Creo que deberias usar javascript, algo asi:
Código Javascript
:
Ver original<script type="text/javascript" language="javascript">
function ChangeCheckBoxState(id, checkState) {
var cb = document.getElementById(id);
if (cb != null)
cb.checked = checkState;
}
function ChangeAllCheckBoxStates(checkState) {
// Toggles through all of the checkboxes defined in the CheckBoxIDs array
// and updates their value to the checkState input parameter
if (CheckBoxIDs != null) {
for (var i = 0; i < CheckBoxIDs.length; i++)
ChangeCheckBoxState(CheckBoxIDs[i], checkState);
}
}
function ChangeHeaderAsNeeded() {
// Whenever a checkbox in the GridView is toggled, we need to
// check the Header checkbox if ALL of the GridView checkboxes are
// checked, and uncheck it otherwise
if (CheckBoxIDs != null) {
// check to see if all other checkboxes are checked
for (var i = 1; i < CheckBoxIDs.length; i++) {
var cb = document.getElementById(CheckBoxIDs[i]);
if (!cb.checked) {
// Whoops, there is an unchecked checkbox, make sure
// that the header checkbox is unchecked
ChangeCheckBoxState(CheckBoxIDs[0], false);
return;
}
}
// If we reach here, ALL GridView checkboxes are checked
ChangeCheckBoxState(CheckBoxIDs[0], true);
}
}
</script>