我有一个要加载的XML文件。我想在我的代码中添加一个条件以检查并确保根节点为“ TimeLog”。如果不是,则告诉用户他们选择了错误的XML文件。
在下面的代码中,r.Name仅返回一个空字符串。我希望它返回“ TimeLog”,但不会。
private void loadFromFile(object sender, EventArgs e)
{
if(File.Exists("TimeLog.xml"))
{
XmlReader r = XmlReader.Create("TimeLog.xml");
r.MoveToContent();
r.ReadStartElement();
if (r.Name == "TimeLog") //The current value or r.name is "".
{
while (r.Read())
{
if (r.NodeType == XmlNodeType.Element)
{
r.ReadToDescendant("EntryName");
String name = r.ReadInnerXml();
r.ReadToFollowing("StartDateTime");
String start = r.ReadInnerXml();
r.ReadToFollowing("EndDateTime");
String end = r.ReadInnerXml();
r.ReadToFollowing("Duration");
String dur = r.ReadInnerXml();
entries.Add(new Entry(name, start, end, dur));
}
}
}
else
{
MessageBox.Show("This is not a TimeLog XML file", "This is not a TimeLog XML file", MessageBoxButtons.OK, MessageBoxIcon.Error, MessageBoxDefaultButton.Button1);
}
r.Close();
}
}
XML文件是我的saveToFile()函数的输出,看起来像这样
<?xml version="1.0" encoding="utf-8"?>
<TimeLog>
<Entry>
<EntryName>Entry 01</EntryName>
<StartDateTime>8/21/2015 8:50:40 PM</StartDateTime>
<EndDateTime>1/1/0001 12:00:00 AM</EndDateTime>
<Duration>00:00:00</Duration>
</Entry>
<Entry>
<EntryName>Entry 02</EntryName>
<StartDateTime>8/21/2015 8:50:40 PM</StartDateTime>
<EndDateTime>1/1/0001 12:00:00 AM</EndDateTime>
<Duration>00:00:00</Duration>
</Entry>
</TimeLog>
我如何在不调用另一个.Read()函数的情况下确保根节点的名称为“ TimeLog”,并在while语句中放弃代码的顺序?
检查当前节点是否为元素,并使阅读器前进至下一个节点。
下一个节点是XmlNodeType.Whitespace
。考虑以下XML:
<TimeLog> <Entry>
也可以写成:
<TimeLog> <Entry>
[两个
XmlNodeType.Whitespace
之间有XmlNodeType.Element
。MoveToContent
将阅读器设置为根节点-TimeLog。然后ReadStartElement
读取TimeLog并移至空白。以下视图中没有空格:
<TimeLog><Entry>
顺便说一句,您可以使用ReadToFollowing
方法:using (var reader = XmlReader.Create("file.xml")) { reader.ReadToFollowing("TimeLog"); // rest of code }
if(File.Exists("TimeLog.xml"))
{
XmlReader r = XmlReader.Create("TimeLog.xml");
r.MoveToContent();
//Here check whether there exist a root element and then also check itsname.
//If this doesn't work out then put the r.Name=="TimeLog" inside While loop and then see.
if (r.IsStartElement() && string.Equals(r.Name, "TimeLog"))
{
while (r.Read())
{
if (r.NodeType == XmlNodeType.Element)
{
r.ReadToDescendant("EntryName");
String name = r.ReadInnerXml();
r.ReadToFollowing("StartDateTime");
String start = r.ReadInnerXml();
r.ReadToFollowing("EndDateTime");
String end = r.ReadInnerXml();
r.ReadToFollowing("Duration");
String dur = r.ReadInnerXml();
entries.Add(new Entry(name, start, end, dur));
}//End of inner If
}//End of While
}//End of Outer second IF
else
{
MessageBox.Show("This is not a TimeLog XML file", "This is not a TimeLog XML file", MessageBoxButtons.OK, MessageBoxIcon.Error, MessageBoxDefaultButton.Button1);
}//End of Else
r.Close();
XDocument doc = XDocument.Load("TimeLog.xml");
if (doc.Root.Name == "TimeLog")
{
// ...
}
else
{
MessageBox.Show("This is not a TimeLog XML file", "This is not a TimeLog XML file", MessageBoxButtons.OK, MessageBoxIcon.Error, MessageBoxDefaultButton.Button1);
}
if (File.Exists("TimeLog.xml"))
{
XmlReader r = XmlReader.Create("TimeLog.xml");
while (reader.Read() && reader.NodeType != XmlNodeType.Element) ;
// r is now referencing the node for the root element.
}
有效XML文档中的根node
是XML声明,可能不是您想要的。