c# – 如何获取字符串中的xml节点值

我尝试下面的代码来获取特定节点的值,但是在加载xml时抛出了这个异常：

例外：

Data at the root level is invalid. Line 1,position 1.

XML

<?xml version="1.0"?>
<Data xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"> 
    <Date>11-07-2013</Date> 
    <Start_Time>PM 01:37:11</Start_Time> 
    <End_Time>PM 01:37:14</End_Time> 
    <Total_Time>00:00:03</Total_Time> 
    <Interval_Time/>
    <Worked_Time>00:00:03</Worked_Time> 
    <Short_Fall>08:29:57</Short_Fall> 
    <Gain_Time>00:00:00</Gain_Time> 
</Data>

C#：

XmlDocument xml = new XmlDocument();
filePath = @"D:\Work_Time_Calculator\10-07-2013.xml";
xml.LoadXml(filePath);  // Exception occurs here 
XmlNode node = xml.SelectSingleNode("/Data[@*]/Short_Fall");
string id = node["Short_Fall"].InnerText;

修改后的代码

C#：

XmlDocument xml = new XmlDocument();
filePath = @"D:\Work_Time_Calculator\10-07-2013.xml";
xml.Load(filePath);  
XmlNode node = xml.SelectSingleNode("/Data[@*]/Short_Fall");
string id = node["Short_Fall"].InnerText; // Exception occurs here ("Object reference not set to an instance of an object.")

解决方法

你的代码中的问题是xml.LoadXml(filePath);

LoadXml method take parameter as xml data not the xml file path

尝试这段代码

string xmlFile = File.ReadAllText(@"D:\Work_Time_Calculator\10-07-2013.xml");
                XmlDocument xmldoc = new XmlDocument();
                xmldoc.LoadXml(xmlFile);
                XmlNodeList nodeList = xmldoc.GetElementsByTagName("Short_Fall");
                string Short_Fall=string.Empty;
                foreach (XmlNode node in nodeList)
                {
                    Short_Fall = node.InnerText;
                }

编辑

看到你的问题的最后一个编辑我找到了解决方案,

只需更换下面的2行

XmlNode node = xml.SelectSingleNode("/Data[@*]/Short_Fall");
string id = node["Short_Fall"].InnerText; // Exception occurs here ("Object reference not set to an instance of an object.")

同

string id = xml.SelectSingleNode("Data/Short_Fall").InnerText;

它应该解决你的问题,或者你可以使用我之前提供的解决方案.

原文地址：https://www.jb51.cc/csharp/92833.html