三水之都

<?xml version="1.0" encoding="UTF-8"?>
<config>
	<circle>2</circle>
</config>

$config_file = dirname(__FILE__).'/config.xml';		//config.xml的绝对地址
$xml = simplexml_load_file($config_file);

$circle = new Typecho_Widget_Helper_Form_Element_Text('circle', null, (string)$xml->circle, _t('更新周期(天)'));
$form->addInput($circle->addRule('isInteger', _t('更新周期必须是纯数字')));

$request = Typecho_Request::getInstance();
if ($request->isPost()) {
	 /**
	  * 更新配置文件
	  */
        $xml->circle = $request->get('circle');
        	
        $xml = $xml->asXML();
        	
        $fp = fopen($config_file, 'wb');
        fwrite($fp, $xml);   //向config.xml中写数据
        fclose($fp);
}

object(SimpleXMLElement)#1 (11) {
  ["circle"]=>
  string(1) "2"
}

object(SimpleXMLElement)#2 (1) {
  [0]=>
  string(1) "2"
}