假设xml文件内容是
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- <?xml version="1.0" encoding="utf-8"?>
- <Workflow>
- <Activity>
- <ActivityId>1</ActivityId>
- <ActivityName>start</ActivityName>
- <BindingPageId>1</BindingPageId>
- <BindingRoleId>1</BindingRoleId>
- <ActivityLevel>1</ActivityLevel>
- </Activity>
- <Activity>
- <ActivityId>2</ActivityId>
- <ActivityName>pass</ActivityName>
- <BindingPageId>2</BindingPageId>
- <BindingRoleId>2</BindingRoleId>
- <ActivityLevel>2</ActivityLevel>
- </Activity>
- </Workflow>
<?xml version="1.0" encoding="utf-8"?>
<Workflow>
<Activity>
<ActivityId>1</ActivityId>
<ActivityName>start</ActivityName>
<BindingPageId>1</BindingPageId>
<BindingRoleId>1</BindingRoleId>
<ActivityLevel>1</ActivityLevel>
</Activity>
<Activity>
<ActivityId>2</ActivityId>
<ActivityName>pass</ActivityName>
<BindingPageId>2</BindingPageId>
<BindingRoleId>2</BindingRoleId>
<ActivityLevel>2</ActivityLevel>
</Activity>
</Workflow>
我们需要读取Activity节点下的内容,因为存在多个Activity,所以需要读取多个节点。可以使用 XmlDocument.SelectSingleNode和XmlDocument.SelectNodes方法查找节点。前一个是查找匹配的第一个节点,而后一个则会返回一个节点列表。
1.XmlDocument.SelectSingleNode方法的使用
首先创建一个读取xml文件的方法ReadXmlNode
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- /// <summary>
- /// 读取xml中的指定节点的值
- /// </summary>
- public void ReadXmlNode(string filename)
- {
- XmlDocument xmlDoc = new XmlDocument();
- try
- {
- xmlDoc.Load(filename);
- //读取Activity节点下的数据。SelectSingleNode匹配第一个Activity节点
- XmlNode root = xmlDoc.SelectSingleNode("//Activity");//当节点Workflow带有属性是,使用SelectSingleNode无法读取
- if (root != null)
- {
- string ActivityId = (root.SelectSingleNode("ActivityId")).InnerText;
- string ActivityName = (root.SelectSingleNode("ActivityName ")).InnerText;
- string ActivityLevel = root.SelectSingleNode("ActivityLevel").InnerText;
- Console.WriteLine("ActivityId:" + ActivityId + "/nActivityName:" + ActivityName + "/nActivityLevel:" + ActivityLevel);
- }
- else
- {
- Console.WriteLine("the node is not existed");
- //Console.Read();
- }
- }
- catch (Exception e)
- {
- //显示错误信息
- Console.WriteLine(e.Message);
- }
- }
/// <summary>
/// 读取xml中的指定节点的值
/// </summary>
public void ReadXmlNode(string filename)
{
XmlDocument xmlDoc = new XmlDocument();
try
{
xmlDoc.Load(filename);
//读取Activity节点下的数据。SelectSingleNode匹配第一个Activity节点
XmlNode root = xmlDoc.SelectSingleNode("//Activity");//当节点Workflow带有属性是,使用SelectSingleNode无法读取
if (root != null)
{
string ActivityId = (root.SelectSingleNode("ActivityId")).InnerText;
string ActivityName = (root.SelectSingleNode("ActivityName ")).InnerText;
string ActivityLevel = root.SelectSingleNode("ActivityLevel").InnerText;
Console.WriteLine("ActivityId:" + ActivityId + "/nActivityName:" + ActivityName + "/nActivityLevel:" + ActivityLevel);
}
else
{
Console.WriteLine("the node is not existed");
//Console.Read();
}
}
catch (Exception e)
{
//显示错误信息
Console.WriteLine(e.Message);
}
}
然后在主函数中调用该方法
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- class Program
- {
- static void Main(string[] args)
- {
- XMLOperation xmlOpr = new XMLOperation();
- xmlOpr.ReadXmlNode("activity.xml");
- Console.Read();
- }
- }
class Program
{
static void Main(string[] args)
{
XMLOperation xmlOpr = new XMLOperation();
xmlOpr.ReadXmlNode("activity.xml");
Console.Read();
}
}
输出结果为:
ActivityId:1 ActivityName:start ActivityLevel:1
2.XmlDocument.SelectNodes方法的使用
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- /// <summary>
- /// 读取xml中的指定节点的值,如果有多个同名节点,则全部读取
- /// </summary>
- public void ReadXmlNodes(string filename)
- {
- XmlDocument xmlDoc = new XmlDocument();
- try
- {
- xmlDoc.Load(filename);
- XmlNodeList xnList = xmlDoc.SelectNodes("//Activity");
- Console.WriteLine("共有{0}个节点", xnList.Count);//输出xnList中节点个数。
- foreach (XmlNode xn in xnList)
- {
- //无法使用xn["ActivityId"].InnerText
- string ActivityId = (xn.SelectSingleNode("ActivityId")).InnerText;
- string ActivityName = xn.SelectSingleNode("ActivityName").InnerText;
- string ActivityLevel = xn.SelectSingleNode("ActivityLevel").InnerText;
- // Console.WriteLine("ActivityId:" + ActivityId + "/nActivityName:" + ActivityName + "/nActivityLevel:" + ActivityLevel);
- Console.WriteLine("ActivityId: {0}/nActivityName: {1}/nActivityLevel: {2}", ActivityId, ActivityName, ActivityLevel);
- }
- }
- catch (Exception e)
- {
- //显示错误信息
- Console.WriteLine(e.Message);
- }
- }
/// <summary>
/// 读取xml中的指定节点的值,如果有多个同名节点,则全部读取
/// </summary>
public void ReadXmlNodes(string filename)
{
XmlDocument xmlDoc = new XmlDocument();
try
{
xmlDoc.Load(filename);
XmlNodeList xnList = xmlDoc.SelectNodes("//Activity");
Console.WriteLine("共有{0}个节点", xnList.Count);//输出xnList中节点个数。
foreach (XmlNode xn in xnList)
{
//无法使用xn["ActivityId"].InnerText
string ActivityId = (xn.SelectSingleNode("ActivityId")).InnerText;
string ActivityName = xn.SelectSingleNode("ActivityName").InnerText;
string ActivityLevel = xn.SelectSingleNode("ActivityLevel").InnerText;
// Console.WriteLine("ActivityId:" + ActivityId + "/nActivityName:" + ActivityName + "/nActivityLevel:" + ActivityLevel);
Console.WriteLine("ActivityId: {0}/nActivityName: {1}/nActivityLevel: {2}", ActivityId, ActivityName, ActivityLevel);
}
}
catch (Exception e)
{
//显示错误信息
Console.WriteLine(e.Message);
}
}
然后在主函数中调用该方法
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- class Program
- {
- static void Main(string[] args)
- {
- XMLOperation xmlOpr = new XMLOperation();
- xmlOpr.ReadXmlNodes("activity.xml");
- Console.Read();
- }
- }
class Program
{
static void Main(string[] args)
{
XMLOperation xmlOpr = new XMLOperation();
xmlOpr.ReadXmlNodes("activity.xml");
Console.Read();
}
}
输出结果为:
共有2个节点 ActivityId: 1 ActivityName: start ActivityLevel: 1 ActivityId: 2 ActivityName: pass ActivityLevel: 2
3.通过节点属性查找指定节点
参考http://www.csharp-examples.net/xml-nodes-by-attribute-value/,虽然没有用到参考文章中的方法,不过总觉得以后会用到的。
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- /// <summary>
- ///通过ActivityLevel获取xmlnode,需要保证ActivityLevel在一个xml文档中是唯一的。
- /// </summary>
- public XmlNode getXmlNode(string filename, string activitylevel)
- {
- XmlDocument xmlDoc = new XmlDocument();
- try
- {
- xmlDoc.Load(filename);
- XmlNodeList xnList = xmlDoc.SelectNodes("//Activity");//当节点Workflow带有属性是,使用SelectSingleNode无法读取
- foreach (XmlNode xn in xnList)
- {
- string ActivityLevel = xn.SelectSingleNode("ActivityLevel").InnerText;
- if(activitylevel==ActivityLevel)
- {
- return xn;
- }
- }
- }
- catch (Exception e)
- {
- //显示错误信息
- Console.WriteLine(e.Message);
- }
- return null;
- }
/// <summary>
///通过ActivityLevel获取xmlnode,需要保证ActivityLevel在一个xml文档中是唯一的。
/// </summary>
public XmlNode getXmlNode(string filename, string activitylevel)
{
XmlDocument xmlDoc = new XmlDocument();
try
{
xmlDoc.Load(filename);
XmlNodeList xnList = xmlDoc.SelectNodes("//Activity");//当节点Workflow带有属性是,使用SelectSingleNode无法读取
foreach (XmlNode xn in xnList)
{
string ActivityLevel = xn.SelectSingleNode("ActivityLevel").InnerText;
if(activitylevel==ActivityLevel)
{
return xn;
}
}
}
catch (Exception e)
{
//显示错误信息
Console.WriteLine(e.Message);
}
return null;
}
然后在主函数中调用该方法
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- class Program
- {
- static void Main(string[] args)
- {
- XMLOperation xmlOpr = new XMLOperation();
- XmlNode xn=xmlOpr.getXmlNode("activity.xml", "2");
- string ActivityId = (xn.SelectSingleNode("ActivityId")).InnerText;
- string ActivityName = (xn.SelectSingleNode("ActivityName ")).InnerText;
- string ActivityLevel = xn.SelectSingleNode("ActivityLevel").InnerText;
- Console.WriteLine("ActivityId:" + ActivityId + "/nActivityName:" + ActivityName + "/nActivityLevel:" + ActivityLevel);
- Console.Read();
- }
- }
class Program
{
static void Main(string[] args)
{
XMLOperation xmlOpr = new XMLOperation();
XmlNode xn=xmlOpr.getXmlNode("activity.xml", "2");
string ActivityId = (xn.SelectSingleNode("ActivityId")).InnerText;
string ActivityName = (xn.SelectSingleNode("ActivityName ")).InnerText;
string ActivityLevel = xn.SelectSingleNode("ActivityLevel").InnerText;
Console.WriteLine("ActivityId:" + ActivityId + "/nActivityName:" + ActivityName + "/nActivityLevel:" + ActivityLevel);
Console.Read();
}
}
输出结果为:
ActivityId:2 ActivityName:pass ActivityLevel:2