Forms :: Error In Removing Items From The List Box?
Oct 17, 2011Imports System.Collections.Generic
Imports System.Net
Imports System.IO
[Code]...
Imports System.Collections.Generic
Imports System.Net
Imports System.IO
[Code]...
have a binding list which i want to be able to add and remove items.This is the class im using
Friend Class ExecutableItem
Public Property Text() As String
Public Property Method() As Action
[code].....
I am using a DataGridView bound to a BindingSource which is itself bound to a List of objects. This all works well until I remove objects from the list. If I am scrolled down to the bottom of the DataGridView and then remove a bunch of items from the list it is bound to it generates a DataError exception because the length changed and the rows I am looking at no longer exist... I changed my code to handle that error, but now instead of popping up a message it SLOWLY erases the data in each of the newly invalid rows at the end of the table (I think each time it does one it generates a new DataError, which is why it is so slow).
How do I prevent this? I want to be able to dynamically (and programmatically) add and remove items from the table without the possibility of this error... I assumed this would be handled automatically as part of the data binding process but I guess not.
Imports System.Collections.GenericI
mports System.Net
Imports System.IO
Public Class Form2
'Dim filename As String
Public ftpSettings As FtpClient
[Code]...
I don't know what's wrong, i can only move the 1st item but the second and so on doesn't make any changes. It remains in a listbox.
I have button that adds items to a list box and a button that removes it...the one that adds it works great but when i select an item to remove it doesn't remove it..i don't know if there's something wrong with the code or not..
Private Sub btn_Remove_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_Remove.Click
list_MyOrder.Items.RemoveAt(list_MyOrder.SelectedIndex)
prices(list_MyOrder.SelectedIndex) = 0
MsgBox("Select any item to remove")
End Sub
I have a form with 2 listview's and I want to remove that items in the listview1 that area duplicated on the listview2.
View 8 RepliesI have a generic list that I'm removing items out of using List.Remove(Object). I have been removing items but whenever I get to the fifth item I'm removing it fails and does not remove it from the list. It doesn't seem to matter what I'm removing but everytime I try to remove five items it fails on the fifth item.
View 4 RepliesIf I have 3 times selected and when I click "submit" for example I want all my selected items to be removed, but when I try to do this only my first selected item is removed.
ListBox.Items.Remove(ListBox.SelectedItems)
How do I remove all 3 items from the list box at the same time?
Public Structure ReportOrderType
Public ReportName As String
Public ReportDate As Date
Public SaveFile As String
End Structure
[Code] ....
Basically, I have a list of reports. In one place they get ordered, and later on the program looks to see which ones have come back -- see if the .SaveFile exists on disk. If it exists, then that report gets processed, and then I want to remove that item from the list of reports-on-order. However, I get an error message back that by doing the .Remove(R), I've changed the list itself & things won't go well with the rest of the For Each loop, which makes some sense.
When I get to this routine, the list of ordered reports will be something from a couple of dozen or less, and some number of them (perhaps zero, perhaps all, probably a few) will exist & be processed & then should be removed from the list. How should I go about accomplishing this? This is my first time working with List(of t) as a Visual Basic tool; everything I've used in the past has been with arrays, and I can do this there.
I have the following
Public itemArray As New List(Of ItemArrayStructure)
Public Structure ItemArrayStructure
Dim DisplayText As String
Dim Checked As Boolean
End Structure
If I know the DisplayText of an item in this array, how can I remove it?
I have a small requirement and that is as follows:
I am populating a ListBox using stored procedures and the ListBox is populated as follows:
lstItems.DisplayMember = "emp_name"
lstItems.ValueMember = "login_id"
lstItems.DataSource = accessFunction.getEmployees
The ListBox gets populated correctly. After it is populated, i have a CommandButton and on the click event of the button, i want to remove selected items from the ListBox. So in the click event of the CommandButton, i have written the following code:
lstItems.Items.Remove(lstItems.SelectedItem)
After selecting an item from the ListBox and when i click the CommandButton, i get an error as "Items collection cannot be modified when the DataSource property is set".
how i can delete items from the ListBox.
I've searched on the Internet and I can't find a solution to this simple problem. I've also looked on Microsoft's MUCH improved MSDN site and haven't found a solution, so here it goes. I'm trying to remove an entry from a list of class and it doesn't get removed. Here's a sample of the code I'm trying: (I renamed the class and variable names to make it a simple example)
Dim lstClass As New List(Of TheClass)
Dim mClass As TheClass
I tried this first
mClass.filename = "The Entry to Delete"
lstClass.Remove(mClass)
[Code]...
I am trying to learn how to work with the different controls in Visual Studio for VB.Net in particular the List View and Tree Views. I don't have any code to show as I am not working on anything in particular just messing around with it to learn what the different controls do that weren't covered in my Intro to VB.Net class last semester.I would like a clearer explanation on how to actually use code for these controls. In particular adding and removing items from the List and Tree Views using code.
View 1 RepliesI've gotten a listbox control to populate with a list of installed fonts, but I need to be able to click a button and remove the selected item from the listbox. How do I do this? Every time I try, an exception is thrown.
Here is the code:
Public Class Form1
Dim fonts as New Drawing.Text.InstalledFontCollection
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
[code]....
For Each s As String In list
If s.Contains("Hello") Then
list.Remove(s) 'ERROR Collection was modified; enumeration operation may not execute.
End If
Next
Why do i get that error?
how do i get items in combo box to appear in a list box
View 1 Replieshow to set the value of the text that is displayed for each item of a list control, such as a checkbox list, but really this applies to most list controls, not just the checklistbox control.
I have a checklistbox control,
Friend WithEvents clstTasks As System.Windows.Forms.CheckedListBox
that I usually want to populate with a list of task names. I call the add method to add a Task object to the list. I know that if I override the ToString method, whatever value is returned by that function will be displayed as the text for the list item.
However, in rare situations, I want to display something else other than just the name. For example, perhaps I want to display the name and the value of another property, such as the value of the Boolean property "Optional" shown in parenthesis following the name.
The best that I can think of is to define a property which is set in the GUI layer and then used by the ToString function to determine how it should behave when called. If the controlling property is set to one value, the ToString will return the Name, else it will return the Name followed by the value of the Optional flag. This seems a little disjoint a kludged to me.
The other alternative which seems a little overkill is to define a new class which inherits from Task, for example TaskOptional, which overrides the Tostring method on the base class. In this subclass, the ToString function would return the Name/Optional flag value. However, this, too, seems a little nuts to have to come up with a new class just to modify how the text is being displayed in the presentation layer. I feel that I should be able to control this in the presentation layer without changing the business object or creating a new derived object.
What is the best way to accomplish this?
For Each CurrentTask As Task In _MasterTaskList
clstTasks.Items.Add(CurrentTask, True)
Next
[Code]....
I've got a Checked List Box full of PC names that the user can check. I've also got a Combo Box that lists the location of the PCs - if the user chooses one of the locations in the Combo Box, it automatically selects all of the PCs in the Checked List Box that are at that location.
However, if that group of PCs are way down the list in the Checked List Box, you can't immediately see that they were checked.I'd like to know if there was a way to have the application automatically scroll/jump down to the area of the Checked List Box containing the PC's that were just checked.
how to write a program for a list box having 10 items in that just by a single click on one of the item it should be written on the button if a list is containing notepad than by clicking on the button it should open the notepad?
View 2 RepliesHi, I'm working on a program that reads text entered into a textbox and creates a list of items by separating entries by commas. Everything is working fine, except, because I am using an array to store the items in the list, I have a limited number of entries. This is only a problem because, as it is written currently, each comma counts as an individual entry. Therefore, users can enter ",,," for example, and it would use up 3 places in the array.
I'm looking for a way to check to make sure there is text after the comma before adding an entry. I've attempted to use the .substring command to check the character after, which works until it gets to the last character. Because there is no character after that, it will give an error.
Here is my code for extra clarity:
Public Class frmMain
Dim intCounter As Integer 'Stores the # of commas in the string
Dim Messages(49) As MessageProperties
[code]...
I am trying to search through listview in VB.net 2008. It works fine with small list, but when the list is big ( around 25000 rows), if I search multiple items , it fails saying that index is not valid. Obviously what I understand is , it it tryiong to remove an index does not exist. But I am unable to figure out where exactly it is going wrong.
PS : while it is doing search through the entire listview, I am incrementing index = index+5 becasue I want the next 5 rows to be in the selection state as well.This is the code Private Sub TextBox1_KeyUp(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles TextBox1.KeyUp If (e.KeyCode = Keys.PageDown) Then
[Code]...
I am populating a combobox with data from a .txt file; however, there are 1000 entries but only 4 different possibilites 1, 2, 3, and 4. How can I have the combobox only allow a selection of the 1-4 with repeating all 1000 numbers?
View 3 RepliesSo I have three listboxes, LB1 is an uploaded list, LB2 is a master list, and LB3 is generated from LB1 items that are NOT in LB2. I have a button that replaces the selected item from LB1 with the selected item from LB2, woot.Since LB3 is a subset of LB1, I want to be able to select the items from LB2 and LB3 and have it replace the item from LB1 but running into some trouble with finding the appropriate item without selecting it. [code]
highlight Fred from LB1 and Freddy from LB2, click and Fred becomes Freddy in LB1. I want this same change to happen but by selecting the "Fred" located in LB3 (If LB1 is hundreds of names long, I don't want to have to sift through it and only make the changes that need to be made). [code]
Im working on a school project where i add items to a listbox in two columns. The first being the name of a course and the second being the credit hours of the course. I can add and remove the items just fine BUT when i remove an item im also required to subtract the credit hours of said item from a variable i have called "totalhours." Essentially im trying to figure out how to subtract a certain piece of a selected listbox item from my class level variable.
View 2 RepliesI got this code but it won't work...
For Each item In ListBox1.Items
For i As Integer = 0 To ListView1.Items.Count - 1
If item.ToString = ListView1.Items(i).Text And ListView1.Items(i).SubItems(1).Text = TextBox4.Text Then
[code]....
It only deletes 1 listbox item while there are more items that have to be deleted.after debugging i get this:List that this enumerator is bound to has been modified. An enumerator can only be used if the list does not change.
I want to remove items from a listbox 1 at a time. I have two timers set up to remove the two types of items that are put into the list box. When there is a "Player 1 killed Button 1" following a "Player 1 killed Button 2" or vise-versa they get removed at the same time. Is there any way to prevent this?
Code:
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
Dim XP As Integer
[Code] .....
I need to know if there is a way to remove any items from a listbox if they contain no text. Like if there are three items(Blah, ,Blah) listed in the listbox like so (remove the middle line that is empty so the listbox now contains two items(Blah, Blah) listed like so Or if there is a way to do this to a textbox that would work too. I'm working in VB 2010
View 3 RepliesSo, I am working on something which requires various session Data to be held. I need to be able to delete certain data from the session, but not clear the whole thing. Obviously, I can manually delete session items with
[Code]...
I'm wondering what the proper way to remove an item from an array is. The way i am doing it at the moment is:MyArray(0) = NothingIs this the best way to do it as i'm having problems with my programme and i think it may be something to do with this
View 10 Repliesi'm creating a web form and i want a user to be able to make certain selections and then add the selections to a text box or listbox.Basically i want them to be able to type someone name in a text box ... check some check boxes and for it up date either a text for or a list box with the result on button click...
e.g.
John Smith Check1 Check3 Check5