調用一個成員函數的createElement（）在PHP

Question

一個非對象我想創建XML文件類似的東西使用XML DOM解析器

<dict> 
<key>outlineThickness</key>  <real>0.0</real> 
<key>repeat</key>  <false /> 
<key>rotation</key>  <string>no</string> 
</dict> 

，但我的代碼告訴我的錯誤 注意：未定義的變量：dom在第18行C：\ wamp \ www \ iwatermark \ xmlapi \ xmlapi.php 致命錯誤：調用C：\ wamp \ www \ iwatermark \ xmlapi \ xmlapi中的非對象的成員函數createElement（） .php on line 18.

這就是我寫的

<?php 

class XMLApi 
{ 
    private $dom = null; 
    private $root = null; 
    public function __construct() 
    { 
     $dom = new DOMDocument("1.0"); 
     $dom->formatOutput = TRUE; 

     $root = $dom->createElement("dict"); 
     $dom->appendChild($root); 
    } 

    public function createNode($keyname, $keytext, $valuename, $valuetext) 
    { 
     $item = $dom->createElement($keyname); 
     $root->appendChild($item); 

     // create text node 
     $text = $dom->createTextNode($keytext); 
     $item->appendChild($text); 

     if($valuename == "true" || $valuename == "false") 
     { 
      $item = $dom->createElement($valuename); 
      $root->appendChild($item); 
     } 
     else 
     { 
      $item = $dom->createElement($valuename); 
      $root->appendChild($item); 

      // create text node 
      $text = $dom->createTextNode($valuetext); 
      $item->appendChild($text); 
     } 
     // create child element 


    } 

    public function ending() 
    { 
     $dom->save("test01.xml"); 
    } 
} 





$obj = new XMLApi(); 
$obj->createNode("key","outlineThickness","real","0.0"); 
$obj->createNode("key","repeat","false",""); 
$obj->createNode("key","rotation","string","no"); 
$obj->ending(); 




header("Location: "."test01.xml"); 

?> 

Answer 1

從類內部訪問類變量時，需要使用$this->dom。