confirmed this same behavior in the production version.
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