VB.NET DataSet.WriteXml方法代码示例

Private Sub WriteXmlToFile(thisDataSet As DataSet)
    If thisDataSet Is Nothing Then
        Return
    End If

    ' Create a file name to write to.
    Dim filename As String = "XmlDoc.xml"

    ' Create the FileStream to write with.
    Dim stream As New System.IO.FileStream _
       (filename, System.IO.FileMode.Create)

    ' Create an XmlTextWriter with the fileStream.
    Dim xmlWriter As New System.Xml.XmlTextWriter _
       (stream, System.Text.Encoding.Unicode)

    ' Write to the file with the WriteXml method.
    thisDataSet.WriteXml(xmlWriter)
    xmlWriter.Close()
End Sub

Private Sub WriteXmlToFile(thisDataSet As DataSet)
    If thisDataSet Is Nothing Then
        Return
    End If

    ' Create a file name to write to.
    Dim filename As String = "XmlDoc.xml"

    ' Write to the file with the WriteXml method.
    thisDataSet.WriteXml(filename)
End Sub

Private Sub DemonstrateReadWriteXMLDocumentWithFileStream()
    ' Create a DataSet with one table and two columns.
    Dim originalDataSet As New DataSet("dataSet")
    Dim table As New DataTable("table")
    Dim idColumn As New DataColumn("id", _
       Type.GetType("System.Int32"))
    idColumn.AutoIncrement = True

    Dim itemColumn As New DataColumn("item")
    table.Columns.Add(idColumn)
    table.Columns.Add(itemColumn)
    originalDataSet.Tables.Add(table)

    ' Add ten rows.
    Dim newRow As DataRow
    Dim i As Integer
    For i = 0 To 9
        newRow = table.NewRow()
        newRow("item") = "item " & i.ToString()
        table.Rows.Add(newRow)
    Next i
    originalDataSet.AcceptChanges()

    ' Print out values of each table in the DataSet 
    ' using the function defined below.
    PrintValues(originalDataSet, "Original DataSet")

    ' Write the schema and data to XML file with FileStream.
    Dim xmlFilename As String = "XmlDocument.xml"
    Dim streamWrite As New System.IO.FileStream _
       (xmlFilename, System.IO.FileMode.Create)

    ' Use WriteXml to write the XML document.
    originalDataSet.WriteXml(streamWrite)

    ' Close the FileStream.
    streamWrite.Close()
     
    ' Dispose of the original DataSet.
    originalDataSet.Dispose()
    ' Create a new DataSet.
    Dim newDataSet As New DataSet("New DataSet")
       
    ' Read the XML document back in. 
    ' Create new FileStream to read schema with.
    Dim streamRead As New System.IO.FileStream _
       (xmlFilename, System.IO.FileMode.Open)
     
    newDataSet.ReadXml(streamRead)
    ' Print out values of each table in the DataSet  
    ' using the function defined below.
    PrintValues(newDataSet, "New DataSet")
End Sub
   
Private Sub PrintValues(dataSet As DataSet, label As String)
    Console.WriteLine(ControlChars.Cr & label)
    Dim table As DataTable
    Dim row As DataRow
    Dim column As DataColumn
    For Each table In  dataSet.Tables
        Console.WriteLine("TableName: " & table.TableName)         
        For Each row In  table.Rows             
            For Each column In  table.Columns
                Console.Write(ControlChars.Tab & " " & _
                   row(column).ToString())
            Next column
            Console.WriteLine()
        Next row
    Next table
End Sub

Private Sub WriteXmlToFile(thisDataSet As DataSet)
     If thisDataSet Is Nothing Then
         Return
     End If 

    ' Create a file name to write to.
     Dim filename As String = "XmlDoc.xml"

     ' Create the FileStream to write with.
     Dim stream As New System.IO.FileStream _
        (filename, System.IO.FileMode.Create)

     ' Write to the file with the WriteXml method.
     thisDataSet.WriteXml(stream)
End Sub