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LINQ读取XML

如何解决《LINQ读取XML》经验,为你挑选了5个好方法。

我有这个XML文件


    
        
        
    
    
        
        
    
    

有人可以使用LINQ给我一个C#代码,这是打印此结果的最简单方法:(
如果它是一个level2节点,请注意额外的空间)

A
  A1
  A2
B
  B1
  B2
C

目前我得到了这段代码

XDocument xdoc = XDocument.Load("data.xml"));
var lv1s = from lv1 in xdoc.Descendants("level1")
           select lv1.Attribute("name").Value;

foreach (var lv1 in lv1s)
{
    result.AppendLine(lv1);

    var lv2s = from lv2 in xdoc...???
}

bendewey.. 219

试试这个.

using System.Xml.Linq;

void Main()
{
    StringBuilder result = new StringBuilder();

    //Load xml
    XDocument xdoc = XDocument.Load("data.xml");

    //Run query
    var lv1s = from lv1 in xdoc.Descendants("level1")
               select new { 
                   Header = lv1.Attribute("name").Value,
                   Children = lv1.Descendants("level2")
               };

    //Loop through results
    foreach (var lv1 in lv1s){
            result.AppendLine(lv1.Header);
            foreach(var lv2 in lv1.Children)
                 result.AppendLine("     " + lv2.Attribute("name").Value);
    }

    Console.WriteLine(result);
}

这看起来像一种"硬编码"的方法. (26认同)

@bendewey我问一个类似的问题,请你检查一下,这里:http://stackoverflow.com/questions/13247449/customize-xml-serialize-with-new-tags-and-attributes-and-root (3认同)

就像乘坐航空母舰去钓鱼一样. (2认同)


dommer.. 53

或者,如果您想要更通用的方法 - 即嵌套到"levelN":

void Main()
{
    XElement rootElement = XElement.Load(@"c:\events\test.xml");

    Console.WriteLine(GetOutline(0, rootElement));  
}

private string GetOutline(int indentLevel, XElement element)
{
    StringBuilder result = new StringBuilder();

    if (element.Attribute("name") != null)
    {
        result = result.AppendLine(new string(' ', indentLevel * 2) + element.Attribute("name").Value);
    }

    foreach (XElement childElement in element.Elements())
    {
        result.Append(GetOutline(indentLevel + 1, childElement));
    }

    return result.ToString();
}


dommer.. 21

一些简单的旧foreach循环提供了一个干净的解决方案:

foreach (XElement level1Element in XElement.Load("data.xml").Elements("level1"))
{
    result.AppendLine(level1Element.Attribute("name").Value);

    foreach (XElement level2Element in level1Element.Elements("level2"))
    {
        result.AppendLine("  " + level2Element.Attribute("name").Value);
    }
}


delliottg.. 19

以下是一些基于@bendewey和@dommer示例的完整工作示例.我需要稍微调整一下才能使它工作,但是如果另一个LINQ noob正在寻找工作示例,那么你去:

//bendewey's example using data.xml from OP
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;

class loadXMLToLINQ1
{
    static void Main( )
    {
        //Load xml
        XDocument xdoc = XDocument.Load(@"c:\\data.xml"); //you'll have to edit your path

        //Run query
        var lv1s = from lv1 in xdoc.Descendants("level1")
           select new 
           { 
               Header = lv1.Attribute("name").Value,
               Children = lv1.Descendants("level2")
            };

        StringBuilder result = new StringBuilder(); //had to add this to make the result work
        //Loop through results
        foreach (var lv1 in lv1s)
        {
            result.AppendLine("  " + lv1.Header);
            foreach(var lv2 in lv1.Children)
            result.AppendLine("    " + lv2.Attribute("name").Value);
        }
        Console.WriteLine(result.ToString()); //added this so you could see the output on the console
    }
}

接下来:

//Dommer's example, using data.xml from OP
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;

class loadXMLToLINQ
{
static void Main( )
    {
        XElement rootElement = XElement.Load(@"c:\\data.xml"); //you'll have to edit your path
        Console.WriteLine(GetOutline(0, rootElement));  
    }

static private string GetOutline(int indentLevel, XElement element)
    {
        StringBuilder result = new StringBuilder();
        if (element.Attribute("name") != null)
        {
            result = result.AppendLine(new string(' ', indentLevel * 2) + element.Attribute("name").Value);
        }
        foreach (XElement childElement in element.Elements())
        {
            result.Append(GetOutline(indentLevel + 1, childElement));
        }
        return result.ToString();
    }
}

这些都使用csc.exe版本4.0.30319.1在VS2010中编译和工作,并提供完全相同的输出.希望这些可以帮助那些正在寻找代码工作示例的人.

编辑:添加了@eglasius的例子,因为它对我有用:

//@eglasius example, still using data.xml from OP
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;

class loadXMLToLINQ2
{
    static void Main( )
    {
        StringBuilder result = new StringBuilder(); //needed for result below
        XDocument xdoc = XDocument.Load(@"c:\\deg\\data.xml"); //you'll have to edit your path
        var lv1s = xdoc.Root.Descendants("level1"); 
        var lvs = lv1s.SelectMany(l=>
             new string[]{ l.Attribute("name").Value }
             .Union(
                 l.Descendants("level2")
                 .Select(l2=>"   " + l2.Attribute("name").Value)
              )
            );
        foreach (var lv in lvs)
        {
           result.AppendLine(lv);
        }
        Console.WriteLine(result);//added this so you could see the result
    }
}


eglasius.. 8

XDocument xdoc = XDocument.Load("data.xml");
var lv1s = xdoc.Root.Descendants("level1"); 
var lvs = lv1s.SelectMany(l=>
     new string[]{ l.Attribute("name").Value }
     .Union(
         l.Descendants("level2")
         .Select(l2=>"   " + l2.Attribute("name").Value)
      )
    );
foreach (var lv in lvs)
{
   result.AppendLine(lv);
}

PS.你必须在任何这些版本上使用.Root.



1> bendewey..:

试试这个.

using System.Xml.Linq;

void Main()
{
    StringBuilder result = new StringBuilder();

    //Load xml
    XDocument xdoc = XDocument.Load("data.xml");

    //Run query
    var lv1s = from lv1 in xdoc.Descendants("level1")
               select new { 
                   Header = lv1.Attribute("name").Value,
                   Children = lv1.Descendants("level2")
               };

    //Loop through results
    foreach (var lv1 in lv1s){
            result.AppendLine(lv1.Header);
            foreach(var lv2 in lv1.Children)
                 result.AppendLine("     " + lv2.Attribute("name").Value);
    }

    Console.WriteLine(result);
}


这看起来像一种"硬编码"的方法.
@bendewey我问一个类似的问题,请你检查一下,这里:http://stackoverflow.com/questions/13247449/customize-xml-serialize-with-new-tags-and-attributes-and-root
就像乘坐航空母舰去钓鱼一样.

2> dommer..:

或者,如果您想要更通用的方法 - 即嵌套到"levelN":

void Main()
{
    XElement rootElement = XElement.Load(@"c:\events\test.xml");

    Console.WriteLine(GetOutline(0, rootElement));  
}

private string GetOutline(int indentLevel, XElement element)
{
    StringBuilder result = new StringBuilder();

    if (element.Attribute("name") != null)
    {
        result = result.AppendLine(new string(' ', indentLevel * 2) + element.Attribute("name").Value);
    }

    foreach (XElement childElement in element.Elements())
    {
        result.Append(GetOutline(indentLevel + 1, childElement));
    }

    return result.ToString();
}



3> dommer..:

一些简单的旧foreach循环提供了一个干净的解决方案:

foreach (XElement level1Element in XElement.Load("data.xml").Elements("level1"))
{
    result.AppendLine(level1Element.Attribute("name").Value);

    foreach (XElement level2Element in level1Element.Elements("level2"))
    {
        result.AppendLine("  " + level2Element.Attribute("name").Value);
    }
}



4> delliottg..:

以下是一些基于@bendewey和@dommer示例的完整工作示例.我需要稍微调整一下才能使它工作,但是如果另一个LINQ noob正在寻找工作示例,那么你去:

//bendewey's example using data.xml from OP
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;

class loadXMLToLINQ1
{
    static void Main( )
    {
        //Load xml
        XDocument xdoc = XDocument.Load(@"c:\\data.xml"); //you'll have to edit your path

        //Run query
        var lv1s = from lv1 in xdoc.Descendants("level1")
           select new 
           { 
               Header = lv1.Attribute("name").Value,
               Children = lv1.Descendants("level2")
            };

        StringBuilder result = new StringBuilder(); //had to add this to make the result work
        //Loop through results
        foreach (var lv1 in lv1s)
        {
            result.AppendLine("  " + lv1.Header);
            foreach(var lv2 in lv1.Children)
            result.AppendLine("    " + lv2.Attribute("name").Value);
        }
        Console.WriteLine(result.ToString()); //added this so you could see the output on the console
    }
}

接下来:

//Dommer's example, using data.xml from OP
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;

class loadXMLToLINQ
{
static void Main( )
    {
        XElement rootElement = XElement.Load(@"c:\\data.xml"); //you'll have to edit your path
        Console.WriteLine(GetOutline(0, rootElement));  
    }

static private string GetOutline(int indentLevel, XElement element)
    {
        StringBuilder result = new StringBuilder();
        if (element.Attribute("name") != null)
        {
            result = result.AppendLine(new string(' ', indentLevel * 2) + element.Attribute("name").Value);
        }
        foreach (XElement childElement in element.Elements())
        {
            result.Append(GetOutline(indentLevel + 1, childElement));
        }
        return result.ToString();
    }
}

这些都使用csc.exe版本4.0.30319.1在VS2010中编译和工作,并提供完全相同的输出.希望这些可以帮助那些正在寻找代码工作示例的人.

编辑:添加了@eglasius的例子,因为它对我有用:

//@eglasius example, still using data.xml from OP
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml.Linq;

class loadXMLToLINQ2
{
    static void Main( )
    {
        StringBuilder result = new StringBuilder(); //needed for result below
        XDocument xdoc = XDocument.Load(@"c:\\deg\\data.xml"); //you'll have to edit your path
        var lv1s = xdoc.Root.Descendants("level1"); 
        var lvs = lv1s.SelectMany(l=>
             new string[]{ l.Attribute("name").Value }
             .Union(
                 l.Descendants("level2")
                 .Select(l2=>"   " + l2.Attribute("name").Value)
              )
            );
        foreach (var lv in lvs)
        {
           result.AppendLine(lv);
        }
        Console.WriteLine(result);//added this so you could see the result
    }
}



5> eglasius..:
XDocument xdoc = XDocument.Load("data.xml");
var lv1s = xdoc.Root.Descendants("level1"); 
var lvs = lv1s.SelectMany(l=>
     new string[]{ l.Attribute("name").Value }
     .Union(
         l.Descendants("level2")
         .Select(l2=>"   " + l2.Attribute("name").Value)
      )
    );
foreach (var lv in lvs)
{
   result.AppendLine(lv);
}

PS.你必须在任何这些版本上使用.Root.

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