THiddenField displays a hidden input field on a Web page.
The value of the input field can be accessed via {@link getValue Value} property.
If upon postback the value is changed, a {@link onValueChanged OnValueChanged}
event will be raised.
/** * Ensure that the ID attribute is rendered and registers the javascript code * for initializing the active control. */ protected function addAttributesToRender($writer) { parent::addAttributesToRender($writer); $writer->addAttribute('id', $this->getClientID()); $this->getActiveControl()->registerCallbackClientScript($this->getClientClassName(), $this->getPostBackOptions()); }