我需要在父项而不是子项中插入之前或插入之后

Question

这是我的 Xml

<root>
<categories>
    <recipe id="RecipeID2">
        <name>something 1</name>
    </recipe>
    <recipe id="RecipeID2">
        <name>something 2</name>
    </recipe>
    <recipe id="RecipeID3">
        <name>something 3</name>
    </recipe>
</categories>
</root>

我正在解析客户想要在之后或之前插入新配方的所有食谱

XmlDocument xmlDocument = new XmlDocument();
xmlDocument.Load("thexmlfiles.xml");
XmlNodeList nodes = xmlDocument.SelectNodes("/root/categories//Recipe");
foreach (XmlNode node in nodes)
{
    if (node.Attributes["id"].InnerText == comboBoxInsertRecipe.Text)
    {
        node.InsertAfter(xfrag, node.ChildNodes[0]);
    }
}

预期产出：

<root>
<categories>
    <recipe id="RecipeID2">
        <name>something 1</name>
    </recipe>
    <recipe id="RecipeID2">
        <name>something 2</name>
    </recipe>
    <recipe id="NewRecipe4">
        <name>new Recipe 4</name>
    </recipe>
    <recipe id="RecipeID3">
        <name>something 3</name>
    </recipe>
</categories>
</root>

但是当我插入我的新食谱时，它确实是这样的

<root>
<categories>
    <recipe id="RecipeID2">
        <name>something 1</name>
    </recipe>
    <recipe id="RecipeID2">
        <name>something 2</name>
    </recipe>
    <recipe id="RecipeID3">
        <name>something 3</name>
        <recipe id="NewRecipe4">
            <name>new Recipe 4</name>
        </recipe>
    </recipe>
</categories>
</root>

新配方位于另一个配方中，但不在类别内

Answer 1

首先，我建议使用 LINQ-to-XML。此答案中的 L2Xml 示例。

XDocument xmlDocument = XDocument.Load("thexmlfiles.xml");
var root = xmlDocument.Root;
var recipes = root.Element("categories").Elements("recipe");

其次，获取您希望在之前/之后插入的节点的句柄/引用。

var currentRecipe = recipes.Where(r => r.Attribute("id") == "RecipeID3")
   .FirstOrDefault();

。然后根据需要添加（使用 XElement.AddAfterSelf 或 XElement.AddBeforeSelf）：

void AddNewRecipe(XElement NewRecipe, bool IsAfter, XElement CurrentRecipe) {
   if(IsAfter) {
      CurrentRecipe.AddAfterSelf(NewRecipe);
   } else {
      CurrentRecipe.AddBeforeSelf(NewRecipe);
   }
}

Answer 2

您在错误的文档级别添加新节点。必须将元素添加到（如所指向的）到类别节点，而不是添加到同级节点。有两个选项可以查找正确的节点，然后将节点添加到正确的位置：

• 当您执行此操作时，遍历所有节点以查找匹配项
• 直接使用 XPath/path/element[@attribute='attributeName'] 查找节点

将节点添加到正确位置的示例如下所示：

XmlDocument xmlDocument = new XmlDocument();
xmlDocument.Load(@"d:tempthexmlfile.xml");
XmlNodeList nodes = xmlDocument.SelectNodes("/root/categories/recipe");
// root node
XmlNodeList category = xmlDocument.SelectNodes("/root/categories");
// test node for the example
var newRecipe = xmlDocument.CreateNode(XmlNodeType.Element, "recipe", "");
var newInnerNode = xmlDocument.CreateNode(XmlNodeType.Element, "name", "");
newInnerNode.InnerText = "test";
var attribute = xmlDocument.CreateAttribute("id");
attribute.Value = "RecipeID4";
newRecipe.Attributes.Append(attribute);
newRecipe.AppendChild(newInnerNode);
// variant 1; find node while iteration over all nodes
foreach (XmlNode node in nodes)
{
    if (node.Attributes["id"].InnerText == "RecipeID3")
    {
        // insert into the root node after the found node
        category[0].InsertAfter(newRecipe, node);
    }
}
// variant 2; use XPath to select the element with the attribute directly
//category[0].InsertAfter(newRecipe, xmlDocument.SelectSingleNode("/root/categories/recipe[@id='RecipeID3']"));
// 
xmlDocument.Save(@"d:tempthexmlfileresult.xml");

输出为：

<root>
    <categories>
        <recipe id="RecipeID1">
            <name>something 1</name>
        </recipe>
        <recipe id="RecipeID2">
            <name>something 2</name>
        </recipe>
        <recipe id="RecipeID3">
            <name>something 3</name>
        </recipe>
        <recipe id="RecipeID4">
            <name>test</name>
        </recipe>
    </categories>
</root>

正如还建议的那样，您可以使用LINQ2XML做到这一点。代码可能如下所示：

// load document ...
var xml = XDocument.Load(@"d:tempthexmlfile.xml");
// find node and add new one after it
xml.Root                        // from root
    .Elements("categories")     // find categories
    .Elements("recipe")         // all recipe nodes
    .FirstOrDefault(r => r.Attribute("id").Value == "RecipeID3")    // find node by attribute
    .AddAfterSelf(new XElement("recipe",                            // create new recipe node
                    new XAttribute("id", "RecipeID4"),              // with attribute
                    new XElement("name", "test")));                 // and content - name node
// and save document ...
xml.Save(@"d:tempthexmlfileresult.xml");

输出是相同的。LINQ2XML在许多方面比 XmlDocument 更容易、更舒适地使用。例如，选择子节点可能会容易得多，并且您不需要 XPath 字符串：

xml.Descendants("recipe");

LINQ2XML值得一试。