初始化一個類別非常容易，例如下面的程式碼
MYCLASS_PROTERTY_* 這個相關(guān)是 define 的巨集字串

<code>zend_class_entry *myclass_ce;

zend_function_entry myclass_methods[] = {
    PHP_FE_END
};

PHP_MINIT_FUNCTION(myext)
{

    zend_class_entry ce;

    INIT_CLASS_ENTRY(ce, <span>"MyClass"</span>, myclass_methods);
    myclass_ce = zend_register_internal_class(&ce TSRMLS_CC);

    zend_<span>declare</span>_class_constant_string(myclass_ce, ZEND_STRL(MYCLASS_PROTERTY_NAME_VERSION), PHP_SLIM_VERSION);
    zend_<span>declare</span>_property_null(myclass_ce, ZEND_STRL(MYCLASS_PROTERTY_NAME_CONTAINER), ZEND_ACC_PUBLIC TSRMLS_CC);
    zend_<span>declare</span>_property_null(myclass_ce, ZEND_STRL(MYCLASS_PROTERTY_NAME_APPS), ZEND_ACC_STATIC|ZEND_ACC_PROTECTED TSRMLS_CC);
    zend_<span>declare</span>_property_null(myclass_ce, ZEND_STRL(MYCLASS_PROTERTY_NAME_NAME), ZEND_ACC_PROTECTED TSRMLS_CC);
    zend_<span>declare</span>_property_null(myclass_ce, ZEND_STRL(MYCLASS_PROTERTY_NAME_ERROR), ZEND_ACC_PROTECTED TSRMLS_CC);
    zend_<span>declare</span>_property_null(myclass_ce, ZEND_STRL(MYCLASS_PROTERTY_NAME_NOTFOUND), ZEND_ACC_PROTECTED TSRMLS_CC);
    zend_<span>declare</span>_property_null(myclass_ce, ZEND_STRL(MYCLASS_PROTERTY_NAME_MIDDLEWARE), ZEND_ACC_PROTECTED TSRMLS_CC);

    <span>return</span> SUCCESS;
}</code>

以上的程式碼都是一些簡單的屬性。
當想要為myclass這個類別初始化一個陣列的屬性的時候，失敗了，相對於php的程式碼如下

<code><span><span>class</span><span>MyClass</span> {
    public $myArray = array<span>()</span>;
}


/* 對應的<span>C</span>代碼 */

zval *myArray;
<span>MAKE_STD_ZVAL</span><span>(<span>myArray</span>)</span>;
array_init<span>(<span>myArray</span>)</span>;

zend_declare_property<span>(<span>myclass_ce</span>, <span>ZEND_STRL(MYCLASS_PROTERTY_NAME_MYCLASS)</span>, <span>myArray</span>, <span>ZEND_ACC_PUBLIC</span><span>TSRMLS_CC</span>)</span>;</span></code>

上面這段C程式碼變異的時候並沒有發(fā)現(xiàn)什麼問題，在執(zhí)行new MyClass() 的時候就出現(xiàn)問題了，報錯如下：

<code>Internal zval<span>'s</span> can<span>'t</span> be arrays, objects <span>or</span> resources</code>

翻看zend的源代碼如下：

<code><span>if</span> (ce-><span><span>type</span> & <span>ZEND_INTERNAL_CLASS</span>) <span>{
     <span>switch</span>(<span>Z_TYPE_P(property)</span>) {
         <span>case</span><span>IS_ARRAY</span>:
         <span>case</span><span>IS_CONSTANT_ARRAY</span>:
         <span>case</span><span>IS_OBJECT</span>:
         <span>case</span><span>IS_RESOURCE</span>:
             <span>zend_error</span>(<span>E_CORE_ERROR</span>, "<span>Internal</span><span>zval's</span><span>can't</span><span>be</span><span>arrays</span>, <span>objects</span><span>or</span><span>resources</span>");
             <span>break</span>;
         <span>default</span>:
             <span>break</span>;
     }</span></span>
 }</code>

當我們在調(diào)用zend_register_internal_class的時候，myclass_ce 已經(jīng)初始化為ZEND_INTERNAL_CLASS了，而此時的zend_declare_property所以產(chǎn)生了這樣的錯誤。

為什麼會產(chǎn)生這樣的錯誤呢？

我搜尋下得到的結(jié)果是：http://grokbase.com/t/php/php-internals/07a4b14xvb/php-dev-how-declare-protected-array-property-at-internal-class-properly 這個是2007年的結(jié)果，我這個是採用的php5.4版本的，暫時還是有這個問題的，文中也給了變相實現(xiàn)數(shù)組屬性的方法，透過在構(gòu)造函數(shù)裡面實現(xiàn)。

<code>PHP_METHOD(myclass, __construct) {
    zval <span>*apps</span>, <span>*pThis</span>;
    pThis = getThis();
    MAKE_STD_ZVAL(apps);
    array_init(apps);
    add_property_zval_ex(pThis, ZEND_STRL(SLIM_SLIM_PROTERTY_NAME_APPS), apps);
}</code>

這種實作的方式對應的php程式碼

<code><span><span>class</span><span>MyClass</span> {</span><span><span>function</span><span>__construct</span><span>()</span> {</span><span>$this</span>->app = <span>array</span>();  
    }
}</code>

以上就介紹了php擴充開發(fā)筆記（1）創(chuàng)建類別的陣列屬性，包含了方面的內(nèi)容，希望對PHP教學有興趣的朋友有幫助。