ListBox (lsb)

ListBox - Allows the user to select an item from a list of items.

Both the ComboBox and ListBox controls are derived from the ListControl class
The listindex property in a listbox control has been replaced with the "selectedindex" property.

Examples

Adding Items

listBox1.ClearSelected(); 
listBox1.BeginUpdate(); 
listBox1.Items.Add("Item 1"); 
listBox1.Items.Add("Item 3"); 
listBox1.Items.Add("Item 4"); 
listBox1.Items.Add("Item 5"); 
listBox1.Items.Add("Item 6"); 
listBox1.Items.Insert(1, "Item 2"); 
listBox1.EndUpdate(); 

Single Selection

Gets or sets the selected item.

myListBox.SelectedIndex = 1; 

Returns the string of the currently selected item.

string sItem = this.myListBox.SelectedItem.ToString(); 
System.Windows.Forms.MessageBox.Show(sItem); 

For all the items in the listbox

foreach (string sItem in this.myListBox.Items) 
{ 
    System.Windows.Forms.MessageBox.Show(sItem); 
} 

Alternatively

for (int iItem = 0; iItem < this.myListBox.Items.Count; iItem++) 
{ 
    string sItem = this.myListBox.Items[iItem]).ToString(); 
    System.Windows.Forms.MessageBox.Show(sItem); 
} 

Multiple Selection

Selecting and unselecting multiple items.
This will not work unless the tab is currently selected (i.e. the listbox is visible)
You can use SelectedIndex instead for a single selection

listBox1.SetSelected(1, true); 
listBox1.SelectedIndex = 1; 

Test if the last item in the list is selected

bool bIsSelected = this.listBox1.GetSelected(this.listBox1.Items.Count - 1); 
System.Windows.Forms.MessageBox.Show(bIsSelected.ToString()); 

For all the items that are currently selected.

foreach (string sItem in this.listBox1.SelectedItems) 
{ 
     System.Windows.Forms.MessageBox.Show(sItem); 
} 

Convert Items to an IList<string>

You must include Using System.Linq;

System.Collections.Generic.List<string> myCollection; 
myCollection = (this.listBox1.Items).Cast<string>().ToList(); 
System.Windows.Forms.MessageBox.Show(myCollection[2]); 

Restrict ListBox Selection

    public partial class MyForm : Form 
    { 
        private int[] aSelectedIndexes = new int[5]; 

        public Form1() 
        { 
            InitializeComponent(); 
        } 

        private void Form1_Load(object sender, EventArgs e) 
        { 
            this.listBox1.ClearSelected(); 
            this.listBox1.BeginUpdate(); 
            this.listBox1.Items.Add("Item 1"); 
            this.listBox1.Items.Add("Item 3"); 
            this.listBox1.Items.Add("Item 4"); 
            this.listBox1.Items.Add("Item 5"); 
            this.listBox1.Items.Add("Item 6"); 
            this.listBox1.Items.Insert(1, "Item 2"); 
            this.listBox1.EndUpdate(); 

            this.listBox1.SelectionMode = System.Windows.Forms.SelectionMode.MultiSimple; 
        } 

        private void listBox1_SelectedIndexChanged(object sender, EventArgs e) 
        { 
            bool bfound; 
            int iSelectedIndex; 

            if (this.listBox1.SelectedItems.Count < 5) 
            { 
                for (int iselectedcount = 0; iselectedcount < this.listBox1.SelectedIndices.Count; iselectedcount++) 
                { 
                    aSelectedIndexes[iselectedcount] = this.listBox1.SelectedIndices[iselectedcount]; 
                } 
            } 
            else 
            { 
                System.Windows.Forms.MessageBox.Show("You are only allowed to select 4 items"); 

                for (int iselectedcount = 0; iselectedcount < this.listBox1.SelectedIndices.Count; iselectedcount++) 
                { 
                    bfound = false; 
                    iSelectedIndex = this.listBox1.SelectedIndices[iselectedcount]; 

                    for (int iarraycount = 0; iarraycount < aSelectedIndexes.GetUpperBound(0); iarraycount++) 
                    { 
                        if (aSelectedIndexes[iarraycount] == iSelectedIndex) 
                        { 
                            bfound = true; 
                        } 
                    } 

                    if (bfound == false) 
                    { 
                        this.listBox1.SetSelected(iSelectedIndex, false); 
                        return; 
                    } 
                } 
            } 
} 

Properties

Methods

Methods - Single Selection

Methods - Multiple Selection

Events