Forms :: DataGridView DataError Exception When Removing Items From Bound List?
Nov 2, 2011
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.
View 1 Replies
ADVERTISEMENT
Oct 17, 2011
Imports System.Collections.Generic
Imports System.Net
Imports System.IO
[Code]...
View 3 Replies
May 24, 2011
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].....
View 2 Replies
Oct 22, 2011
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.
View 1 Replies
Jun 8, 2011
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
View 5 Replies
Jan 31, 2010
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 Replies
Dec 17, 2009
I 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 Replies
May 2, 2010
If 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?
View 2 Replies
Dec 14, 2010
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.
View 15 Replies
Mar 7, 2012
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?
View 2 Replies
Oct 1, 2010
On my form I have 3 textboxes. They get their data from a database query. The trick is the database may return 1 result or up to 3. If the query returns only 1 result, I want the first textbox populated, 2 results, 1st and 2nd textbox populated, etc... I also want to be able to track CurrentItemChanged Event for updating purposes. My initial thought was to use a list object as the binding source but how would I cycle through the list if it returns more than one so that I can assign the values to the 2nd and 3rd textboxes or if data is entered in to a blank textbox I want the currentitemchanged
View 6 Replies
Sep 29, 2010
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.
View 2 Replies
Jun 12, 2010
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]...
View 3 Replies
Mar 10, 2009
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 Replies
Sep 23, 2009
I'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]....
View 2 Replies
May 13, 2009
I have been reading up on this, but I can't get it to work for me. I am reading in comma delimited text into a three-column datagridview control. The third column is a combo box which only accepts certian values. If the data being imported into col 3 is not in the combo box list I get an error that tells me to handle the data error event.trying to capture that error and get rid of the default error message box. I am working with a Try/Catch statement, but it doesn't seem do anything.
Do Until fileReader.EndOfStream
stringLine = fileReader.ReadLine()
If Not stringLine.StartsWith("'") And Trim(stringLine) <> "" Then
[code].....
View 3 Replies
May 18, 2009
I cannot Unresolve a post.I have a datagridview control with a combo box. The user loads data from a file into the control. If there are errors (the element in the combo box column is not in the combo box list) I would like to:
1. capture the row in which the error occurred, and store it in code/memory
2. change the cell backround to red (this is not that important)
3. continue without a message at the time of the error
4. post a message with all of the errors after the load is complete
I am using the code staight out of the Microsoft example to try to figure how to do this, but it is not posting any messages when I load bad data, so I am not getting any smarter from the example.[code]
View 2 Replies
Dec 8, 2011
I have a datagridview binded to a list of objects... I have a column named Selected containing a checkbox. When these checkboxes are checked and a button is clicked, I want those particular rows to be removed. I initially set it out to iterate through the grid's rows and RemoveAt(SelectedRowIndex) but of course when it removes an object from the List of objects at the selected row (IE Row 1, 4 and 6), the list indexes change and it fails to work properly when it goes to remove the next row since Row 4 is now row 3 in the list...? What is the best way to do this?
View 4 Replies
Nov 28, 2009
I'm trying to clear a DataTable and repopulate it, and the DataTable is bound to a DataGridView. Here's the code I'm executing:
vb.net
Using reader As MySqlDataReader = myCommand.ExecuteReader
SyncLock tableLock
running.Clear()
[Code]...
If you want to replace this standard messagebox, handle the DataError-expection
When debugging, there is no break in the code. The messagebox just pops up without showing me exaclty where the error is located.
View 4 Replies
Oct 13, 2011
I'd like to have an updateable DataGridView that's bound to a database-driven business object. It needs to handle all aspects of CRUD and be sortable and filterable as well.
Most of them simply bind to an object (non-database, manually filled) and do not allow you to Add, Delete, and Edit records. Furthermore, they basically never show how you would perform sorting and filtering.
I think the biggest things I'm not understanding are:
1) How do you make the DataGridView perform additions, deletions, and edits on an object.
2) How do you program your object to handle additions, deletions, and edits. Do you just need methods that use ADO.Net, NHibernate, or Linq to SQL (or any other CRUD handling mechanism)?
3) How to make this filterable and sortable.
Is this overly difficult to do or why am I have so much trouble finding examples for this?
View 2 Replies
Feb 6, 2012
how the various elements that help you handle errors work together. Have tried several options and can't make head nor tail of it. The underlying table has two columns, an autoincrement integer and a text column with the following settings:
[Code]...
View 6 Replies
May 22, 2011
how do i get items in combo box to appear in a list box
View 1 Replies
May 28, 2009
how 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]....
View 2 Replies
Jun 4, 2010
I have a DataGridView that is bound to a DataSet I created from a database table named Contacts. The Contacts table contains a field called StatusId. StatusId is a foreign key to a table called Status. The Status table contains StatusId and StatusName.
[Code]...
View 1 Replies
Apr 29, 2011
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.
View 3 Replies
Dec 6, 2011
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 Replies
Sep 17, 2011
I have an application written in vb where I keep getting 'index out of bound' exception.I want to catch the exception only when its 'index out of bound' exception for other I have generic message. I am able to generate the generic message but cant. I am using the below code but it doesn't work .
If (ex.Message Is "Index was outside the bounds of the array.") Then
Dim sMsg
As
String =
"Function <Sample Function>.Too Many inputs" & ex.Message & vbNewLine & ex.StackTrace
[Code] ......
View 5 Replies
Aug 18, 2010
Hi, 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]...
View 4 Replies
Feb 6, 2009
I am relatively new to C# and winforms, although I have been using Java for years, so forgive me if im asking something relatively straightforward!I have a DataGridView, it needs to update regularly so I wish to provide a Collection of objects as its DataSource and NOT a database table.So far I have a List<MyObject> which will be constantly updated via a BackgroundWorker thread. I want my DataGridView to update when a change has been made to the List i.e. if the objects are resorted, added to or deleted from etc.Currently my DataGridView only displays the first object I add to the List, if I add more the DataGridView doesn't update to display the new objects added.This is a basic overview of how im coding it:
private List<MyObject> myList= new List<MyObject>();
myDataGridView.DataSource = myList;
Then my BackgroundWorker thread updates the list, e.g.
[code].....
View 4 Replies
Nov 1, 2011
What I am trying to do is to instantly apply a filter to a large list of data such that the list is updated almost immediately regardless of the number of items in the list. I have this working using a listview right now but it is far from instant, a list of 5000 items takes over a minute to get through. What I do currently is to maintain a cache of my data that my listview entries are based on. When the user selects a filter I parse this data one item at a time and determine if each item should still be displayed in the listview, if not I remove it. The complexity of determining whether or not a data entry meets the filter requirements is O(1), but just getting through each element in a loop takes significant time, and so does updating the list view graphically at the end of the process.
I have considered using a datagridview instead, using a database connection. I have never done this before and my main question here is whether this would allow me to do what I have described. With the database I could form an SQL query to return only the items that meet the new filter requirements... but would the data in the form update immediately, or would there still be significant delay?
View 3 Replies
