For this you need to use javascript. Instead of using a link for actions, the best way to achieve this is to use a form:
@using (Html.BeginForm("actionname", "controller", FormMethod.Get))
{
@Html.TextBox("textdata")
<input type="submit" value="click me" />
}
, , , .
, javascript ( ), jQuery. URL:
$(function() {
$('#id_of_your_link').click(function() {
var value = $('#textdata').val();
$(this).attr('href', function() {
return this.href += '?param=' + encodeURIComponent(value);
});
});
});