Web Server Controls->ASP.NET CheckBoxList Control

Definition and Usage

The CheckBoxList control is used to create a multi-selection check box group.

Each selectable item in a CheckBoxList 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 one of the items changes select status or not. Default is false
CellPadding The space, in pixels, between the cell walls and the check box group
DataSource The data source to use
DataTextField A field in the data source to be displayed in the check box group
DataValueField A field in the data source that specifies the value of each selectable item in the check box group
id A unique id for the control
OnSelectedIndexChanged The name of the function to be executed when one of the items changes select status
RepeatColumns The number of columns to use when displaying the check box group. Default is "1"
RepeatDirection Specifies whether the check box group should be repeated horizontally or vertically. Legal values are "Horizontal" and "Vertical". Default is Vertical
RepeatLayout The layout of the check box group. Can be "Table" or "Flow". Default is Table
runat Specifies that the control is a server control.  Must be set to "server"
TextAlign On which side of the check box the text should appear (right or left)

Examples

CheckBoxList
ASPX Source:

<script  runat="server">
Sub Check(sender As Object, e As EventArgs)
   dim i
   mess.Text="<p>Selected Item(s):</p>"
   for i=0 to check1.Items.Count-1
     if check1.Items(i).Selected then
       mess.Text+=check1.Items(i).Text + "<br />"
     end if
   next
End Sub
</script>

<html>
<body>

<form runat="server">
<asp:CheckBoxList id="check1" AutoPostBack="True"
TextAlign="Right" OnSelectedIndexChanged="Check"
runat="server">
<asp:ListItem>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:CheckBoxList>
<br />
<asp:label id="mess" runat="server"/>
</form>

</body>
</html>


Output Result:
 

 IF you click the checkboxlist "Item 1",it will shows:

Selected Item(s):

Item 1

In this example we declare one CheckBoxList control in an .aspx file. Then we create an event handler for the SelectedIndexChanged event. The selectable list contains six check boxes. When a user checks one of the boxes, the page is immediately posted back to the server, and the Check subroutine is executed. The subroutine loops through the control's Items collection and tests each item's Selected property. The selected items are then displayed in the Label control.

posted on 2007-03-27 09:05  改变热爱  阅读(280)  评论(0)    收藏  举报

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