datasets.vb

来自「wrox出版社的另一套经典的VB2005数据库编程学习书籍,收集了书中源码,郑重」· VB 代码 · 共 102 行

Option Explicit On
Option Strict On

Imports System.Data
Imports System.IO

Public Class DataSets
    Private strPath As String
    Private strFile As String
    Private strXML As String
    Private Const strIEFile As String = "\Program Files\Internet Explorer\Iexplore.exe"

    Private Sub DataSets_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
        strPath = Application.StartupPath
    End Sub

    Private Sub btnLoadNwDs_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLoadNwDs.Click
        With Me.Northwind
            strFile = strPath + "\Northwind.xml"
            If File.Exists(strFile) Then
                Try
                    .ReadXml(strFile)
                Catch exc As Exception
                    Dim strMsg As String = "Row counts: Customers = "
                    Dim intRows As Integer
                    intRows = Me.Northwind.Customers.Count
                    strMsg += intRows.ToString + ", Orders = "
                    intRows = Me.Northwind.Orders.Count
                    strMsg += intRows.ToString + ", Order_Details = "
                    intRows = Me.Northwind.Order_Details.Count
                    strMsg += intRows.ToString
                    MsgBox(exc.Message + vbCrLf + strMsg)
                End Try
                strFile = strPath + "\Output.xml"
                .WriteXml(strFile, XmlWriteMode.IgnoreSchema)
                Shell("""" + strIEFile + """ " + strFile, AppWinStyle.NormalFocus)
                btnSaveTables.Enabled = False
                btnLoadDetails.Enabled = False
                btnLoadOrders.Enabled = False
            End If
        End With
    End Sub

    Private Sub btnLoadCustomers_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLoadCustomers.Click
        With Me.Northwind
            strFile = strPath + "\TableCustomers.xml"
            If File.Exists(strFile) Then
                .Clear()
                .ReadXml(strFile)
                strFile = strPath + "\Output.xml"
                .WriteXml(strFile, XmlWriteMode.IgnoreSchema)
                Shell("""" + strIEFile + """ " + strFile, AppWinStyle.NormalFocus)
                btnLoadOrders.Enabled = True
            End If
        End With
    End Sub

    Private Sub btnLoadOrders_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLoadOrders.Click
        With Me.Northwind
            strFile = strPath + "\TableOrders.xml"
            If File.Exists(strFile) Then
                .ReadXml(strFile)
                strFile = strPath + "\Output.xml"
                .WriteXml(strFile, XmlWriteMode.IgnoreSchema)
                Shell("""" + strIEFile + """ " + strFile, AppWinStyle.NormalFocus)
                btnLoadDetails.Enabled = True
            End If
        End With
    End Sub

    Private Sub btnLoadDetails_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLoadDetails.Click
        With Me.Northwind
            strFile = strPath + "\TableDetails.xml"
            If File.Exists(strFile) Then
                .ReadXml(strFile)
                strFile = strPath + "\Output.xml"
                .WriteXml(strFile, XmlWriteMode.IgnoreSchema)
                Shell("""" + strIEFile + """ " + strFile, AppWinStyle.NormalFocus)
                btnSaveTables.Enabled = True
            End If
        End With
    End Sub

    Private Sub btnShowNwXsd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnShowNwXsd.Click
        strFile = strPath + "\Northwind.xsd"
        If File.Exists(strFile) Then
            Shell("""" + strIEFile + """ " + strFile, AppWinStyle.NormalFocus)
        End If
    End Sub

    Private Sub btnSaveTables_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSaveTables.Click
        With Me.Northwind
            strFile = strPath + "\OutputCustomers.xml"
            .Customers.WriteXml(strFile, XmlWriteMode.IgnoreSchema)
            strFile = strPath + "\OutputOrders.xml"
            .Customers.WriteXml(strFile, XmlWriteMode.IgnoreSchema)
            strFile = strPath + "\OutputDetails.xml"
            .Customers.WriteXml(strFile, XmlWriteMode.IgnoreSchema)
        End With
    End Sub
End Class