haliphax

If you're working with a GridView control where you've built a CheckBox control into each row of data displayed, odds are, it would be convenient for your users if a "Check/Un-check All" option was available. The following example will show how to do just that; and with only the tiniest bit of jQuery script!

First, we'll build a GridView control similar to this, with an <input /> check box in the HeaderTemplate corresponding to each row's CheckBox control:

ASP.NET Code:

<asp:GridView ID="myGridView" runat="server">
	<Columns>
		<asp:TemplateField>
			<HeaderTemplate>
				<input type="checkbox" id="chkAll" />
			</HeaderTemplate>
			<ItemTemplate>
				<asp:CheckBox ID="myCheckBox" runat="server" />
			</ItemTemplate>
		</asp:TemplateField>
		<!– other fields here … –>
	</Columns>
</asp:GridView>

Obviously, the chkAll item needs some client-side script before it's going to do anything meaningful. You could either place the following jQuery code into the onchange event for chkAll, or we can wire up an event handler in a <script> block:

Javascript (jQuery) code:

$("#chkAll").change(function () {
  $("#<%=myGridView.ClientID%> input[type=checkbox]").attr(
    "checked",
    $(this).attr("checked"),
  );
});

It's as simple as that! Checking or un-checking chkAll will cause each CheckBox control within the GridView to inherit its value. If you've separated your *.js files from your *.aspx files, you can attach a CSS class to your GridView and select based on that (rather than using the GridView's ClientID property).