PHP 致命错误：在非对象上调用成员函数 find() 但是我的函数可以工作

PHP Fatal error: Call to a member function find() on a non-object however my function work

提问by user3080061

I am getting this error on Line 71 of my code, however the function of this line is executed correctly and it does what I expect it to do.

我在代码的第 71 行收到此错误，但是此行的功能已正确执行，并且执行了我期望的操作。

However, I noticed that my error log is full of these lines:

但是，我注意到我的错误日志中充满了以下几行：

[09-Dec-2013 14:54:02 UTC] PHP Fatal error: Call to a member function find() on a non-object in /home/sportve/public_html/open_event_common.php on line 71

[09-Dec-2013 14:54:02 UTC] PHP 致命错误：在第 71 行的 /home/sportve/public_html/open_event_common.php 中的非对象上调用成员函数 find()

What I have checked for:

我检查过的内容：

simple_html_dom_parseris already included and this function that Line 71 intend to do is working.

simple_html_dom_parser已包含在内，第 71 行打算执行的此功能正在运行。

Here is Line 71 of my code:

这是我的代码的第 71 行：

$content->find('a.openevent', 0)->innertext = '';

so its confusing as to what is causing this error to appear in my error log file?

所以它令人困惑的是什么导致这个错误出现在我的错误日志文件中？

Edit: here is the full code:

编辑：这是完整的代码：

<?php       
    $url = "static/" . $cat_map[$cat]['url'];
    $html = file_get_html($url);
    $content = $html->find('div#event-pane > div#e' . $event_id, 0);
    $content->find('a.openevent', 0)->innertext = '';
    $content->find('h3.lshtitle', 0)->onclick = '';
    $content->find('h3.lshtitle', 0)->tag = 'div';
    $content->find('div.lshtitle', 0)->class = 'ttl';                
?>

回答by JakeGould

Based on the information you're providing the best and most practical solution is to simply do a check to see if $htmland $contentis empty or not.

根据您提供的信息，最好和最实用的解决方案是简单地检查$html和$content是否为空。

9 times out of 10 when you get a “Call to a member function [whatever the function is] on a non-object”that basically means the object just doesn't exist. Meaning the variable is empty. Here is your code reworked:

当您收到“调用非对象上的成员函数[无论函数是什么]”时，10 次中有 9 次，这基本上意味着该对象不存在。意味着变量为空。这是您重新设计的代码：

$url = "static/" . $cat_map[$cat]['url'];
if (!empty($url)) {
  $html = file_get_html($url);
  if (!empty($html)) {
    $content = $html->find('div#event-pane > div#e' . $event_id, 0);
    if (!empty($content)) {
      $content->find('a.openevent', 0)->innertext = '';
      $content->find('h3.lshtitle', 0)->onclick = '';
      $content->find('h3.lshtitle', 0)->tag = 'div';
      $content->find('div.lshtitle', 0)->class = 'ttl';
    }
  }
}

Also, I added a check to see if the $urlis empty as well.

另外，我还添加了一个检查以查看是否$url为空。