backupform2.vb

是一个用SQL和VB.NET来做的源码。

Imports System
Imports System.ComponentModel
Imports System.Data
Imports System.Drawing
Imports System.Globalization
Imports System.Windows.Forms

Public Class BackupForm2
    Inherits Form

    Private components As Container
    Private button1 As Button
    Private button2 As Button
    Private button3 As Button
    Private button4 As Button
    Private text1 As TextBox
    Private text2 As TextBox
    Private text3 As TextBox

    Private bmCustomers As BindingManagerBase
    Private bmOrders As BindingManagerBase
    Private ds As DataSet
    Private DateTimePicker1 As DateTimePicker

    Public Sub New()
        ' Required for Windows Form Designer support.
        InitializeComponent()
        ' Call SetUp to bind the controls.
        SetUp()
    End Sub

    Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
        If disposing Then
            If Not (components Is Nothing) Then
                components.Dispose()
            End If
        End If
        MyBase.Dispose(disposing)
    End Sub


    Private Sub InitializeComponent()
        ' Create the form and its controls.
        With Me
            .components = New Container()
            .button1 = New Button()
            .button2 = New Button()
            .button3 = New Button()
            .button4 = New Button()
            .text1 = New TextBox()
            .text2 = New TextBox()
            .text3 = New TextBox()

            .DateTimePicker1 = New DateTimePicker()

            .AutoScaleBaseSize = New Size(5, 13)
            .Text = "Binding Sample"
            .ClientSize = New Size(450, 200)

            With .button1
                .Location = New Point(24, 16)
                .Size = New Size(64, 24)
                .Text = "<"
                AddHandler button1.Click, AddressOf button1_Click
            End With


            With .button2
                .Location = New Point(90, 16)
                .Size = New Size(64, 24)
                .Text = ">"
                AddHandler button2.Click, AddressOf button2_Click
            End With

            With .button3
                .Location = New Point(90, 100)
                .Size = New Size(64, 24)
                .Text = ">"
                AddHandler button3.Click, AddressOf button3_Click
            End With

            With .button4
                .Location = New Point(150, 100)
                .Size = New Size(64, 24)
                .Text = ">"
                AddHandler button4.Click, AddressOf button4_Click
            End With

            With .text1
                .Location = New Point(24, 50)
                .Size = New Size(150, 24)
            End With

            With .text2
                .Location = New Point(190, 50)
                .Size = New Size(150, 24)
            End With

            With .text3
                .Location = New Point(290, 150)
                .Size = New Size(150, 24)
            End With

            With .DateTimePicker1
                .Location = New Point(90, 150)
                .Size = New Size(200, 800)
            End With

            With .Controls
                .Add(button1)
                .Add(button2)
                .Add(button3)
                .Add(button4)
                .Add(text1)
                .Add(text2)
                .Add(text3)
                .Add(DateTimePicker1)
            End With
        End With
    End Sub

    Public Shared Sub Main()
        Application.Run(New BackupForm2())
    End Sub

    Private Sub SetUp()
        ' Create a DataSet with two tables and one relation.
        MakeDataSet()
        BindControls()
    End Sub

    Private Sub BindControls()
        ' Create two Binding objects for the first two TextBox
        ' controls. The data-bound property for both controls
        ' is the Text property.  The data source is a DataSet
        ' (ds). The data member is the 
        ' TableName.ColumnName" string.

        text1.DataBindings.Add(New _
           Binding("Text", ds, "customers.custName"))
        text2.DataBindings.Add(New _
           Binding("Text", ds, "customers.custID"))
        ' Bind the DateTimePicker control by adding a new Binding.
        ' The data member of the DateTimePicker is a
        ' TableName.RelationName.ColumnName string
        DateTimePicker1.DataBindings.Add(New _
           Binding("Value", ds, "customers.CustToOrders.OrderDate"))
        ' Add event delegates for the Parse and Format events to a
        ' new Binding object, and add the object to the third
        ' TextBox control's BindingsCollection. The delegates
        ' must be added before adding the Binding to the
        ' collection; otherwise, no formatting occurs until
        ' the Current object of the BindingManagerBase for
        ' the data source changes.
        Dim b As Binding = New _
           Binding("Text", ds, "customers.custToOrders.OrderAmount")
        AddHandler b.Parse, AddressOf CurrencyStringToDecimal
        AddHandler b.Format, AddressOf DecimalToCurrencyString
        text3.DataBindings.Add(b)

        ' Get the BindingManagerBase for the Customers table.
        bmCustomers = Me.BindingContext(ds, "Customers")

        ' Get the BindingManagerBase for the Orders table using the
        ' RelationName.
        bmOrders = Me.BindingContext(ds, "customers.CustToOrders")
    End Sub

    Private Sub DecimalToCurrencyString(ByVal sender As Object, ByVal cevent As ConvertEventArgs)
        ' This method is the Format event handler. Whenever the 
        ' control displays a new value, the value is converted from 
        ' its native Decimal type to a string. The ToString method 
        ' then formats the value as a Currency, by using the 
        ' formatting character "c".

        ' The application can only convert to string type. 

        If Not cevent.DesiredType Is GetType(String) Then
            Exit Sub
        End If

        cevent.Value = CType(cevent.Value, Decimal).ToString("c")
    End Sub

    Private Sub CurrencyStringToDecimal(ByVal sender As Object, ByVal cevent As ConvertEventArgs)
        ' This method is the Parse event handler. The Parse event 
        ' occurs whenever the displayed value changes. The static 
        ' ToDecimal method of the Convert class converts the 
        ' value back to its native Decimal type.

        ' Can only convert to decimal type.
        If Not cevent.DesiredType Is GetType(Decimal) Then
            Exit Sub
        End If

        cevent.Value = Decimal.Parse(cevent.Value.ToString, _
        NumberStyles.Currency, Nothing)

        ' To see that no precision is lost, print the unformatted 
        ' value. For example, changing a value to "10.0001" 
        ' causes the control to display "10.00", but the 
        ' unformatted value remains "10.0001".
        Console.WriteLine(cevent.Value)
    End Sub

    Protected Sub button1_Click(ByVal sender As Object, ByVal e As System.EventArgs)
        ' Go to the previous item in the Customer list.
        bmCustomers.Position -= 1
    End Sub

    Protected Sub button2_Click(ByVal sender As Object, ByVal e As System.EventArgs)
        ' Go to the next item in the Customer list.
        bmCustomers.Position += 1
    End Sub

    Protected Sub button3_Click(ByVal sender As Object, ByVal e As System.EventArgs)
        ' Go to the previous item in the Order list.
        bmOrders.Position -= 1
    End Sub

    Protected Sub button4_Click(ByVal sender As Object, ByVal e As System.EventArgs)
        ' Go to the next item in the Orders list.
        bmOrders.Position += 1
    End Sub

    ' Creates a DataSet with two tables and populates it.
    Private Sub MakeDataSet()
        ' Create a DataSet.
        ds = New DataSet("myDataSet")

        ' Creates two DataTables.
        Dim tCust As DataTable = New DataTable("Customers")
        Dim tOrders As DataTable = New DataTable("Orders")

        ' Create two columns, and add them to the first table.
        Dim cCustID As DataColumn = New DataColumn("CustID", _
        System.Type.GetType("System.Int32"))
        Dim cCustName As DataColumn = New DataColumn("CustName")
        tCust.Columns.Add(cCustID)
        tCust.Columns.Add(cCustName)

        ' Create three columns, and add them to the second table.
        Dim cID As DataColumn = _
           New DataColumn("CustID", System.Type.GetType("System.Int32"))
        Dim cOrderDate As DataColumn = _
           New DataColumn("orderDate", System.Type.GetType("System.DateTime"))
        Dim cOrderAmount As DataColumn = _
           New DataColumn("OrderAmount", System.Type.GetType("System.Decimal"))
        tOrders.Columns.Add(cOrderAmount)
        tOrders.Columns.Add(cID)
        tOrders.Columns.Add(cOrderDate)

        ' Add the tables to the DataSet.
        ds.Tables.Add(tCust)
        ds.Tables.Add(tOrders)

        ' Create a DataRelation, and add it to the DataSet.
        Dim dr As DataRelation = New _
           DataRelation("custToOrders", cCustID, cID)
        ds.Relations.Add(dr)

        ' Populate the tables. For each customer and orders,
        ' create two DataRow variables.
        Dim newRow1 As DataRow
        Dim newRow2 As DataRow

        ' Create three customers in the Customers Table.
        Dim i As Integer
        For i = 1 To 3
            newRow1 = tCust.NewRow
            newRow1("custID") = i
            ' Adds the row to the Customers table.
            tCust.Rows.Add(newRow1)
        Next

        ' Give each customer a distinct name.
        tCust.Rows(0)("custName") = "Alpha"
        tCust.Rows(1)("custName") = "Beta"
        tCust.Rows(2)("custName") = "Omega"

        ' For each customer, create five rows in the Orders table.
        Dim j As Integer
        For i = 1 To 3
            For j = 1 To 5
                newRow2 = tOrders.NewRow
                newRow2("CustID") = i
                newRow2("orderDate") = New DateTime(2001, i, j * 2)
                newRow2("OrderAmount") = i * 10 + j * 0.1
                ' Add the row to the Orders table.
                tOrders.Rows.Add(newRow2)
            Next
        Next
    End Sub
End Class