2

可能重复：
试图获取非对象的属性

在为 joomla 2.5 开发自定义组件时，我遇到了一个问题。

我通过 MVC 结构从我的数据库中提取数据。一切正常，除非查询没有返回任何结果。

在我看来，我遇到了一个Trying to get property of non-object错误。

有什么办法可以防止这种情况并向用户显示没有任何结果的好消息吗？

模型部分：

$this->_gallery = array();
            // Load the data
        if (empty( $this->_gallery )) {
            $query = ' SELECT #__gallery.id, user_id, merk, type, name, bouwjaar, vermogen, #__gallery_kleur.kleur, transmissie, #__gallery_benzine.soort AS brandstof, cilinders, motorinhoud, gewicht, link FROM #__gallery LEFT JOIN #__gallery_merk ON #__gallery.merk_id = #__gallery_merk.merk_id LEFT JOIN #__gallery_type ON #__gallery.type_id = #__gallery_type.type_id LEFT JOIN #__gallery_autoinfo ON #__gallery.id = #__gallery_autoinfo.galleryid LEFT JOIN #__gallery_kleur ON #__gallery_autoinfo.kleur = #__gallery_kleur.kleurid LEFT JOIN #__gallery_benzine ON #__gallery_autoinfo.brandstof = #__gallery_benzine.benzineid LEFT JOIN #__users ON #__gallery.user_id = #__users.id LEFT JOIN (SELECT * FROM #__gallery_foto ORDER BY #__gallery_foto.hoofdfoto ASC) as #__gallery_foto ON #__gallery.id = #__gallery_foto.galleryid GROUP BY #__gallery.id ';
            $this->_db->setQuery( $query );
            $this->_db->query();
            $num_rows = $this->_db->getNumRows();

            $this->_gallery = $this->_db->loadObjectList();
        }
        if (!$this->_gallery) {
            $this->_gallery = new stdClass();
            $this->_gallery->id = 0;
        }
    $this->_total = count($this->_gallery); 

    if ($num_rows == 0) {
    if ($this->getState('limit') > 0) {
 $this->_gallery    = array_splice($this->_gallery, $this->getState('limitstart'), $this->getState('limit') );
    }
    }
     return $this->_gallery;

看法：

    // No direct access to this file
defined('_JEXEC') or die('Restricted access');

// import Joomla view library
jimport('joomla.application.component.view');
jimport( 'joomla.html.pagination' );

/**
 * HTML View class for the HelloWorld Component
 */
class GalleryViewGallery extends JView
{
    // Overwriting JView display method
    function display($tpl = null) 
    {
        $gallery = $this->get( 'Gallery' );
        $this->assignRef( 'gallery',    $gallery );

        $this->items = $this->get('Gallery');
        $this->pagination = $this->get('Pagination'); 

        // Check for errors.
        if (count($errors = $this->get('Errors'))) 
        {
            JError::raiseError(500, implode('<br />', $errors));
            return false;
        }
        // Display the view
        parent::display($tpl);
    }
}

默认.php：

// No direct access to this file
defined('_JEXEC') or die('Restricted access');
//$document = &JFactory::getDocument(); $document->addStyleSheet('components'.DS.'com_gallery'.DS.'css'.DS.'gallery.css');
$document = &JFactory::getDocument(); $document->addStyleSheet('components/com_gallery/css/gallery.css');
?>
<p>
In onderstaande overzicht wordt overzicht van galleries getoond, ben op je zoek naar iets specifieks ?. Gebruik dan het zoekscherm aan de linkerkant van deze pagina om een aangepast overzicht te tonen.
</p>
<?php
$count = '1';

foreach($this->gallery as $gallery){
if($count == '0'){
    echo 'Geen resultaat';
}else{
?>
<div class="gallery_wrapper">
<?php
if($gallery->merk OR $gallery->type > Null){
echo "<div class=\"gallery_merktype\">";
echo "<a href='gallerie?view=gallerydetail&amp;gallery=" . $gallery->id . "' target='_self'>";
echo "<H1>";
echo $gallery->merk;
echo " ";
echo $gallery->type;
echo "</H1>";
echo "</a>";
echo "</div>";
}
//Weergeven afbeelding, bepaling maximale hoogte en breedte gebeurt in CSS.
if($gallery->link > Null){
echo "<div class=\"gallery_foto\">";
echo "<div class=\"gallery_foto_clip\">";
echo "<a href='gallerie?view=gallerydetail&amp;gallery=" . $gallery->id . "' target='_self'><img src='../galleryimage/thumb/" . $gallery->link . "' width='200px' alt='Afbeelding'/></a>";
echo "</div></div>";
}               
?>
<div class="gallery_wrapper_info">
<?php
//Weergeven gallery gegevens.
if($gallery->bouwjaar > Null){
echo "<div class=\"gallery_info_title\">Bouwjaar:</div>";
echo "<div class=\"gallery_info_values\">";
echo $gallery->bouwjaar;
echo "</div>";
}
if($gallery->vermogen > Null){
echo "<div class=\"gallery_info_title\">Vermogen:</div>";
echo "<div class=\"gallery_info_values\">";
echo $gallery->vermogen;
echo "</div>";
}
if($gallery->kleur > Null){
echo "<div class=\"gallery_info_title\">Kleur:</div>";
echo "<div class=\"gallery_info_values\">";
echo $gallery->kleur;
echo "</div>";
}
if($gallery->transmissie > Null){
echo "<div class=\"gallery_info_title\">Transmissie:</div>";
echo "<div class=\"gallery_info_values\">";
echo $gallery->transmissie;
echo "</div>";
}
if($gallery->brandstof > Null){
echo "<div class=\"gallery_info_title\">Brandstof:</div>";
echo "<div class=\"gallery_info_values\">";
echo $gallery->brandstof;
echo "</div>";
}               
if($gallery->cilinders > Null){
echo "<div class=\"gallery_info_title\">Cilinders:</div>";
echo "<div class=\"gallery_info_values\">";
echo $gallery->cilinders;
echo "</div>";
}
if($gallery->motorinhoud > Null){
echo "<div class=\"gallery_info_title\">Motorinhoud:</div>";
echo "<div class=\"gallery_info_values\">";
echo $gallery->motorinhoud;
echo "</div>";
}
if($gallery->gewicht > Null){
echo "<div class=\"gallery_info_title\">Gewicht:</div>";
echo "<div class=\"gallery_info_values\">";
echo $gallery->gewicht;
echo "</div>";
}
?>
<div class="gallery_bekijken">
<H2><a href="index.php/gallerie?view=gallerydetail&amp;gallery=<?php echo $gallery->id; ?>" target="_self">Bekijk Gallery</a></H2>
</div>
</div>

</div>


<?php   
}
}
?>

<form method="post" name="limiet">
<?php echo $this->pagination->getPagesLinks(); ?>
<center>
<?php echo $this->pagination->getLimitbox(); ?>
</center>
</form>

太好了！，我已经尝试过以下方式，它对我有用：

if(is_object($this->gallery)){
echo "No result";
}else{

//DATA

}

作为记录：

填充数组的 print_r：

Array ( [0] => stdClass Object ( [id] => 146 [user_id] => 861 [merk] => Seat [type] => Leon [name] => Danny [bouwjaar] => 2004 [vermogen] => 190 [kleur] => Geel [transmissie] => Handgeschakeld [brandstof] => Diesel [cilinders] => 4 [motorinhoud] => 1900 [gewicht] => 1210 [link] => p1793sjnq51u373r12qdobs1d2b2.jpg ) )

还有一个空的：

stdClass Object ( [id] => 0 )

虽然我之前错过了一些东西，但在模型中我将限制变量调整为“0”而不是默认的“5”进行测试。

如果我把它放回“5”，当查询没有返回任何结果时，我会得到一个 array_splice 错误。当有数据时，它可以完美运行。

也许我在这里也做错了什么？

我的模型中的一段代码：

$this->_gallery = array();
            // Load the data
        if (empty( $this->_gallery )) {
            $query = ' SELECT #__gallery.id, user_id, merk, type, name, bouwjaar, vermogen, #__gallery_kleur.kleur, transmissie, #__gallery_benzine.soort AS brandstof, cilinders, motorinhoud, gewicht, link FROM #__gallery LEFT JOIN #__gallery_merk ON #__gallery.merk_id = #__gallery_merk.merk_id LEFT JOIN #__gallery_type ON #__gallery.type_id = #__gallery_type.type_id LEFT JOIN #__gallery_autoinfo ON #__gallery.id = #__gallery_autoinfo.galleryid LEFT JOIN #__gallery_kleur ON #__gallery_autoinfo.kleur = #__gallery_kleur.kleurid LEFT JOIN #__gallery_benzine ON #__gallery_autoinfo.brandstof = #__gallery_benzine.benzineid LEFT JOIN #__users ON #__gallery.user_id = #__users.id LEFT JOIN (SELECT * FROM #__gallery_foto ORDER BY #__gallery_foto.hoofdfoto ASC) as #__gallery_foto ON #__gallery.id = #__gallery_foto.galleryid GROUP BY #__gallery.id ';
            $this->_db->setQuery( $query );
            $this->_gallery = $this->_db->loadObjectList();
        }
        if (!$this->_gallery) {
            $this->_gallery = new stdClass();
            $this->_gallery->id = 0;
        }
    $this->_total = count($this->_gallery); 

    if ($this->getState('limit') > 0) {
     $this->_gallery    = array_splice($this->_gallery, $this->getState('limitstart'), $this->getState('limit') );
    }
     return $this->_gallery;
}

当没有结果和限制设置为 5 时，我认为错误：

Warning: array_splice() expects parameter 1 to be array, object given in

Print_R 没有返回结果，但我认为这很明显。

4

1 回答 1

1

检查对象是否有数据。您可以使用以下组合

isset- Determine if a variable is set and is not NULL

is_null - Finds whether a variable is NULL

empty — Determine whether a variable is empty

is_array — Finds whether a variable is an array 

is_object — Finds whether a variable is an object

您可以使用类似的东西（如果行数为 0，则将对象设置为 null）。

If(!is_null($this->gallery))
{
//show data
}
else
{
//show a msg
}

你可以检查是否$this->gallery是一个对象。

If(is_object($this->gallery))
{
//show data
}
else
{
//show a msg
}

根据结果​​集明智地选择上述内容。如果你可以发布一个print_r我可以告诉你你必须使用什么。

关于问题的更新

警告：array_splice() 期望参数 1 是数组，对象在

它可能不起作用的原因是因为$this->_gallery可能不是数组。

stdClass Object ( [id] => 0 ) <-- 这是一个对象而不是数组。如果要调用 array_slice() 函数，第一个参数应该是一个数组。

要检查某物是否为数组，您可以执行以下操作：

is_array($this->_gallery); // returns true or false

如果是数组，则可以调用array_slice().

希望这可以帮助。如果你有任何问题在这里问。

于 2012-11-01T16:02:38.827 回答