VB.Net controls are located in the Toolbox of the development environment, and you use them to create objects on a form with a simple series of mouse clicks and dragging motions. The ComboBox control , which lets the user choose one of several choices.
The user can type a value in the text field or click the button to display a drop down list. In addition to display and selection functionality, the ComboBox also provides features that enable you to efficiently add items to the ComboBox.
Add item to combobox
How to set the selected item in a comboBox
You can set which item should shown while it displaying in the form for first time.
How to retrieve value from ComboBox
If you want to retrieve the displayed item to a string variable , you can code like this
How to remove an item from ComboBox in VB.Net
You can remove items from a combobox in two ways. You can remove item at a the specified index or giving a specified item by name.
The above code will remove the second item from the combobox.
The above code will remove the item "Friday" from the combobox.
The DropDownStyle property specifies whether the list is always displayed or whether the list is displayed in a drop down. The DropDownStyle property also specifies whether the text portion can be edited.
ComboBox DataSource Property
Programmatically Binding DataSource to ComboBox
You can populate a combo box with a DataSet in a simple way..
Consider an sql query string like...."select au_id,au_lname from authors";
Make a datasource in your program and bind it like the following...
Combobox SelectedIndexChanged event
The SelectedIndexChanged event of a combobox fire when your selection change in the combobox. If you want some actionsg when you change the selection, you can write the code on SelectedIndexChanged event. From the following vb.net code you can understand how to set values in the SelectedIndexChanged event of a combobox. Drag and drop two combobox on the Form and copy and paste the following source code.
VB.Net ComboBox Databinding
You can bind data to a Combobox from various resources like Dataset, List, Enum, Dictionary etc. From the following link you can study more about ... ComboBox Databinding
ComboBox Default Value
How to set a default value for a Combo Box
You can set combobox default value in VB.Net by using SelectedIndex property
Above code set 6th item as combobox default value
How to make a combobox read only
You can make a ComboBox readonly in VB.Net, that means a user cannot write in a combobox but he can select the given values, in two ways. By default, DropDownStyle property of a Combobox is DropDown. In this case user can enter values to combobox. When you change the DropDownStyle property to DropDownList, the Combobox will become read only and user can not enter values to combobox. Second method, if you want the combobox completely read only, you can set comboBox1.Enabled = false.
From the version Visual Studio 2005, some of the controls in VB.Net support Autocomplete feature including the ComboBox controls. From the following link you can see how to make .... Autocomplete ComboBox
The following VB.Net source code add seven days in a week to a combo box while load event of a Windows Form and display the fourth item in the combobox.