form1.vb

用vb.net写的基于c/s结构的进销存程序设计源代码

Imports System.Data.SqlClient
Public Class Form1
    Inherits System.Windows.Forms.Form
    Dim WithEvents cnNorthwind As New SqlConnection()

#Region " Windows 窗体设计器生成的代码 "

    Public Sub New()
        MyBase.New()

        '该调用是 Windows 窗体设计器所必需的。
        InitializeComponent()

        '在 InitializeComponent() 调用之后添加任何初始化

    End Sub

    '窗体重写处置以清理组件列表。
    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

    'Windows 窗体设计器所必需的
    Private components As System.ComponentModel.IContainer

    '注意：以下过程是 Windows 窗体设计器所必需的
    '可以使用 Windows 窗体设计器修改此过程。
    '不要使用代码编辑器修改它。
    Friend WithEvents bnClose As System.Windows.Forms.Button
    Friend WithEvents bnOpen As System.Windows.Forms.Button
    Friend WithEvents lbCurrrentState As System.Windows.Forms.Label
    Friend WithEvents lbOriginalState As System.Windows.Forms.Label
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.bnClose = New System.Windows.Forms.Button()
        Me.bnOpen = New System.Windows.Forms.Button()
        Me.lbCurrrentState = New System.Windows.Forms.Label()
        Me.lbOriginalState = New System.Windows.Forms.Label()
        Me.SuspendLayout()
        '
        'bnClose
        '
        Me.bnClose.Location = New System.Drawing.Point(56, 72)
        Me.bnClose.Name = "bnClose"
        Me.bnClose.Size = New System.Drawing.Size(96, 32)
        Me.bnClose.TabIndex = 0
        Me.bnClose.Text = "关闭连结"
        '
        'bnOpen
        '
        Me.bnOpen.Location = New System.Drawing.Point(56, 24)
        Me.bnOpen.Name = "bnOpen"
        Me.bnOpen.Size = New System.Drawing.Size(96, 32)
        Me.bnOpen.TabIndex = 1
        Me.bnOpen.Text = "新建连结"
        '
        'lbCurrrentState
        '
        Me.lbCurrrentState.Location = New System.Drawing.Point(56, 128)
        Me.lbCurrrentState.Name = "lbCurrrentState"
        Me.lbCurrrentState.Size = New System.Drawing.Size(96, 32)
        Me.lbCurrrentState.TabIndex = 2
        Me.lbCurrrentState.Text = "Label1"
        '
        'lbOriginalState
        '
        Me.lbOriginalState.Location = New System.Drawing.Point(56, 176)
        Me.lbOriginalState.Name = "lbOriginalState"
        Me.lbOriginalState.Size = New System.Drawing.Size(96, 32)
        Me.lbOriginalState.TabIndex = 3
        Me.lbOriginalState.Text = "Label2"
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(292, 273)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.lbOriginalState, Me.lbCurrrentState, Me.bnOpen, Me.bnClose})
        Me.Name = "Form1"
        Me.Text = "Form1"
        Me.ResumeLayout(False)

    End Sub

#End Region
    Public Sub ButtonChange()
        bnOpen.Enabled = (cnNorthwind.State = ConnectionState.Closed)
        bnClose.Enabled = (cnNorthwind.State = ConnectionState.Open)
    End Sub

    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        cnNorthwind.ConnectionString = _
            "Data Source = localhost;" & _
            "Initial Catalog = Northwind;" & _
            "Integrated Security = SSPI;"
        ButtonChange()
        lbCurrrentState.Text() = ""
        lbOriginalState.Text = ""
    End Sub
    Private Sub cnNorthwind_StateChange(ByVal sender As Object, ByVal e As System.Data.StateChangeEventArgs) Handles cnNorthwind.StateChange
        ButtonChange()
        lbCurrrentState.Text = "目前联结状态:" + e.CurrentState.ToString()
        lbOriginalState.Text = "联结状态变更前的状态:" + e.OriginalState.ToString()
    End Sub
    Private Sub bnOpen_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bnOpen.Click
        cnNorthwind.Open()
    End Sub
    Private Sub bnClose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bnClose.Click
        cnNorthwind.Close()
    End Sub


End Class