frmlogin.vb

单机版餐饮服务系统,结合了SqlServer数据库

Imports System
Imports System.Data
Imports System.DBNull
Imports System.Drawing
Imports System.Data.SqlClient

Namespace HZC.DinningService

    Public Class frmLogin
        Inherits System.Windows.Forms.Form

        Private _User As String = String.Empty
        Private _Password As String = String.Empty
        Private _LogonInfo As String = String.Empty
        Private _StartPath As String = Application.StartupPath & "\ApplicationInitials.ini"
       
#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 lbTitle As System.Windows.Forms.Label
        Friend WithEvents btnCancel As System.Windows.Forms.Button
        Friend WithEvents btnLogin As System.Windows.Forms.Button
        Friend WithEvents txtPassword As System.Windows.Forms.TextBox
        Friend WithEvents txtUserName As System.Windows.Forms.TextBox
        Friend WithEvents lbPassword As System.Windows.Forms.Label
        Friend WithEvents lbUserName As System.Windows.Forms.Label
        Friend WithEvents LoginErrorProvider As System.Windows.Forms.ErrorProvider
        <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
            Dim resources As System.Resources.ResourceManager = New System.Resources.ResourceManager(GetType(frmLogin))
            Me.lbTitle = New System.Windows.Forms.Label
            Me.btnCancel = New System.Windows.Forms.Button
            Me.btnLogin = New System.Windows.Forms.Button
            Me.txtPassword = New System.Windows.Forms.TextBox
            Me.txtUserName = New System.Windows.Forms.TextBox
            Me.lbPassword = New System.Windows.Forms.Label
            Me.lbUserName = New System.Windows.Forms.Label
            Me.LoginErrorProvider = New System.Windows.Forms.ErrorProvider
            Me.SuspendLayout()
            '
            'lbTitle
            '
            Me.lbTitle.Font = New System.Drawing.Font("华文行楷", 24.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
            Me.lbTitle.ForeColor = System.Drawing.Color.FromArgb(CType(0, Byte), CType(0, Byte), CType(192, Byte))
            Me.lbTitle.Location = New System.Drawing.Point(24, 24)
            Me.lbTitle.Name = "lbTitle"
            Me.lbTitle.Size = New System.Drawing.Size(392, 56)
            Me.lbTitle.TabIndex = 0
            Me.lbTitle.Text = "单机版餐饮服务"
            Me.lbTitle.TextAlign = System.Drawing.ContentAlignment.MiddleCenter
            '
            'btnCancel
            '
            Me.btnCancel.DialogResult = System.Windows.Forms.DialogResult.Cancel
            Me.btnCancel.FlatStyle = System.Windows.Forms.FlatStyle.Popup
            Me.btnCancel.Font = New System.Drawing.Font("宋体", 9.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
            Me.btnCancel.ForeColor = System.Drawing.Color.Navy
            Me.btnCancel.Location = New System.Drawing.Point(232, 224)
            Me.btnCancel.Name = "btnCancel"
            Me.btnCancel.Size = New System.Drawing.Size(72, 24)
            Me.btnCancel.TabIndex = 13
            Me.btnCancel.Text = "取消"
            '
            'btnLogin
            '
            Me.btnLogin.FlatStyle = System.Windows.Forms.FlatStyle.Popup
            Me.btnLogin.Font = New System.Drawing.Font("宋体", 9.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
            Me.btnLogin.ForeColor = System.Drawing.Color.Navy
            Me.btnLogin.Location = New System.Drawing.Point(144, 224)
            Me.btnLogin.Name = "btnLogin"
            Me.btnLogin.Size = New System.Drawing.Size(72, 24)
            Me.btnLogin.TabIndex = 12
            Me.btnLogin.Text = "登录"
            '
            'txtPassword
            '
            Me.txtPassword.BackColor = System.Drawing.SystemColors.Info
            Me.txtPassword.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle
            Me.txtPassword.ForeColor = System.Drawing.Color.FromArgb(CType(0, Byte), CType(0, Byte), CType(192, Byte))
            Me.LoginErrorProvider.SetIconPadding(Me.txtPassword, 4)
            Me.txtPassword.Location = New System.Drawing.Point(192, 176)
            Me.txtPassword.MaxLength = 15
            Me.txtPassword.Name = "txtPassword"
            Me.txtPassword.PasswordChar = Microsoft.VisualBasic.ChrW(42)
            Me.txtPassword.Size = New System.Drawing.Size(112, 21)
            Me.txtPassword.TabIndex = 11
            Me.txtPassword.Text = "123456789"
            '
            'txtUserName
            '
            Me.txtUserName.AutoSize = False
            Me.txtUserName.BackColor = System.Drawing.SystemColors.Info
            Me.txtUserName.BorderStyle = System.Windows.Forms.BorderStyle.FixedSingle
            Me.txtUserName.ForeColor = System.Drawing.Color.FromArgb(CType(0, Byte), CType(0, Byte), CType(192, Byte))
            Me.LoginErrorProvider.SetIconPadding(Me.txtUserName, 4)
            Me.txtUserName.Location = New System.Drawing.Point(192, 128)
            Me.txtUserName.MaxLength = 15
            Me.txtUserName.Name = "txtUserName"
            Me.txtUserName.Size = New System.Drawing.Size(112, 21)
            Me.txtUserName.TabIndex = 10
            Me.txtUserName.Text = "Administrator"
            '
            'lbPassword
            '
            Me.lbPassword.ForeColor = System.Drawing.Color.Navy
            Me.lbPassword.Location = New System.Drawing.Point(112, 176)
            Me.lbPassword.Name = "lbPassword"
            Me.lbPassword.Size = New System.Drawing.Size(80, 24)
            Me.lbPassword.TabIndex = 9
            Me.lbPassword.Text = "登录密码："
            Me.lbPassword.TextAlign = System.Drawing.ContentAlignment.MiddleCenter
            '
            'lbUserName
            '
            Me.lbUserName.ForeColor = System.Drawing.Color.Navy
            Me.lbUserName.Location = New System.Drawing.Point(112, 128)
            Me.lbUserName.Name = "lbUserName"
            Me.lbUserName.Size = New System.Drawing.Size(80, 24)
            Me.lbUserName.TabIndex = 8
            Me.lbUserName.Text = "登录账号："
            Me.lbUserName.TextAlign = System.Drawing.ContentAlignment.MiddleCenter
            '
            'LoginErrorProvider
            '
            Me.LoginErrorProvider.BlinkRate = 100
            Me.LoginErrorProvider.ContainerControl = Me
            '
            'frmLogin
            '
            Me.AcceptButton = Me.btnLogin
            Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
            Me.CancelButton = Me.btnCancel
            Me.ClientSize = New System.Drawing.Size(434, 288)
            Me.Controls.Add(Me.btnCancel)
            Me.Controls.Add(Me.btnLogin)
            Me.Controls.Add(Me.txtPassword)
            Me.Controls.Add(Me.txtUserName)
            Me.Controls.Add(Me.lbPassword)
            Me.Controls.Add(Me.lbUserName)
            Me.Controls.Add(Me.lbTitle)
            Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedDialog
            Me.Icon = CType(resources.GetObject("$this.Icon"), System.Drawing.Icon)
            Me.MaximizeBox = False
            Me.Name = "frmLogin"
            Me.ShowInTaskbar = False
            Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
            Me.Text = "登录单机版餐饮服务系统"
            Me.ResumeLayout(False)

        End Sub

#End Region

        Public ReadOnly Property GetLogonInfo() As String
            Get
                Return _LogonInfo
            End Get
        End Property

        Private Sub btnCancel_Click( _
                    ByVal sender As System.Object, _
                    ByVal e As System.EventArgs _
                    ) Handles btnCancel.Click
            If MsgBox("您真的不登录餐饮服务管理系统吗？", _
            MsgBoxStyle.YesNo + MsgBoxStyle.Question, "退出登录系统") _
            = MsgBoxResult.Yes Then
                Application.Exit()
            Else
                Exit Sub
            End If
        End Sub

        Private Sub frmLogin_Closing(ByVal sender As Object, _
                                   ByVal e As System.ComponentModel.CancelEventArgs) _
                                   Handles MyBase.Closing
            If MsgBox("您真的不登录餐饮服务管理系统吗？", _
            MsgBoxStyle.YesNo + MsgBoxStyle.Question, "退出登录系统") _
            = MsgBoxResult.Yes Then
                e.Cancel = False
            Else
                e.Cancel = True
            End If
        End Sub

        Private Sub txtUserName_Validated( _
                    ByVal sender As Object, _
                    ByVal e As System.EventArgs) _
                    Handles txtUserName.Validated
            If IsUserNameValid() Then
                LoginErrorProvider.SetError(txtUserName, String.Empty)
            Else
                LoginErrorProvider.SetError(txtUserName, "登录帐号不能为空")
            End If
        End Sub

        Private Sub txtPassword_Validated( _
                    ByVal sender As Object, _
                    ByVal e As System.EventArgs) _
                    Handles txtPassword.Validated
            If IsPasswordValid() Then
                LoginErrorProvider.SetError(txtPassword, String.Empty)
            Else
                LoginErrorProvider.SetError(txtPassword, "登录密码不能为空")
            End If
        End Sub

        Private Function IsUserNameValid() As Boolean
            Return (txtUserName.TextLength > 0)
        End Function

        Private Function IsPasswordValid() As Boolean
            Return (txtPassword.TextLength > 0)
        End Function

        Private Sub btnLogin_Click( _
                    ByVal sender As System.Object, _
                    ByVal e As System.EventArgs) _
                    Handles btnLogin.Click
            _User = txtUserName.Text.Trim
            _Password = txtPassword.Text.Trim
            If (_User = String.Empty) Or (_Password = String.Empty) Then
                Throw New ArgumentNullException
            End If
            _LogonInfo = Logon.Authenticate(_User, _Password)
            If Me.GetLogonInfo = String.Empty Then
                Exit Sub
            End If
            Dim frmMainWindows As New frmMain
            frmMainWindows.LogonInfo = Me.GetLogonInfo
            frmMainWindows.Show()
            Me.Finalize()
        End Sub

        Private Sub frmLogin_Load( _
                    ByVal sender As System.Object, _
                    ByVal e As System.EventArgs _
                    ) Handles MyBase.Load
            AccessToDatabase.InitializeSqlServer(_StartPath)
            If AccessToDatabase.ConnectToDataBase() = False Then
                MsgBox("连接数据库失败，请检查数据库的连接参数。", _
                MsgBoxStyle.OKOnly + MsgBoxStyle.Exclamation, "连接数据库失败")
                Application.Exit()
            End If
        End Sub

    End Class

End Namespace