Question

我正在编写一个从给定路径读取XML文件的Sub，然后将其加载到对象数组中。出于某种原因，该算法适用于名称，但拒绝使用成本和类型标记。发生了什么事？

（更新： 拒绝工作表示它返回一个空字符串，或者在成本为0的情况下）

这是我的代码：

Public Sub New(ByVal Path As String)
    Try
        Dim XML As New XmlTextReader(Path)
        Try
            Dim Bool As Boolean = False
            Dim Name As String = ""
            Dim Cost As Double = 0
            Dim Type As String = ""
            While True
                XML.Read()
                If Bool Then
                    Select Case XML.Name
                        Case Is = "name"
                            XML.Read()
                            Name = XML.Value
                        Case Is = "cost"
                            XML.Read()
                            Double.TryParse(XML.Value, Cost)
                        Case Is = "type"
                            XML.Read()
                            Type = XML.Value
                    End Select
                End If
                If XML.Name = "card" Then
                    Bool = True
                End If
                If Not CheckNulls(Name, Cost, Type) Then //CheckNulls returns true if all arguments passed to it are either empty strings, or 0
                    Dim Card As New Card(Name, Cost, Type)
                    Deck.Add(Card)
                    Cost = 0
                    Name = ""
                    Type = ""
                    Bool = False
                End If
            End While
        Catch Ex As Exception
            Exit Sub
        End Try
    Catch Ex As Exception
        MsgBox("The System has encountered an error. Running the software anymore could cause a serious malfunction. Please exit now", MsgBoxStyle.OkOnly, "Error Message")
    End Try
End Sub

这是XML文件：蒙娜丽莎 2000 艺术波尔卡圆点 35.85 艺术

Answer 1

以您的方式阅读XML数据既笨拙又容易出错。最好使用XPath Expressions从XML文件中提取您感兴趣的数据，只需一行代码即可获取数据。

您可以在此处详细了解XPath Expressions语法，以便开始使用

http://www.w3schools.com/xsl/xpath_syntax.asp

要了解如何在VB.NET代码中使用Xpath表达式，您可能会在互联网上找到很多有趣的文章。其中一个以易于理解的语言解释它是：

http://www.aspsnippets.com/Articles/XmlDocument-XPath-Example-Select-XML-nodes-by-Name-and-Attribute-values-in-C-and-VBNet.aspx

XML Reading Sub不工作

1 个答案: