frmlogin.vb

一个实际的商业项目

Imports System.Data.OleDb
Public Class frmLogin
    Inherits System.Windows.Forms.Form

    Dim WithEvents cnData As New OleDbConnection

    Public strUserPower As String
    Public strUserName As String


    Dim daUser As New OleDbCommand
    Dim daPower As New OleDbCommand
    Dim rd As OleDbDataReader

#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 dispose 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 Label1 As System.Windows.Forms.Label
    Friend WithEvents Label2 As System.Windows.Forms.Label
    Friend WithEvents cbUser As System.Windows.Forms.ComboBox
    Friend WithEvents btnOK As System.Windows.Forms.Button
    Friend WithEvents txtPassWord As System.Windows.Forms.TextBox
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.btnOK = New System.Windows.Forms.Button
        Me.Label1 = New System.Windows.Forms.Label
        Me.Label2 = New System.Windows.Forms.Label
        Me.txtPassWord = New System.Windows.Forms.TextBox
        Me.cbUser = New System.Windows.Forms.ComboBox
        Me.SuspendLayout()
        '
        'btnOK
        '
        Me.btnOK.Location = New System.Drawing.Point(232, 40)
        Me.btnOK.Name = "btnOK"
        Me.btnOK.Size = New System.Drawing.Size(75, 40)
        Me.btnOK.TabIndex = 0
        Me.btnOK.Text = "登录"
        '
        'Label1
        '
        Me.Label1.Location = New System.Drawing.Point(32, 32)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(48, 23)
        Me.Label1.TabIndex = 1
        Me.Label1.Text = "用户："
        '
        'Label2
        '
        Me.Label2.Location = New System.Drawing.Point(32, 64)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(48, 23)
        Me.Label2.TabIndex = 2
        Me.Label2.Text = "口令："
        '
        'txtPassWord
        '
        Me.txtPassWord.Location = New System.Drawing.Point(88, 64)
        Me.txtPassWord.Name = "txtPassWord"
        Me.txtPassWord.PasswordChar = Microsoft.VisualBasic.ChrW(42)
        Me.txtPassWord.Size = New System.Drawing.Size(120, 21)
        Me.txtPassWord.TabIndex = 4
        Me.txtPassWord.Text = ""
        '
        'cbUser
        '
        Me.cbUser.Location = New System.Drawing.Point(88, 32)
        Me.cbUser.Name = "cbUser"
        Me.cbUser.Size = New System.Drawing.Size(121, 20)
        Me.cbUser.TabIndex = 5
        '
        'frmLogin
        '
        Me.AcceptButton = Me.btnOK
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(322, 118)
        Me.Controls.Add(Me.cbUser)
        Me.Controls.Add(Me.txtPassWord)
        Me.Controls.Add(Me.Label2)
        Me.Controls.Add(Me.Label1)
        Me.Controls.Add(Me.btnOK)
        Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle
        Me.MaximizeBox = False
        Me.MinimizeBox = False
        Me.Name = "frmLogin"
        Me.ShowInTaskbar = False
        Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterParent
        Me.Text = "系统登录"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub frmLogin_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load


        cnData.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Jet OLEDB:database password=power;;Data Source= " & Application.StartupPath & "\gongzi.mdb;Persist Security Info=False"



        Try
            cnData.Open()
            daUser.Connection = cnData
            daUser.CommandText = "SELECT Yhmc " & _
                                 "FROM Yhqx "
            rd = daUser.ExecuteReader(CommandBehavior.CloseConnection)
            Do While rd.Read()
                cbUser.Items.Add(Trim(rd.GetString(0)))
            Loop


        Catch ex As Exception
            MessageBox.Show(ex.Message)
        Finally

            rd.Close()
        End Try

    End Sub

    Private Sub btnOK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnOK.Click
        Try
            cnData.Open()
            daPower.Connection = cnData
            daPower.CommandText = "SELECT Yhqx " & _
                                  "FROM Yhqx " & _
                                  "WHERE Yhmc = '" & cbUser.Text & "'" & _
                                  " AND Yhmm = '" & txtPassWord.Text & "'"

            strUserPower = Trim(CType(daPower.ExecuteScalar, String))
        Catch ex As Exception
            MessageBox.Show(ex.Message)
        Finally
            cnData.Close()
        End Try

        If strUserPower = "" Then
            MessageBox.Show("用户名或密码错误！", "身份确认失败", MessageBoxButtons.OK, MessageBoxIcon.Error)
        Else
            strUserName = cbUser.Text
            Me.Close()
        End If
    End Sub

End Class