Web Server Controls->ASP.NET ListBox Control
Definition and Usage
The ListBox control is used to create a single- or multi-selection drop-down list.
Each selectable item in a ListBox control is defined by a ListItem element!
Tip: This control supports data binding!
Properties
| Property | Description |
|---|---|
| AutoPostBack | A Boolean value that specifies whether the form should be posted immediately after the index of the selected item has changed or not. Default is false |
| BorderColor | Specifies the color of the border around the drop-down list |
| BorderStyle | Specifies the style of the border around the drop-down list |
| BorderWidth | Specifies the width of the border around the drop-down list |
| DataSource | The data source to use |
| DataTextField | A field in the data source to be displayed in the drop-down list |
| DataValueField | A field in the data source that specifies the value of each selectable item in the drop-down list |
| id | A unique id for the control |
| OnSelectedIndexChanged | The name of the function to be executed when the index of the selected item has changed |
| Rows | Specifies the height of the control |
| runat | Specifies that the control is a server control. Must be set to "server" |
| SelectionMode | Allows single or multiple selections. Legal values: "single" and "multiple". Default is "single" |
Examples
Listbox
ASPX Source:
| <script runat="server"> Sub submit(Sender As Object,e As EventArgs) mess.Text="You selected " & drop1.SelectedItem.Text End Sub </script> <html> <body> <form runat="server"> <asp:ListBox id="drop1" rows="3" runat="server"> <asp:ListItem selected="true">Item 1</asp:ListItem> <asp:ListItem>Item 2</asp:ListItem> <asp:ListItem>Item 3</asp:ListItem> <asp:ListItem>Item 4</asp:ListItem> <asp:ListItem>Item 5</asp:ListItem> <asp:ListItem>Item 6</asp:ListItem> </asp:ListBox> <asp:Button Text="Submit" OnClick="submit" runat="server" /> <p><asp:label id="mess" runat="server" /></p> </form> </body> </html> |
Output Result:
If you select the ListBox "Item 6" and the click the button "Submit",It will show:
|
You selected Item 6 |
In this example we declare one ListBox control in an .aspx file. Then we create an event handler for the Click event which displays some text and the selected item, in a Label control.
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