Fill Other ComboBoxes DataSources When Another ComboBox Changes?
Sep 23, 2011
I have a form that has three comboboxes in it, cbxStudy, cbxMethod, & cbxAnalyte. When I call the form I load a data table and use that table to fill the comboboxes. I want to assign a value to cbxStudy, then fill cbxMethod by filtering the data table using the value in cbxStudy, then fill cbxAnalyte by filtering the data table using the values in cbxStudy and cbxMethod.
This code keeps failing when the forms New constructor is called, but once the form is loaded the code works great. I indicated below where the code is failing. It's failing because Me.cbxStudy.SelectedValue is = {System.Data.DataRowView} when the constructor is called even though I set the SelectedValue myself.
Public Class frmSelectMethod
Private cv_dt As New DataTable
Private cv_strPrevValue As String
I have two comboboxes. Depending on what is selected in the first combobox, I want the second combobox to display a different field from a different table within the same database (.mdb).Is this possible?I have the following code, but I get a "Complex DataBinding accepts as a data source either an IList or an IListSource." Error when running the code.
These will all contain the same items and I need to add them at runtime. I know how to loop through the controls, but not sure how to make sure I'm only editing the correct comboboxes. (I will have to do this for 2 more sets of comboboxes with similar naming conventions as well)
1. A dataset contaning all the tables, views and stored procedures from a db in the Data Sources
2. A stored procedure that makes a query using a parameter
3. 2 comboboxes with their DataSources defined
The first combobox gets populated with a stored procedure (with no params, through the Combobox task). When the user selects an item from this combobox this should trigger an event that populates the second combobox with the second stored procedure that requires a parameter.
Since the Dataset is already add to the Data Sources and contains all the procedures I need, I don't wanna to create more datasets or calls to the data base, however I don't know how to set the query using the procedure I already have passing the parameter.
1- Read an Excel Worksheet into DataTable (dt);2- Check 'dt' to know if some columns titles exists;3- Query 'dt' and discard rows where some itens are null or empty;4- After query 'dt', fill some ComboBox.I wrote the code below. It works nice, but I don't know if I'm using best practices when I use Linq to query the data table like I did.
I have 8 comboBoxes and 8 identical items in each comboBox.If I select one of the items in comboBox1, how can make this item to disappear from all other comboBoxes ?
my question is how to filter other comboboxes based in first combobox whish is having same data as all.i am using visual basic 2010 and a ms access database which is connected with code.a vb form have five comboboxes and all comboboxes are field with same data with this code:
Private Sub loadsubject() Dim OleDBC As New OleDbCommand Dim OleDBDR As OleDbDataReader
I have two comboBoxes, one is CountryCombo and second is StateCombo.What I want is the that when i the clicks country combo and select a one country then the States of that the country should get populated in the State Combo.I have tried things many many many but nothing working. Below is my code of how my CountryCombo is getting filled.
query="select CountryName from CountryMaster" if dr.hasRows() {[code]......
I want to choose a value dynamically from comboBox depending of the values selected previously in two comboBoxes.the code that loads the comboBoxes:
Private Sub LightClassComboBox_DropDown(ByVal sender As Object, ByVal e As System.EventArgs) Handles AreaClasificationComboBox.DropDown TrafficDensityComboBox.DropDown,.....
[code]....
The problem is that in the last Sub in the If sentence gives an error of: Null Reference Exception, because the compiler thinks that in that event the data are not loaded, although the data are loaded when loadcomboBoxes sub is executed.
I have a DataSet with a DataTable that has several numeric columns of Data. The numeric data is composed of distances given in U.S. Standard units. I currently have my ComboBoxes set up and working, but I need to expand on what I currently have in two ways.I need to be able to convert the Decimal numbers in my data column being displayed to Fractions, is there a way to do this and maintain databinding? In this case its the Display Member of the data source...I need to be able to display my drop down options in different sets of units... I've written Unit Conversion classes to help take care of this, but I don't know if I can somehow do this as well and maintain databinding? I'd like to convert the units on the display members as well...
Private Sub ComboBox1_SelectedIndexChanged(sender As System.Object, e As System.EventArgs) Handles ComboBox1.SelectionChangeCommitted Select Case ComboBox1.SelectedItem
[code]....
What is the best approach for using ComboBoxes when dealing with issues such as displaying fractions and units...
this is a subset of a previously posted problem, I have narrowed down my issue and am reposting a question from this thread: [URL] I have apparently confused the compiler by renaming some comboboxes in Visual Basic .net express? (See relevant code below) I think the confusion is in who should handle what, with two routines named with variations of ComboBox1 and one handling the other ( it confuses me just trying to interpret it mentally):
I have a form with 4 comboboxes and a button. The first combobox is enabled, but the rest of the controls are disabled. When the form is opened I fill the first combobox (cbxMethod) with a datatable. When the user selects something in cbxMethod the next combobox (cbxStudy) will be filled and so on. When the last combobox (cbxAnalyte) has a selected value I want to enable the button and give it focus so the user can move forward with the program. I basically want to force the user to move from one combobox to the other, until all are filled.I am currently using the SelectionValueChange event, but this event only fires when the user changes the value with their mouse or hits the Enter key, not when the user hits the Tab key.
Public Class frmCalculatedAnalyte Private cv_dt As New DataTable Public Sub New()
Okay so i have set up a database connection and got my combo box to fill from my table but it only fills with the first 4 records even though there are 5. There will be even more records depending on how many bookings are made so i need it to fill with all the records [code]...
I am trying to fill a combobox with data from an xml file. I have it setup on form load to call a loadXMLdata function. In the loadXMLdata function it reads the xml file. I would like to know how I would return each of the elements to populate the combobox. I have mostly done php work and in php i could do an array like this: array[book] = "VB.Net Programming". Is there a way to do something like this with an array such as xmlData("Server 1") = "255.255.255.255"
HTML <config> <connection> <servers>
[Code]...
I know there are some things missing in my code like setting the counter integer.
I have 2 comboboxes. When I choose a country in cboLand I want only the states to show in cboStaat that are associated with the country from cboLand. I tried the code below but I get all different error messages. Perhaps you can see something in my code that I missed.
I am creating a form for entering technical data about a part into an Access database. In the same form I have several ComboBoxs that need to have their lists filled from the same reference table in my database. I have a number and unit field for the twist and bending radius properties. I made the unit fields ComboBoxes and I am trying to bind them to referance table in my database called UnitsLength. The relevant structure is as follows....
Form: NewPartForm Database: CableDataSet Main Table: PartMechanical - with fields: TwistNom, TwistUnits, BendingRadiusNom, BendingRadiusUnits Reference Table: UnitsLength - with fields: Unit, Shorthand, Conversion Factor
First tired the following settings.... Data Source: Other Data Sources > NewPartForm List Instances > CableDatase Display Member: UnitsLength.Shorthand Value Member: UnitsLength.Unit SelectedValue: PartMechanicalBindingSource > [The associated unit field]
But the lists didn't populate.... Then I tried these settings Data Source: UnitsLengthBindingSource Display Member: Shorthand Value Member: Unit SelectedValue: PartMechanicalBindingSource > [The associated unit field] But now every ComboBox displays the same value but still stores the data in the proper field... it just sets them all the same.
I am having a problem with filling a combobox with unique values.Im not very good at vb either so I will explain what I have done so far.
1. I added a combobox to my form called Combobox1
2. I clicked the little triangle widget thing on the ComboBox1 set the dataset to MyDATASETDataSet1
3. Display Member: CurrencyCountry, Value Member: FCode, Selected Value = None
4. I fill MyDATASETDataSet1 when the form loads using:
PricesTableAdapter.ComboBoxQuery(CurrencY_DATABASEDataSet1.Prices) ComboBoxQuery = SELECT DISTINCT [CurrencyCountry], [FCode] FROM [Prices]
The form does not load, i get the error: Failed to enable constraints. One or more rows contain values violating non-null, unique, or foreign-key constraints.If I replace ComboQuery with Fill Query (which is the default fill command) it displays results....but not unique results, i see the same items being repeated throughout the list in the combobox.I guess my questions are:
1. when you fill a dataset do you need to select all the fields when you are creating your query?
2. if i simply wanted to perform the following lookup:
SELECT DISTINCT [CurrencyCountry], [FCode] FROM [Prices]and set the combobox Display Member: CurrencyCountry, Value Member: FCode how would I do this in the code?
3. how can i change my query to display only unique values, distinct doesnt seem to be working?
Can someone tell me what's wrong here: Dim sql As String = "SELECT * FROM courses" Dim con As New MySqlConnection Dim dt As New DataTable(sql) Dim cmd As New MySqlCommand(sql, con)
con.Open() ComboBox1.Items.Add(dt)It doesn't show the courses.
My DataGridView contains three columns, column types are checkbox, textbox and combobox.How can I load a row's combobox when the checkbox in the same row is checked?
I need my application to open an excel document and fill in the combo boxes, with whats in Column A, and then fill in text boxes with whats in Column b etc, but I also neeed to edit those textboxes incase I need to do any edits to the excel document, then click a button, and save those edits to the excel document.
I am using MS Access and i want to fill a combobox cmbFamily with data from a column called family in a dataset called availability and also a combobox called cmbModel with a column called model.
White this code, my ComboBox while by fill, white data frome the database. Now i want to fill the TextBox, on basic frome the selection off the ComboBox
example,.. The ComboBox is filled white meat, in the database is there a price attached
Whene i make a selection in the ComboBox, thane must the attached price show up in the TextBox. My code works for de ComboBox, but not for the TextBox.
