在代码的一部分中,设置$this->值的值,并根据我的测试正确设置该值.

但是,稍后在同一代码中,$this->值为空.

这是代码：

<?PHP

class Padd_Input_Advertisement {

    protected $keyword;
    protected $value;
    protected $name;
    protected $description;

    function __construct($keyword,$name,$description='') {
        $this->keyword = $keyword;
        $this->value = unserialize(get_option($keyword));
        $this->name = $name;
        $this->description = $description;
    }

    public function get_keyword() {
        return $this->keyword;
    }

    public function set_keyword($keyword) {
        $this->keyword = $keyword;
    }

    public function get_value() {
        return $this->value;
    }

    public function set_value($value) {
        $this->value = $value;
    }

    public function get_name() {
        return $this->name;
    }

    public function set_name($name) {
        $this->name = $name;
    }

    public function get_description() {
        return $this->description;
    }

    public function set_description($description) {
        $this->description = $description;
    }

    public function  __toString() {

        $strHTML  = '';
        $strHTML .= '<tr valign="top">';
        $strHTML .= '   <th scope="row"><label for="' . $this->keyword . '">' . $this->name . '</label></th>';
        $strHTML .= '   <td>';
        $strHTML .= '       <label for="' . $this->keyword. '_alt_desc">Short Description</label><br />';
        $strHTML .= '       <input name="' . $this->keyword . '_alt_desc" type="text" id="' . $this->keyword . '_alt_desc" value="' . $this->value->get_alt_desc() . '" size="80" /><br />';
        $strHTML .= '       <label for="' . $this->keyword. '_img_url">Image URL</label><br />';
        $strHTML .= '       <input name="' . $this->keyword . '_img_url" type="text" id="' . $this->keyword . '_img_url" value="' . $this->value->get_img_url() . '" size="80" /><br />';
        $strHTML .= '       <label for="' . $this->keyword. '_web_url">Website</label><br />';
        $strHTML .= '       <input name="' . $this->keyword . '_web_url" type="text" id="' . $this->keyword . '_web_url" value="' . $this->value->get_web_url() . '" size="80" />';
        $strHTML .= '       <br /><small>' . $this->description . '</small>';
        $strHTML .= '   </td>';
        $strHTML .= '</tr>';
        return $strHTML;
    }

}

?>

在函数__construct的顶部,设置了值,我确认会发生这种情况.

但是,在底部函数函数__toString中,$this->值为空.

知道是什么原因引起的吗？

编辑

因此,回顾一下,$this->值在__construct函数中正确设置,但在__toString函数中是空白的.

编辑2

我还应该提到__construct函数中设置的其他变量在__toString函数中工作,就像$this->关键字一样.这是jut $this->值空白.

编辑3
这个类就是这样调用的

$padd_options['advertisements'] = array(
    new Padd_Input_Advertisement(
        PADD_NAME_SPACE . '_ads_125125_1','Square Ad 1 (125x125)','The advertisement will be posted at the side bar.'
    ),new Padd_Input_Advertisement(
        PADD_NAME_SPACE . '_ads_125125_2','Square Ad 2 (125x125)',new Padd_Input_Advertisement(
        PADD_NAME_SPACE . '_ads_125125_3','Square Ad 3 (125x125)',new Padd_Input_Advertisement(
        PADD_NAME_SPACE . '_ads_125125_4','Square Ad 4 (125x125)',);