VS 2010 DatagridviewComboBoxColumn Dynamically Populating Items Collection?
Aug 10, 2011
I am trying to create a basic quoting tool but got stuck on how to clear and change the item collection from within a combobox for a datagrid.What we have is a list of 4 columns like a. Device b.TypeofService c.State d.Price Inside a sql database. Data is also structure like above as well.
I have a datagridview where the user will populate a,b,c and the price will be display and a total at the end. However a,b, and c aren't related in my current application. The combobox will show all possible dinstinct values for each column.
This works fine but I want to refine the application to only show the values of b. which are in the database after the user select the value for a. I have tried searching on how to do this as I assume to the Contry/State/City situation but could not find anything for a datagridview control in VB.NET.
Can anyone point me in the right direction? If I cannot do this dynamically from within a datagridview I was thinking of maybe creating three combo box outside and having it populating the datagridview afterwards but it wouldn't be as nice.
i have a datagridviewcomboboxcolumn that i am trying to populate. i set up the DataSource property using the wizard, there after i selected the DisplayMember from a corresponding drop down of fields from the table set up in the DataSource and then lastly i selected a field to be the ValueMember. problem is when i run my program datagridviewcomboboxcolumn is not populated.there is no drop down at all. what should i do to see my drop down or perhaps i need to set up in code.
Like i want it to read the lines i have in the text file but i get an error Each time i press the button Why?
Private Sub Button5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button5.Click Dim objreader As New System.IO.StreamReader("C:UsersJamesDesktopMusicas.txt") Do Until objreader.EndOfStream
Items collection cannot be modified when the DataSource property is set.
I have a DataGrid, with several columns. One of them is DataGridViewComboBoxColumn. I have a lot of items in this column - more than 1000 - and I need all of them. So grouping is not an option - all items must be there, users must be able to select from all.The problem is, DataGridViewComboBoxColumn becomes painfully slow, when number of items is about 1000, and above. This issues is well known to Microsoft, it dates back to Visual Studio 2005: [URL]...The problem is still present in Visual Studio 2010. Any ideas how to solve this?
Is it possible to fill DataGridViewComboBoxColumn with data partially? I mean (that was functionality fully working in Access), when you click DataGridViewComboBoxColumn, some items are displayed (lets say, 100 items). When you scroll down to the latest item, others are loaded (another 100) and so on. I don't see any other option to make DataGridViewComboBoxColumn working faster? Problem is, how to implement this? Has anyone meet that problem before?
I have a DataGrid, with several columns. One of them is DataGridViewComboBoxColumn. I have a lot of items in this column - more than 1000 - and I need all of them. So grouping is not an option - all items must be there, users must be able to select from all. The problem is, DataGridViewComboBoxColumn becomes painfully slow, when number of items is about 1000, and above. This issues is well known to Microsoft, it dates back to Visual Studio 2005:Is it possible to fill DataGridViewComboBoxColumn with data partially? I mean (that was functionality fully working in Access), when you click DataGridViewComboBoxColumn, some items are displayed (lets say, 100 items). When you scroll down to the latest
I am working on a weboage that will display questions and answers (maybe 5 at one time, maybe 7 at another time) returned from a database table. The questions will each be displayed in a div and the related answers displayed in another div. The question will have an icon "Show Answer / Hide Answer"
How can I go about creating a div and then populating it with values from a table?
Using a DataGridViewComboBoxColumn, the goal is to make the ComboBoxes accept user's new items and also the possibility of choosing items that are already present.I'm aware of using EditingControlShowing event of the DataGridView to change the DropDownStyle of the DataGridViewComboBoxEditingControl at run time to allow this, but I'm wondering if this can be done at a lower level.
What I'm doing now is extending DataGridViewComboBoxColumn, DataGridViewComboBoxCell and DataGridViewComboBoxEditingControl, hoping to change the EditingControl's DropDownStyle in the moment I instantiate it. So far, no luck.The debugger shows the right assignment is being executed, but nonetheless, the DropDownStyle is popping at the EditingControlShowing (using the event for debugging purposes) as DropBoxList, not DropBox, which is the intent.
Here follow the classes:
Public Class DataGridViewComboBoxColumnALT Inherits System.Windows.Forms.DataGridViewComboBoxColumn Public Sub New()
I am populating a collection from some tables in the database which serves as a look-up from controls (combobox) I am using but what I want is rather than hitting the database each time can I just cache the collection and get the collection from the cache? The look-up table may or may not change all the time so I would want to have a way to validate if the cached collection is still valid or not.
I have a ListBox1, a Button1 and a DataGridView1 How can I achieve, than everytime I push the Button1, the items from ListBox1 will also reveal in the DataGridViewComboBoxColumn's dropdown menu.... I'm using Visual Studio 2010.
currently in my application I have a Global Collection that is a Collection of Collections.Currently I am trying to add items/ elements to one of the child collections of the Global Collection but I am unable to use the collections methods of the child.When I assign a variable to the child collection and return the collection it is just an object with the collection inside.
Ex: Dim GlobalCollection as New Collection Dim ChildCollection1 as New Collection Dim tempCurrentCollection[code]......
I have a vb.net website with a gridview that currently has exam questions displaying vertically in each row like this:
Name question answer ----------------------- Joe question1 answer1 Joe question2 answer2
But I would like to change it, so that each question is a header, like this:
Name question1 question2 question3 ---------------------------------- Joe answer1 answer2 answer3 Jill answer1 answer2 answer3
This makes it more readable since each user is only listed once.I would like to stick with a gridview instead of rewriting all my code.I am actually binding my data to the gridview via some other programmers class. I am using LINQ like this:
I have a GRIDVIEW with columns, one of which contains a CSV of possible values for the dropdown that must appear on each row.
Private Sub GridViewParameters_RowDataBound(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.GridViewRowEventArgs) Handles GridViewParameters.RowDataBound If e.Row.RowType = DataControlRowType.DataRow Then[code].....
Depending on whether the type of control is a dropdown, textbox, or check box (feined in the table) it hides or shows the relevant control type. If it is a dropdown it needs to get its values from a CSV in a corresponding column. I have a SP that returns a these in table form if passed the id of the relevant row.How do I get that is from the gridview to pass to the drop down and load it correctly?
Before I get started let me tell you guys that I have googled and read the documentation from the codebank. Especially jmcilhinney's post. Here is my problem. I have a nicely working datagridview on my form.
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
I am having trouble with a comboboxcolumn in a datagridview. I have a MySQL table with "products" which i have managed to populate the combobox with, but i would like it so when a user picks a product from the combo list, the rest of the fields in that row are populated with the product information, price etc.
I have a DataGridViewComboBoxColumn in my DataGridView. I want to programatically drop down the list box so that the items arte displayed. With a normal combo box this is done with ComboBox1.DroppedDown = True. The problem is that the DataGridViewComboBoxColumn doesn't have the attribute DroppedDown.
I created a custom class for a custom object. I instantiate like so[code]...
Now, I have two problems. First, right now this is just overwriting the same object properties, again, and again. I need to somehow dynamically name the object. Then, I need to place these objects in an array so I can iterate through them...
I am using VB.NET (version 2008). I have two types of items populating in a listbox (checked listbox). For example: lets say one is type "A" and other is "Type B". Their names maybe same so if the user sees those items in listbox then he won;t be able to determine their type until he click on them and checks out its properties. I wanted that I add each item to listbox and colour them so that blue for example means type "A" is there and red means the other. So this way I will be able to know at a glance that how many item of what type is present. I guess it may not be possible to do that in a standard checkedlistbox. I am also using component factory's krypton controls which enhance the gui of an application. But I dunno if I can progress using that.
I'm trying to manipulate the events of the dataGridViewComboboxColumn in order to execute an SQL statement based on the value change of the cell (IndexChanged) and update the database table. Either this or how can i update several rows in a table from a datagridview ? if you check my previous posts you'll understand the whole story behind this question and to which grid i'm refering to.
I have a simple subroutine that loads a list from a database. I would like to be able to use the same code to load a ListBox and a ComboBox by defining the list type as the common abstract base class ListControl, and see no reason why I can't - except that VB.NET doesn't expose/implement/whatever the Items collection in ListControl. I note with frustration that this is not the case in ASP.NET. At moment my code is ugly because I have to check what type of list control I have passed in, in order to cast it to a type that has an Items collection. (My code may be ugly for numerous other reasons too, but it is beautiful to me). Is there a way to rewrite the code to avoid having to go through the testing and casting nonsense? (I've stripped it down somewhat so that all that remains is where the problem lies).
Sub loadList(ByVal db As SqlDatabase, ByVal strCommandText As String, lstHost As ListControl, Optional bClearList As Boolean = True, Optional bIsListBox As Boolean = True) If bClearList Then
I have a class that represents some business object, such as this:
Public Class MyObject Inherits SomeBaseObject ' Implements INotifyPropertyChanged and IDataErrorInfo Private mMyVariable as Integer Public Property MyVariable as Integer
SomeBaseObject implements both INotifyPropertyChanged and IDataErrorInfo, such that a Validate method will populate the appropriate IDataErrorInfo fields when setting the property values.I also have a collection that supports change events, which I eventually bind to a WPF DataGrid.
Public Class MyCollection Inherits ObservableCollection(Of MyObject) End Class
Part 1: Let's say that I have a business rule which says that no two items in my collection may have the same value for MyVariable. How do I set up my events (or implement additional interfaces somewhere) to perform this cross-item validation whenever the property value changes on any item in the collection?
Part 2: Suppose I have a list of integers such that whenever I add a new MyObject item to an instance of MyCollection or change the MyVariable property on any item already in the collection, the value of the MyVariable property must exist in this list of integers?
I often have a class defined and I also define another class that is simply a collection of the other class. To do this I found it easiest just to define the other class as Inherits List(Of Type). The reason I define a collection class is to add extra functionality to the collection. Take the following code for example.
Class Car Property Name As String Property Year As Short
how can I define my own collection so that I can reference it by index or name like that. Right now I can only reference it by index.
removal of items in a collection or list using the " For Each " statement to iterate through.This code works:
For Each item As ListViewItem In ListView1.SelectedItems ListView1.Items.Remove(item) Next
This code does not:
For Each itemChecked As Object In CheckedListBox1.CheckedItems CheckedListBox1.Items.Remove(itemChecked) Next
I have been reading on this for hours today to find out why the first code block works, but the second does not.What I've learned is the "For Each" statement implements the IEnumerable interface. I have seen these terms used many times and scratched my head when it didn't make scense, then just moved along, something to strain my brain about later.Today was later...So since the IEnumerable interface is used, the .GetEnumerator method of the IEnumerable interface is called upon at the beginning of the "For Each" block, this evaluates the collection or list as in: For Each item As ListViewItem In myCollection This is done at the beginning of the iteration through the myCollection, so if the myCollection is altered as in:
For Each itemChecked As Object In myCollection CheckedListBox1.Items.Remove(itemChecked) Next
The altering of the list returns the error:List that this enumerator is bound to has been modified. An enumerator can only be used if the list does not change.
I am trying to add the file information of the contents of a folder to a collection. Although I am getting the collection to hold the correct number of items that the folder contains, all of the collection's items are the details of the last file in the folder.
I'm trying to use a loop to go through each item contained in the folder and then adding the item details to a collection with the following line
nCounter += 1 collFileDetails.Add(NameOfItem, nCounter) Next NameOfItem
I've done a little bit of LINQ but I almost exclusively return some elements from a collection based on some criteria. Now I'm trying to do something similar; let's say I have 50 winForm Controls in a collection - I want to set the .Visible property = True based on the controls name.
How would I do that? Below is my failed attempt.
myControls.AsEnumerable.Select( Function (myControl as Control) ( myControl.Visible = (myControl.Name <> "Hidden")) )
I have a ComboBox control with some items added to the items collection in design mode. What I want is when an item is picked from the ComboBox a different value is actually used in the code, instead of what is displayed. I am aware of the DisplayMember & ValueMember properties, but I'm not sure if that is what I need to use. All the examples I found were for bound data.