zendframework 框架的学习遇到的问题

今天在学习一个例子的时候，应用zend_from来实现表格无论如何也出不来，还报错，错误如下：

Fatal error: Call to a member function setLabel() on a non-object in XXX

我的代码是：

BookFrom 类的实现：

class BookForm extends Zend_Form
{
public function _construct($options=null)
{
parent::_construct($options);
$this->setName('book');
$name = new Zend_Form_Element_Text('name');
$name->setLabel('Name')
->setRequired(true)
->addFilter('StripTags')
->addFilter('StringTrim')
->addValidator('NotEmpty');

$author = new Zend_Form_Element_Text('author');
$author->setLabel('Author');
$author->setRequired(true)
->addFilter('StripTags')
->addFilter('StringTrim')
->addValidator('NotEmpty');

$isbn = new Zend_Form_Element_Text('isbn');
$isbn->setLabel('Isbn');
$isbn->addFilter('StripTags')
->addFilter('StringTrim')
->addValidator('NotEmpty');

$id = new Zend_Form_Element_Hidden('id');
$submit = new Zend_Form_Element_Submit('submit');
$submit->setAttrib('id', 'submitbutton');
$this->addElements(array($id,$name,$author,$isbn,$submit));
}
}

调用BookForm类：

  function addbookAction()
    {
    $this->view->title = "Add new book";
    $form = new BookForm();
    $form->submit->setLabel('Add');  /***************报错提示的是这一行，无法找到对象**********************/
    $this->view->form = $form;
    }

经过查找，利用zend_debug::dump()函数输出$form实例，里边是空的，什么都没有，原来是在BookForm类定义的时候，构造函数打错了：

 function _construct($options=null)  //   construct前边是两个‘_’而不是一个‘_’
parent::_construct($options);//同上

应该改为：

 function __construct($options=null)  
parent::__construct($options)

这部分就可以了。

之后又出现一个错误如下：

Fatal error: Uncaught exception 'Zend_Form_Exception' with message 'Element must be specified by string or Zend_Form_Element instance' in D:\php\WWW\library\library\Zend\Form.php:1065 Stack trace: #0 D:\php\WWW\library\application\models\bookform.php(31): Zend_Form->addElement(Array) #1 D:\php\WWW\library\application\controllers\IndexController.php(23): BookForm->__construct() #2 D:\php\WWW\library\library\Zend\Controller\Action.php(516): IndexController->addbookAction() #3 D:\php\WWW\library\library\Zend\Controller\Dispatcher\Standard.php(308): Zend_Controller_Action->dispatch('addbookAction') #4 D:\php\WWW\library\library\Zend\Controller\Front.php(954): Zend_Controller_Dispatcher_Standard->dispatch(Object(Zend_Controller_Request_Http), Object(Zend_Controller_Response_Http)) #5 D:\php\WWW\library\public\index.php(52): Zend_Controller_Front->dispatch() #6 {main} thrown in D:\php\WWW\library\library\Zend\Form.php on line 1065

看了一下是因为我的bookfrom类的添加元素函数打错了：

$this->addElement(array($id,$name,$author,$isbn,$submit));

这个函数应该是 addElements（array()）; 少打了一个S.以后要多注意函数拼写，原因还是不熟悉一些zend框架提供的函数，需要多加练习