XObject.IXmlLineInfo.HasLineInfo 方法

定义

获取一个值,该值指示此 XObject 是否具有行信息。Gets a value indicating whether or not this XObject has line information.

 virtual bool System.Xml.IXmlLineInfo.HasLineInfo() = System::Xml::IXmlLineInfo::HasLineInfo;
bool IXmlLineInfo.HasLineInfo ();
Function HasLineInfo () As Boolean Implements IXmlLineInfo.HasLineInfo

返回

如果 true 具有行信息,则为 XObject;否则为 falsetrue if the XObject has line information; otherwise, false.

实现

示例

此示例从文件中加载一个小型 XML 树,并将选项设置为设置基 URI 和保留行信息。This example loads a small XML tree from a file, setting the options to set base URI and retain line information. 然后,它添加另一个不包含行信息的元素。It then adds another element that does not have line information. 然后打印树中每个元素的行信息。It then prints the line information for each element in the tree.

string markup = @"<Root>  
    <Child1 />  
    <Child2 />  
    <Child4 />  
</Root>";  
  
File.WriteAllText("Test.xml", markup);  
  
XElement po = XElement.Load("Test.xml",  
    LoadOptions.SetBaseUri | LoadOptions.SetLineInfo);  
  
// add a node to the tree.  
// the newly added node will not have line information.  
po.Element("Child2").AddAfterSelf(new XElement("Child3"));  
  
string[] splitUri = po.BaseUri.Split('/');  
Console.WriteLine("BaseUri: {0}", splitUri[splitUri.Length - 1]);  
Console.WriteLine();  
Console.WriteLine("{0}{1}{2}",  
    "Element Name".PadRight(20),  
    "Line".PadRight(5),  
    "Position");  
Console.WriteLine("{0}{1}{2}",  
    "------------".PadRight(20),  
    "----".PadRight(5),  
    "--------");  
foreach (XElement e in po.DescendantsAndSelf())  
    Console.WriteLine("{0}{1}{2}",  
        ("".PadRight(e.Ancestors().Count() * 2) + e.Name).PadRight(20),  
        ((IXmlLineInfo)e).HasLineInfo() ?  
            ((IXmlLineInfo)e).LineNumber.ToString().PadRight(5) :  
            "",  
        ((IXmlLineInfo)e).HasLineInfo() ?  
            ((IXmlLineInfo)e).LinePosition.ToString() :  
            "No Line Information");  
Dim markup As String = _  
    "<Root>" & Environment.NewLine & _  
    "    <Child1 />" & Environment.NewLine & _  
    "    <Child2 />" & Environment.NewLine & _  
    "    <Child4 />" & Environment.NewLine & _  
    "</Root>"  
  
File.WriteAllText("Test.xml", markup)  
  
Dim po As XElement = XElement.Load("Test.xml", LoadOptions.SetBaseUri Or LoadOptions.SetLineInfo)  
  
' add a node to the tree.  
' the newly added node will not have line information.  
po.Element("Child2").AddAfterSelf(New XElement("Child3"))  
  
Dim splitUri() As String = po.BaseUri.Split("/"c)  
Console.WriteLine("BaseUri: {0}", splitUri(splitUri.Length - 1))  
Console.WriteLine()  
Console.WriteLine("{0}{1}{2}", _  
    "Element Name".PadRight(20), _  
    "Line".PadRight(5), _  
    "Position")  
Console.WriteLine("{0}{1}{2}", _  
    "------------".PadRight(20), _  
    "----".PadRight(5), _  
    "--------")  
For Each e As XElement In po.DescendantsAndSelf()  
    Console.WriteLine("{0}{1}{2}", _  
        ("".PadRight(e.Ancestors().Count() * 2) & e.Name.ToString).PadRight(20), _  
        IIf(DirectCast(e, IXmlLineInfo).HasLineInfo(), _  
            DirectCast(e, IXmlLineInfo).LineNumber.ToString().PadRight(5), _  
            ""), _  
        IIf(DirectCast(e, IXmlLineInfo).HasLineInfo(), _  
            DirectCast(e, IXmlLineInfo).LinePosition.ToString(), _  
            "No Line Information"))  
Next  

该示例产生下面的输出:This example produces the following output:

BaseUri: Test.xml  
  
Element Name        Line Position  
------------        ---- --------  
Root                1    2  
  Child1            2    6  
  Child2            3    6  
  Child3            No Line Information  
  Child4            4    6  

注解

您可以调用此方法来确定 XObject 是否包含有效的行信息。You can call this method to determine whether the XObject contains valid line information.

此方法是 IXmlLineInfo 接口中的方法的显式接口成员实现,因此为了调用此方法,需要将转换为 IXmlLineInfoThis method is an explicit interface member implementation of a method in the IXmlLineInfo interface, so in order to call this method, it is necessary to cast to IXmlLineInfo.

适用于