C Sharp Basics: List Box control in C#

ListBox Controls

These controls are used to show a list of strings from which one or more can be selected at a time. Just like check boxes and radio buttons, the list box provides a means of asking the user to make one or more selections. You should use a list box when at design time you don't know the actual number of values the user can choose from (an example could be a list of co-workers). Even if you know all the possible values at design time, you should consider using a list box if there are a great number of values.

Properties of Listbox

Name	Availability	Description
SelectedIndex	Read/Write	This value indicates the zero-based index of the selected item in the list box. If the list box can contain multiple selections at the same time, this property holds the index of the first item in the selected list.
ColumnWidth	Read/Write	In a list box with multiple columns, this property specifies the width of the columns.
Items	Read-only	The Items collection contains all of the items in the list box. You use the properties of this collection to add and remove items.
MultiColumn	Read/Write	A list box can have more than one column. Use this property the get or set the number of columns in the list box.
SelectedIndices	Read-only	This property is a collection, which holds all of the zero-based indices of the selected items in the list box.
SelectedItem	Read/Write	In a list box where only one item can be selected, this property contains the selected item if any. In a list box where more than one selection can be made, it will contain the first of the selected items.
SelectedItems	Read-only	This property is a collection, which contains all of the items currently selected.
SelectionMode	Read/Write	You can choose between four different modes of selection in a list box: q None: No items can be selected. q One: Only one item can be selected at any time. q MultiSimple: Multiple items can be selected. q MultiExtended: Multiple items can be selected and the user can use the Ctrl, Shift and arrows keys to make selections.
Sorted	Read/Write	Setting this property to true will cause the ListBox to sort the items it contains alphabetically.
Text	Read/Write	We've seen Text properties on a number of controls, but this one works very differently than any we've seen so far. If you set the Text property of the list box control, it searches for an item that matches the text, and selects it. If you get the Text property, the value returned is the first selected item in the list. This property cannot be used if the SelectionMode is None.
CheckedIndicies	Read-only	(CheckedListBox only) This property is a collection, which contains all indexes in the CheckedListBox that is a checked or indeterminate state.
CheckedItems	Read-only	(CheckedListBox only) This is a collection of all the items in a CheckedListBox that are in a checked or indeterminate state.
CheckOnClick	Read/Write	(CheckedListBox only) If this property is true, an item will change its state whenever the user clicks it.
ThreeDCheckBoxes	Read/Write	(CheckedListBox only) You can choose between Checkboxes that are flat or normal by setting this property.

ListBox Methods

Name	Description
ClearSelected	Clears all selections in the ListBox,
FindString	Finds the first string in the ListBox beginning with a string you specify for example FindString("a") will find the first string in the ListBox beginning with 'a'
FindStringExact	Like FindString but the entire string must be matched
GetSelected	Returns a value that indicates whether an item is selected
SetSelected	Sets or clears the selection of an item
ToString	Returns the currently selected item
GetItemChecked	(CheckedListBox only) Returns a value indicating if an item is checked or not
GetItemCheckState	(CheckedListBox only) Returns a value indicating the check state of an item
SetItemChecked	(CheckedListBox only) Sets the item specified to achecked state.
SetItemCheckState	(CheckedListBox only) Sets the check state of an item

ListBox Events

Name	Description
ItemCheck	(CheckedListBox only) Occurs when the check state of one of the list items changes
SelectedIndexChanged	Occurs when the index of the selected item changes

Sample Example for ListBox control-
In following image i have taken 2 ListBox controls and 4 buttons and add items in ListBox one with collection property of this.and change property according to your choice.

My purpose of taking two ListBox is for moving items from listbox1 to ListBox 2 by button click ad show below with single selection and multi selection if user click on button without selecting item from listbox1 then he/she will get alert message for choosing items from ListBox.
Code for this is given below-

Write following code on Single selection Button by double click on button.


private void button1_Click(object sender, EventArgs e)
        {


            if (listBox1.SelectedIndex >= 0)
            {

                string selectitem = listBox1.SelectedItem.ToString();
                listBox2.Items.Add(selectitem);
                
                listBox1.Items.Remove(selectitem);

            }
            else
            {
                MessageBox.Show("Please Choose Item to move", "Warning");
            }
           
       }

Code for moving all items from one ListBox to another.


private void button2_Click(object sender, EventArgs e)
        {
              foreach (string item in listBox1.Items)
                {
                    listBox2.Items.Add(item);
                }
                listBox1.Items.Clear();

        }