ComboBox (cbo)

Combobox - Allows the user to either select an item from a drop-down box or enter a different item.

Both the ComboBox and ListBox controls are derived from the ListControl class

Examples

Adding to single column

this.ComboBox1.Items.Add "Item 1"; 
this.ComboBox1.Items.Add "Item 2"; 
this.ComboBox1.SelectedIndex = 0; 

Currently selected item

Obtaining the currently selected item in a combo box.

System.Windows.Forms.MessageBox.Show(this.cboComboBox1.Value) ; 

Select a value

You can use FindString to return the index of the first item that starts with a specified string.

this.cboComboBox1.Text = "Item 2"; 
this.cboComboBox1.SelectedIndex = this.cboComboBox1.FindString("Item 1"); 

Check if a value has been chosen

if (this.cboMyComboBox.SelectedItem == null) 
{} 

DataSource

objDataTable = new System.Data.DataTable; 
objDataTable.TableName = "Applications"; 
objDataTable.Columns.Add("ArticleApplication", GetType(System.String)); 
foreach (objDataRow in clsDatabase.mobjDataSet.Tables("ApplicationNames").Rows) 
{ 
   objDataRowNew = objDataTable.NewRow(); 
   objDataRowNew("ArticleApplication") = objDataRow("ArticleApplication"); 
   objDataTable.Rows.Add(objDataRowNew); 
} 
this.cboComboBox1.DropDownStyle = ComboBoxStyle.DropDownList; 
this.cboComboBox1.DataSource = objDataTable; 
this.cboComboBox1.DisplayMember = "ArticleApplication"; 

Properties

Methods

Events

private void cboComboBox1_SelectedIndexChanged(object sender, System.EventArgs e) 
{ 
   ComboBox myCombo; 
   myComboBox = (ComboBox)sender; 
   myComboBox = this.cboComboBox1; 

   string theValue = (string)myCombo.SelectedItem; 
} 

public partial class Form1 : Form 
{ 
    public Form1() 
    { 
        InitializeComponent(); 

        this.comboBox1.ValueMember = "Property_DayID"; 
        this.comboBox1.DisplayMember = "Property_DayDisplayName"; 

        DayDisplayName oDay; 
        oDay = new DayDisplayName("1", "Mon", "Monday"); 
        this.comboBox1.Items.Add(oDay); 

        oDay = new DayDisplayName("2", "Tue", "Tuesday"); 
        this.comboBox1.Items.Add(oDay); 

        oDay = new DayDisplayName("3", "Wed", "Wednesday"); 
        this.comboBox1.Items.Add(oDay); 
        //this.comboBox1.Items.Add("Wednesday"); 

        this.comboBox1.Text = "Tuesday"; 
        //this.comboBox1.SelectedIndex = this.comboBox1.FindString("Tuesday"); 

    } 
    private void btnComboBox_GetValue_Click(object sender, EventArgs e) 
    { 
        string selectedvalue; 
        selectedvalue = this.comboBox1.Text; 

        System.Windows.Forms.MessageBox.Show(selectedvalue); 
    } 
} 

public class DayDisplayName 
{ 
    public string Property_DayID {  get; set; } 
    public string Property_DayName { get; set; } 
    public string Property_DayDisplayName {  get; set; } 

    public DayDisplayName( 
        string property_DayID, 
        string property_DayName, 
        string property_DayDisplayName) 
    { 
        this.Property_DayID = property_DayID; 
        this.Property_DayName = property_DayName; 
        this.Property_DayDisplayName = property_DayDisplayName; 
    } 
}