How to bind data from database to combobox of winform in VB.NET .
Database : MSSQL server managemant studio
Front End : Vb.net 2008
In the combo box binding,i need to put "Product_gid" in index and "Product_Name" in the value of combo box.How do i add an item "Select" in the 0'th position of Combo box,So that every time i opened the list of combo box,the 1st item will be "Select",other from database.
I have the following structure
|-Table 1
|--PK IDT1
|--Name field
|-Table 2
|--PK ID
|--FK IDT1
|--Name field
I want to bind Table 1 to combobox1 and Table 2 to combobox2 so as when someone selects a value in combobox1, combobox2 populates with only the rows with the FK IDT1 value from combobox1. Is this possible with databinding or do I have to code it?
I'm trying to bind CheckedListbox's Cheched items to Combobox my code is given below
Private Sub chklColumns_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles chklColumns.SelectedIndexChanged
cmbSort.DataSource = chklColumns.CheckedItems
End Sub
whenever I check an item first time it loads one item to the Combobox, but when I select second item still I have single item in the Combo...
Short and simple question. In Winforms you can bind a dataview to a combobox or some other control by simply:
combobox.DataSource = dataview
combobox.DisplayMember = "Something"
In WPF I've generally done databinding using an ObservableCollection and edits to the xaml. Is there a way to quickly do it, like the above? Edit: This seems to be the simplest/quickest thing I can come up with, anything inherently wrong with it?
[Code]....
If I turn off automatic updating of a binding data source by setting DataSourceUpdateMode = Never and then use a button to update the whole lot (using binding.WriteValue), a problem occurs - Namely, only the first bound control's data source is updated. All other controls are reset back to the original values.This is because when the current object changes (as happens after the above WriteValue), if ControlUpdateMode = OnPropertyChange, then all the other controls re-read in the value from the data source.
One way is to derive a class from BindingSource and add a WriteAllValues method.This method does the following:
(1) For each Binding, save the ControlUpdateMode
(2) For each Binding, set ControlUpdateMode = Never
(3) For each Binding, call the WriteValue Method
(4) For each Binding, reset ControlUpdateMode to the saved value
(5) For each Binding, if ControlUpdateMode = OnPropertyChange, call the ReadValue method.
If working with your own classes, would implementing IEditableObject resolve the issue?In another control I'm working on, I implement my own binding. The way I get around the issue in that is with the following code. (I've put in the bare minimum, I hope you can follow it!):
Private Shared ControlDoingExplicitUpdate As MyCustomControl = Nothing
Private Sub UpdateDataSourceFromControl(ByVal item As Object, ByVal propertyName As String, ByVal value As Object)
Dim p As PropertyDescriptor = Me.props(propertyName)
[code]....
So, when UpdateDataSourceFromControl is called, all the CurrentItemChanged events will be called for all other controls in the same BindingSource. However, because ControlDoingExplicitUpdate is set, they will not re-read in the value from the data source unless they happen to be the control that did the updating.ControlDoingExplicitUpdate is set to Nothing after all these events have completed, so that normal service resumes.
In a winforms application (VB, VS2008 SP1) i bound a checkbox field to a SQL Server 2005 BIT field. The databinding itself seems to work, there is this litte problem: user creates a new record and checks the checkbox, then the user decides to create a new record (without having saved the previous, so there are 2 new records to be submitted) and checks also the second.
[Code]...
I have a custom control with a bindable property:-
Private _Value As Object
<Bindable(True), ... > _
Public Property Value() As Object
Get
[code]....
Also, here, I'm adding a handler to the DataBindings.CollectionChanged event.This is the second place that I retrieve the type:-
Private Sub DataBindings_CollectionChanged(ByVal sender As Object, ByVal e As System.ComponentModel.CollectionChangeEventArgs)
If e.Action = CollectionChangeAction.Add Then
Dim b As Binding = DirectCast(e.Element, Binding)
[code]....
I need the first place, because the BindingContextChanged event is not fired until some time after InitializeComponent.The second place is needed if the binding field is programatically changed.Am I handling the correct events here, or is there a cleaner way to do it?
Note: My GetValueType method uses the CurrencyManager.GetItemProperties....etc, to retrieve the type.
You have a pseudo-table class and a pseudo-row class. The row is somewhat generic and has no strongly-typed fields. It follows the typical dictionary interface
Dim age As Object = person("Age") 'accessed via default property Item
vs
Dim age As Integer = person.Age 'an actual property typed as an Integer
What's the pattern to use so that we can bind our pseudo table and its rows to a grid or combo box?
Dim rs As New clsResultSet(tblPeople)
Dim id As Object = rs(0)("Id") '913
Dim name As Object = rs(0)("Name") 'Ted[code].....
I'm trying to add some extra key/value pairs to a combo box using VB.NET. The initial item list is generated from a hashtable, which contains a collection of objects.I've managed to add the extra values to the box using the Add method, however I now run into problems when reading back the selected item from the combo box because some list items are objects, while others are strings.
My best option seems to be to load the initial data as key/value pairs by looping through the hashtable, however this doesn't seem to be working too well either because I'm still getting errors.I'm getting frustrated because it's taking me hours to do something that should take 5 minutes!
i wanted to link options selected from Comb box A (general) to specific options in combo box B (specific). I want to pick a word in Combo box A that has specific words/phrases in Combo Box B show. But not all the words to show in the combo box B if they aren't associated with the Word picked in Combo Box A. Ex.When "Soda" is picked in A, only "Coke, Sprite, Fanta" should be visible in combo box b, not everything else.This is the code i used to make the boxes, but i don't know how to link them.
Private Sub MainForm_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
' fills the combo boxes with values
Me.xGeneralComboBox.Items.Add("Soda")
Me.xGeneralComboBox.Items.Add("Juice")
[code]....
How to use a databound combo box to display one field in the drop down, and another as the combo box text on roll up? Using VS 2005... For example, I have a datatable that has 2 fields. One called "ShortDesc" and one called "LongDesc". I want to be able to see the "LongDesc" column values in the drop down on the combo box. When I make a selection, I want the text in the combo box to read the corresponding "ShortDesc" value.
[Code]...
I am getting an error when i try to populate some combo boxes with a value, the combo box has values in and the right amount the code is getting the right number.
the error msg is "Object reference not set to an instance of an object."
Combo box 2 is filled based on a selection made in combo box 1 and a listview is populated based on the selection made in combo box 2.When the LostFocus event completes in combo box 1, it hits the LostFocus event in Combo Box 2 but it shouldn't. How do I prevent this from happening or if I can't prevent it, how do I work around it? The following is the code used.
Private Sub cboCategory_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles cboCategory.LostFocus
[code].....
I've got some code like the following. I want it so that when I chose an item in 'select 1' it changes the in the second combo box but I'm not sure of the best way to go about it. Does it have to be AJax or can it be done with just Javascript?
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
[code].....
Is it possible to set a project default for VB.NET winforms projects so that the default Modifier for controls added to winforms is Private (not Friend)?I know there's a "modifiers" property in the properties window so I can set it for each individual control however I would like to change the project so from now on myself and other developers have to specifically decide to change from friend to private. (Which I would strongly discourage them from doing).I believe there is no way of doing this, but on another forum a while ago someone mentioned it would be possible with an add-in (but didn't name the add-in or where to get it).
View 1 Repliesis there a way to set a single cell as a combo box? it looks to me that you can only set the whole column.
View 5 Replieshow do i program by saying if a certain item is selected in a combo box then that item will not appear in a second combo box. i have this code for now but it does not work
[Code]...
I know how to add the items during design time but how do you add the items through code. I want to fill the combo box in the datagrid with the results of an SQL query?
View 3 RepliesI have a form with 8 combo boxes and would like to disble certain combo boxes, depending on what was selected in another combo box. The reason is so the user will not have a blank return on a query. The first form I created like this worked great, no issues. This form only allows one combo box (Number_of_Lightheads) to disable any others. Below is the code I have for this Form. why the other combo boxes will not disable the ones that are called out in the code?
Option Compare Database
Private Sub High_Def_AfterUpdate()
If Me.High_Def = Yes Then
[Code]....
how do i program by saying if a certain item is selected in a combo box then that item will not appear in a second combo box i have this code for now but it does not work
j = 0
Do While j < cmbSession.Items.Count
If (j <> lesson) Then
[code].....
I have a list of strings. How do I bind it to a listbox so that the listbox updates as the data of the list changes? I'm using vb.net.I've tried this so far. I've manage to display the data, but not change it:
Public Class Form1
Private mycountries As New List(Of String)
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[code]....
I've also tried this:
ListBox1.DataBindings.Add("items", mycountries, "Item")
But items is readonly, so it doesn't work.Also, if I want to bind the enabled property of a button to a boolean, how can I do that?I've tried this but I don't know what to add for the last parameter.
Dim b As Boolean = True
Button3.DataBindings.Add("Enabled", b, "")
I have an ASP.NET page with a Wizard control containing several steps and about 80 form fields. The data is collected and inserted to a database from the code behind page. I need to set this form up so you can not only insert, but edit a record as well. So I want to databind the fields. I'd rather not use a FormView because then I would have to revise my existing code, since you can't access controls inside a FormView directly. Is there a way to databind the fields without using a FormView?
View 1 RepliesI have a button that i basically want to either show or hide it based on if a certain string has a value or not. I create the buttons in code so i was trying to used databindings with a converter but i can't seem to get the converter on the binding after the value changes. I'm not sure if I'm going after this correctly or not... Here is what i have for creating the button and the binding and the converter. "sFileLocation" is a string inside my class "QuestionsFile". This works for initialization but its just when the value of the string changes, this binding doesn't see the change and doesn't run the converter and all that for me...
Dim btn2 As New Button
Dim b2 As New Binding("sFileLocation")
b2.Mode = BindingMode.TwoWay
[code]....
The thing I don't understand too is that the binding works fine if i just binding the property to the Button.Content. So the property is updating correctly when it gets changed, and the buttons content changes accordingly.
I'm trying to do something with databinding between 2 controls...Here is a sample code (that doesnt work - and that is my wonder):
Public Class Form1
Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
'Me.TextboxPlus2.DataBindings.Add("Text", Me.TextboxPlus1, "Text")
[code]...
Is there a way to fill a checked list box with data from a sql table and then use the checked items as parameters or a stored procedure?
View 5 RepliesI have an ASP.NET page with a Wizard control containing several steps and about 80 form fields. The data is collected and inserted to a database from the code behind page. I need to set this form up so you can not only insert, but edit a record as well. So I want to databind the fields. I'd rather not use a FormView because then I would have to revise my existing code, since you can't access controls inside a FormView directly. Is there a way to databind the fields without using a FormView? I'm new at this by the way so sorry if the answer should be obvi
View 3 RepliesI want to databind my catagory table to a dropdown list but thecategories aren't going to be in order like:
categoryID Name---------------------1-----------apple2-----------wiper blades3-----------band aids4-----------pear5-----------raisons6-----------tiresHow would I be able to make the list look like:
[code].....
how to add sql statement in my code..here's my code for the form load..[code] want those textboxes to displayed only data for a particular person something like "Select * from Staffapplication where MID ='" & frmLeave.txtUser.Text & "'")how to add the sql statement in my code??
View 10 RepliesI would like to databind to a property that requires arguments.
I thought about defining custom columns and cells because the parameters that the property requires are available from the within the object bound to the row, but I'm having trouble materialising this idea.
As an additional problem, that I think leads on from this, I have also created a custom column and cell for the datagridview that takes the implementation of an interface during it's construction. I have added this column to the datagrid view programmatically (passing the Interface implementation to the column constructor). I've overridden the paint method which evaluates a property from the Interface implantation using arguments from the other rows in the column, but it doesn't seem to call the paint method at all. Even on DataGridView.Refresh(). Essentially I would like this column to also update, evaluate a property from the interface implentation using arguments from the underlying object bound to the row and print this number in the cell.
The reason for this second problem is so that I can implement the interface many different times and just at a column dynamically to display it's evaluation.
Is it better to perform data access operations on the page and then populate the properties of each usercontrol with the retrieved data. Is it better if each UC calls the business layer and pulls its own data independently without having to depend on the page.Existing Conditions:
1. Any information (Querystring, URL, etc) that the page would use for data access is also available to the individual UC's
2. Both solutions utilize caching.
My coworker insists that the first option is better since Data access only happens once on the page. The second option seems more logical to me since it will allow me to place the UC on another page without the need for any additional wiring on the page itself. The page and the UC are truly decoupled.
