Question

我正在尝试在VB 2008项目中创建一个树视图，该项目显示XML Schema的所有元素和属性。

XML模式的MSDN文档似乎暗示通过将模式加载到XMLSchemaSet并对其进行编译，我应该使用它们的值访问所有元素和属性，但这似乎在实践中不起作用。

使用for循环，例如：

For Each elem As XmlSchemaElement In compiledSchema.Elements.Values

我可以使用elem.Name来获取简单类型的元素名称（以及具有类似嵌套循环的属性名称），但这不适用于复杂类型。

每当（但是）我试图获得复杂类型的值时，我就会碰壁砖。

例如，下面的模式只返回“bookstore”元素。

<?xml version="1.0" encoding="utf-8"?>
<xs:schema attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.contoso.com/books" xmlns:xs="http://www.w3.org/2001/XMLSchema">
    <xs:element name="bookstore">
        <xs:complexType>
            <xs:sequence>
                <xs:element maxOccurs="unbounded" name="book">
                    <xs:complexType>
                        <xs:sequence>
                            <xs:element name="title" type="xs:string" />
                            <xs:element name="author">
                                <xs:complexType>
                                    <xs:sequence>
                                        <xs:element minOccurs="0" name="name" type="xs:string" />
                                        <xs:element minOccurs="0" name="first-name" type="xs:string" />
                                        <xs:element minOccurs="0" name="last-name" type="xs:string" />
                                    </xs:sequence>
                                </xs:complexType>
                            </xs:element>
                            <xs:element name="price" type="xs:decimal" />
                        </xs:sequence>
                        <xs:attribute name="genre" type="xs:string" use="required" />
                        <xs:attribute name="publicationdate" type="xs:unsignedShort" use="required" />
                        <xs:attribute name="ISBN" type="xs:string" use="required" />
                    </xs:complexType>
                </xs:element>
            </xs:sequence>
        </xs:complexType>
    </xs:element>
</xs:schema>

是否有任何方法可以填充树视图控件，以便显示：

bookstore
  book
    genre
    publication date
    isbn
    title
    author
      first-name
      last-name
    price

Answer 1

'DisplayXmlFile - loading a XML file in a TreeView
' Display a XML file in a TreeView
' Note: requires Imports System.Xml
' Example: DisplayXmlFile("c:\employees.xml", TreeView1)

Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
    Try
        'Dim file_name As String = ("c:\employees.xml")

        TreeView1.Nodes.Clear()

        DisplayXmlFile("c:\satellites.xml", TreeView1)
    Catch ex As Exception

    End Try
End Sub

' Display a XML file in a TreeView
' Note: requires Imports System.Xml
' Example: DisplayXmlFile("employees.xml", TreeView1)

Sub DisplayXmlFile(ByVal filename As String, ByVal tvw As TreeView)
    Dim xmldoc As New XmlDocument()
    xmldoc.Load(filename)
    ' Add it to the TreeView Nodes collection
    DisplayXmlNode(xmldoc, tvw.Nodes)
    ' Expand the root node.
    tvw.Nodes(0).Expand()
End Sub

Sub DisplayXmlNode(ByVal xmlnode As XmlNode, ByVal nodes As TreeNodeCollection)
    ' Add a TreeView node for this XmlNode.
    ' (Using the node's Name is OK for most XmlNode types.)
    Dim tvNode As TreeNode = nodes.Add(xmlnode.Name)

    Select Case xmlnode.NodeType
        Case XmlNodeType.Element
            ' This is an element: Check whether there are attributes.
            If xmlnode.Attributes.Count > 0 Then
                ' Create an ATTRIBUTES node.
                Dim attrNode As TreeNode = tvNode.Nodes.Add("(ATTRIBUTES)")
                ' Add all the attributes as children of the new node.
                Dim xmlAttr As XmlAttribute
                For Each xmlAttr In xmlnode.Attributes
                    ' Each node shows name and value.
                    attrNode.Nodes.Add(xmlAttr.Name & " = '" & xmlAttr.Value & _
                        "'")
                Next
            End If
        Case XmlNodeType.Text, XmlNodeType.CDATA
            ' For these node types we display the value
            tvNode.Text = xmlnode.Value
        Case XmlNodeType.Comment
            tvNode.Text = "<!--" & xmlnode.Value & "-->"
        Case XmlNodeType.ProcessingInstruction, XmlNodeType.XmlDeclaration
            tvNode.Text = "<?" & xmlnode.Name & " " & xmlnode.Value & "?>"
        Case Else
            ' ignore other node types.
    End Select

    ' Call this routine recursively for each child node.
    Dim xmlChild As XmlNode = xmlnode.FirstChild
    Do Until xmlChild Is Nothing
        DisplayXmlNode(xmlChild, tvNode.Nodes)
        xmlChild = xmlChild.NextSibling
    Loop
End Sub

在VB 2008中使用XSD元素和属性填充树视图

1 个答案: