XObject.IXmlLineInfo.HasLineInfo 方法

定义

命名空间:

System.Xml.Linq

程序集:

System.Xml.XDocument.dll

程序集:

System.Xml.Linq.dll

程序集:

netstandard.dll

获取一个值，该值指示此 XObject 是否具有行信息。

 virtual bool System.Xml.IXmlLineInfo.HasLineInfo() = System::Xml::IXmlLineInfo::HasLineInfo;

bool IXmlLineInfo.HasLineInfo ();

abstract member System.Xml.IXmlLineInfo.HasLineInfo : unit -> bool
override this.System.Xml.IXmlLineInfo.HasLineInfo : unit -> bool

Function HasLineInfo () As Boolean Implements IXmlLineInfo.HasLineInfo

返回

Boolean

如果 XObject 具有行信息，则为 true；否则为 false。

实现

HasLineInfo()

示例

此示例从文件加载一个小 XML 树，设置用于设置基 URI 和保留行信息的选项。 然后，它添加另一个没有行信息的元素。 然后，它会打印树中每个元素的行信息。

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：

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

可以调用此方法来确定 XObject 是否包含有效的行信息。

此方法是接口中 IXmlLineInfo 方法的显式接口成员实现，因此为了调用此方法，必须强制转换为 IXmlLineInfo。