c - miniXML 解析 C API

我正在尝试解析以下 XML 文件:

<root>Root
    <pai>Pai_1
        <filho>Pai1,Filho1</filho>
        <filho>Pai1,Filho2</filho>
    </pai>
    <pai>Pai_2
        <filho>Pai2,Filho1</filho>
        <filho>Pai2,Filho2</filho>
    </pai>
</root>

我正在使用以下 C 代码:

//... open file
xml_tree = mxmlLoadFile(NULL, fp, MXML_TEXT_CALLBACK);

node = xml_tree;
printf("%s\n", mxmlGetText(node, NULL));
// here the return is: Root
// I expected: Root, OK

node = xml_tree->child;
printf("%s\n", mxmlGetText(node, NULL));
// here the return is: Root
// I expected: Pai_1, not OK

node = mxmlGetFirstChild(xml_tree);
printf("%s\n", mxmlGetText(node, NULL));
// here the return is: Root
// I expected: Pai_1, not OK

node = mxmlFindElement(xml_tree, xml_tree, "pai", NULL, NULL, MXML_DESCEND);
printf("%s\n", mxmlGetText(node, NULL));
// here the return is: Pai_1
// I expected: Pai_1, OK

node = mxmlGetNextSibling(node);
printf("%s\n", mxmlGetText(node, NULL));
// here the return is: (NULL)
// I expected: Pai_2, not OK

如何访问根的 child ？我的访问概念在哪里错误？

谢谢你。

在@RutgersMike 回复后编辑

我扩展您的 while 循环以尝试理解 minixml 的概念:

root = mxmlLoadFile(NULL,fp,MXML_TEXT_CALLBACK);
node = root;

printf("------- Root\n");
fprintf(stdout,"Element = %s\n",mxmlGetElement(node));
fprintf(stdout,"  Value = %s\n",mxmlGetText(node,0));
printf("\n");

printf("------- First child of Root\n");
node = mxmlGetFirstChild(node);
fprintf(stdout,"Element = %s\n",mxmlGetElement(node));
fprintf(stdout,"  Value = %s\n",mxmlGetText(node,0));
printf("\n");

printf("------- Sibling 1 of First child of Root\n");
node = mxmlGetNextSibling(node);
fprintf(stdout,"Element = %s\n",mxmlGetElement(node));
fprintf(stdout,"  Value = %s\n",mxmlGetText(node,0));
printf("\n");

printf("------- Sibling 2 of First child of Root\n");
node = mxmlGetNextSibling(node);
fprintf(stdout,"Element = %s\n",mxmlGetElement(node));
fprintf(stdout,"  Value = %s\n",mxmlGetText(node,0));
printf("\n");

printf("------- Sibling 3 of First child of Root\n");
node = mxmlGetNextSibling(node);
fprintf(stdout,"Element = %s\n",mxmlGetElement(node));
fprintf(stdout,"  Value = %s\n",mxmlGetText(node,0));
printf("\n");

printf("------- Sibling 4 of First child of Root\n");
node = mxmlGetNextSibling(node);
fprintf(stdout,"Element = %s\n",mxmlGetElement(node));
fprintf(stdout,"  Value = %s\n",mxmlGetText(node,0));
printf("\n");

结果是这样的:

------- Root
Element = root
  Value = Root

------- First child of Root
Element = (null)
  Value = Root

------- Sibling 1 of First child of Root
Element = (null)
  Value =

------- Sibling 2 of First child of Root
Element = pai
  Value = Pai_1

------- Sibling 3 of First child of Root
Element = (null)
  Value =

------- Sibling 4 of First child of Root
Element = pai
  Value = Pai_2

我认为这种在 child 和 parent 之间导航的概念有点奇怪。为什么 sibling 之间有(空)值？

我正在考虑回到ezxml。

谢谢

最佳答案

看起来您想使用此处描述的迭代函数 ( http://www.minixml.org/mxml.html#3_7 ) 来获取子节点。

编辑:我写这个是为了遍历第一个子节点，它工作正常，使用 mxmlGetFirstChild 和 mxmlGetNextSibling :

<!-- language: c -->
mxml_node_t* node = mxmlLoadFile(NULL,f,MXML_TEXT_CALLBACK);
while ( node != NULL )
{
   switch ( mxmlGetType(node) )
   {
   case MXML_ELEMENT:
   {
      fprintf(stdout,"Element = %s\n",mxmlGetElement(node));
   }
   break;
   case MXML_TEXT:
   {
      fprintf(stdout,"  Value = %s\n",mxmlGetText(node,0));
   }
   break;
   default:
   {
   }
   break;
   }
   mxml_node_t* next = mxmlGetFirstChild(node);
   if ( next != NULL )
   {
      node = next;
   }
   else
   {
      next = mxmlGetNextSibling(node);
      if ( next != NULL )
      {
         node = next;
      }
      else
      {
         node = next;
         fprintf(stdout,"Done\n");
      }
   }
}

产生输出:

Element = root
Value = Root
Value =
Element = pai
Value = Pai_1
Value =
Element = filho
Value = Pai1,Filho1

如果您想遍历整个文件，我认为您可以使用 getParent 函数之一来迭代备份，或者在深入到子节点之前保存最后一个节点，使用节点指针堆栈。请注意，我只处理/打印两种节点类型的数据 - 如果您还需要该信息，您将需要试验以查看其他节点类型包含的内容。

** 编辑后进行更多编辑 **

前几天我建议其他人尝试 libxml2 ( http://xmlsoft.org/examples/index.html#xmlReader ) - 检查该链接。 xmlReader 示例显示了用法。创建读取器并遍历节点非常容易 - 当您点击每个节点时，只需检查它的类型以确保它是您关心的类型(通常是 ELEMENT 、 ATTRIBUTE 、 TEXT 和 END_ELEMENT )，然后取出名称或值(value)。我比 mxml 更喜欢它。

关于c - miniXML 解析 C API，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/9806996/