DOMDocument和DOMXPath错误

Question

我想使用DOMDocument映射所有区域形状标签，但是我的代码仅适用于DIV，而不适用于map标签。 为什么？ 这是我的代码。 我得到的问题是返回空字符串。

码：

$DOM = new DOMDocument; 
$DOM->loadHTML($conteudo['ambiente']->mapeamento);
$xpath = new DOMXPath($DOM);
$tags = $xpath->query('//area');
foreach ($tags as $tag) {
    var_dump(trim($tag->nodeValue));
}

示例代码：

<map name="Map" id="Map">
  <area shape="poly" coords="0,916,86,880,527,854,520,819,536,818,547,818,564,819,563,855,627,851,620,813,640,810,653,810,664,813,660,847,804,837,816,820,766,823,756,821,752,815,743,414,755,407,782,406,1282,430,1286,432,1279,775,1290,775,1306,775,1311,777,1305,804,1337,801,1335,775,1341,772,1353,772,1370,774,1370,797,1711,793,1792,802,1789,365,1795,360,1804,0,-1,0,0,916,1,915,1144,804" href="#" />
  <area shape="poly" coords="1143,803,1271,792,1274,808,1151,816,1143,812,1142,803" href="#" />
  <area shape="poly" coords="1800,-1,2052,-1,2054,1033,1907,1003,1909,973,2024,967,2016,315,1866,328,1794,360,1803,2" href="#" />
  <area shape="poly" coords="1899,975,1894,1002,1876,998,1879,974,1901,974" href="#" />
</map>

Answer 1

您的<area>标记没有内容，因此输出正确。 如果要获取coords属性的值，则应使用

$tags = $xpath->query('//area/@coords');