XObject.IXmlLineInfo.HasLineInfo 方法

定義

命名空間:

System.Xml.Linq

組件:

System.Xml.XDocument.dll

來源:

XObject.cs

取得值，指出此 XObject 是否具有行資訊。

 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

傳回

Boolean

如果 XObject 具有行資訊，則為 true；否則為 false。

實作

HasLineInfo()

範例

本範例會從檔案載入小型 XML 樹狀結構，設定選項以設定基底 URI 並保留行資訊。 然後，它會新增另一個沒有行資訊的專案。 然後，它會列印樹狀結構中每個專案的行資訊。

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  

這個範例會產生下列輸出：

BaseUri: Test.xml  

Element Name        Line Position  
------------        ---- --------  
Root                1    2  
  Child1            2    6  
  Child2            3    6  
  Child3            No Line Information  
  Child4            4    6  

備註

您可以呼叫這個方法來判斷 是否 XObject 包含有效的行資訊。

這個方法是 介面中 IXmlLineInfo 方法的明確介面成員實作，因此若要呼叫這個方法，就必須轉換成 IXmlLineInfo 。