检测mp4文件(Detect mp4 files)

 这是您目前正在考虑的非常糟糕的解决方案： 
 
<span\b[^<>]*\bid="ctl00_MainContent_ListView2_ctrl2_ctl01_[^"]*"[^<>]*475px;">(.*?)</span><br\s*/>
 
 见演示 
 
 它确保我们找到了一个<span>标签，并且有一个以ctl00_MainContent_ListView2_ctrl2_ctl01_开头的id属性，并且有一些以475px;结尾的属性（你知道它是style ） 475px; ，然后我们只捕获任何截至</span>标记的内容。 
 
 您可以使用DOM和XPath来实现这一点，这是一个更安全的解决方案，它使用与上面相同的逻辑： 
 
$html = "<span id=\"ctl00_MainContent_ListView2_ctrl2_ctl01_Label17\" class=\"vehicledetailTable\" style=\"display:inline-block;width:475px;\">OWNED</span><br />"; 
$dom = new DomDocument();
$dom->loadHTML($html);
$xpath = new DOMXPath($dom);
$spans = $xpath->query("//span[starts-with(@id,'ctl00_MainContent_ListView2_ctrl2_ctl01_') and @class='vehicledetailTable'  and contains(@style,'475px;')]");
$data = array();
foreach ($spans as $span) {
    array_push($data, $span->textContent);
}
print_r($data);
 
 输出： [0] => OWNED 
 
 注意XPath表达式包含3个条件，随意修改任何： 
 
 
 
 //span - 获取所有span标签 
 
 
 starts-with(@id,'ctl00_MainContent_ListView2_ctrl2_ctl01_') - 有一个属性id ，其值以ctl00_MainContent_ListView2_ctrl2_ctl01_ 
 
 
 @class='vehicledetailTable' - 并且class属性的值等于vehicledetailTable 
 
 
 contains(@style,'475px;') - 并且有一个style属性，其值包含475px; 。 
 
 
 条件包含在[...] ，并与or或and 。 它们也可以用圆括号分组。 您也可以使用not(...)来反转条件。 XPath在这种情况下非常有用。 

Here is a very poor solution that you are currently considering:
 
<span\b[^<>]*\bid="ctl00_MainContent_ListView2_ctrl2_ctl01_[^"]*"[^<>]*475px;">(.*?)</span><br\s*/>
 
See demo
 
It makes sure we found a <span> tag and there is id attribute starting with ctl00_MainContent_ListView2_ctrl2_ctl01_, and there is some attribute (and you know it is style) ending with 475px;, and then we just capture anything up to the closing </span> tag.
 
You can get this with DOM and XPath, which is a much safer solution that uses the same logic as above:
 
$html = "<span id=\"ctl00_MainContent_ListView2_ctrl2_ctl01_Label17\" class=\"vehicledetailTable\" style=\"display:inline-block;width:475px;\">OWNED</span><br />"; 
$dom = new DomDocument();
$dom->loadHTML($html);
$xpath = new DOMXPath($dom);
$spans = $xpath->query("//span[starts-with(@id,'ctl00_MainContent_ListView2_ctrl2_ctl01_') and @class='vehicledetailTable'  and contains(@style,'475px;')]");
$data = array();
foreach ($spans as $span) {
    array_push($data, $span->textContent);
}
print_r($data);
 
Output: [0] => OWNED
 
Note that the XPath expression contains 3 conditions, feel free to modify any:
 
 
 
//span - get all span tags that 
 
 
starts-with(@id,'ctl00_MainContent_ListView2_ctrl2_ctl01_') - have an attribute id with value starting with ctl00_MainContent_ListView2_ctrl2_ctl01_
 
 
@class='vehicledetailTable' - and have class attribute with value equal to vehicledetailTable
 
 
contains(@style,'475px;') - and have a style attribute whose value contains 475px;.
 
 
Conditions are enclosed into [...] and are joined with or or and. They can also be grouped with round brackets. You can also use not(...) to invert the condition. XPath is very helpful in such situations.