frmlogin.vb

这是一个教务信息管理系统！

Imports System.Data
'引入数据库操作类命名空间
Imports System.Data.OleDb
'引入ADO.NET操作命名空间
Public Class FrmLogin
    Inherits System.Windows.Forms.Form
    Public ADOcmd As OleDbDataAdapter
    Public ds As DataSet = New DataSet()
    '建立DataSet对象 
    Public mytable As Data.DataTable
    '建立表单对象
    Public myrow As Data.DataRow
    '建立数据行对象
    Public rownumber As Integer
    '定义一个整型变量来存放当前行数
    Public SearchSQL As String
    Public cmd As OleDbCommandBuilder

#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 Label1 As System.Windows.Forms.Label
    Friend WithEvents Label2 As System.Windows.Forms.Label
    Friend WithEvents Label3 As System.Windows.Forms.Label
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Button2 As System.Windows.Forms.Button
    Friend WithEvents Label4 As System.Windows.Forms.Label
    Friend WithEvents TxtUserName As System.Windows.Forms.TextBox
    Friend WithEvents TxtUserPassword As System.Windows.Forms.TextBox
    Friend WithEvents ErrorProvider1 As System.Windows.Forms.ErrorProvider
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.Label1 = New System.Windows.Forms.Label()
        Me.Label2 = New System.Windows.Forms.Label()
        Me.Label3 = New System.Windows.Forms.Label()
        Me.TxtUserName = New System.Windows.Forms.TextBox()
        Me.TxtUserPassword = New System.Windows.Forms.TextBox()
        Me.Button1 = New System.Windows.Forms.Button()
        Me.Button2 = New System.Windows.Forms.Button()
        Me.Label4 = New System.Windows.Forms.Label()
        Me.ErrorProvider1 = New System.Windows.Forms.ErrorProvider()
        Me.SuspendLayout()
        '
        'Label1
        '
        Me.Label1.AutoSize = True
        Me.Label1.Font = New System.Drawing.Font("华文彩云", 26.25!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.Label1.ForeColor = System.Drawing.SystemColors.Desktop
        Me.Label1.Location = New System.Drawing.Point(24, 24)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(230, 37)
        Me.Label1.TabIndex = 0
        Me.Label1.Text = "教务信息系统"
        '
        'Label2
        '
        Me.Label2.AutoSize = True
        Me.Label2.Font = New System.Drawing.Font("宋体", 10.5!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.Label2.Location = New System.Drawing.Point(32, 72)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(49, 16)
        Me.Label2.TabIndex = 1
        Me.Label2.Text = "用户名"
        '
        'Label3
        '
        Me.Label3.AutoSize = True
        Me.Label3.Font = New System.Drawing.Font("宋体", 10.5!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.Label3.Location = New System.Drawing.Point(32, 104)
        Me.Label3.Name = "Label3"
        Me.Label3.Size = New System.Drawing.Size(34, 16)
        Me.Label3.TabIndex = 2
        Me.Label3.Text = "密码"
        '
        'TxtUserName
        '
        Me.TxtUserName.Location = New System.Drawing.Point(112, 72)
        Me.TxtUserName.Name = "TxtUserName"
        Me.TxtUserName.TabIndex = 3
        Me.TxtUserName.Text = ""
        '
        'TxtUserPassword
        '
        Me.TxtUserPassword.Location = New System.Drawing.Point(112, 104)
        Me.TxtUserPassword.Name = "TxtUserPassword"
        Me.TxtUserPassword.PasswordChar = Microsoft.VisualBasic.ChrW(42)
        Me.TxtUserPassword.TabIndex = 4
        Me.TxtUserPassword.Text = ""
        '
        'Button1
        '
        Me.Button1.Font = New System.Drawing.Font("宋体", 10.5!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.Button1.Location = New System.Drawing.Point(152, 144)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(75, 32)
        Me.Button1.TabIndex = 5
        Me.Button1.Text = "取消"
        '
        'Button2
        '
        Me.Button2.Font = New System.Drawing.Font("宋体", 10.5!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.Button2.Location = New System.Drawing.Point(32, 144)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(75, 32)
        Me.Button2.TabIndex = 6
        Me.Button2.Text = "确定"
        '
        'Label4
        '
        Me.Label4.Font = New System.Drawing.Font("宋体", 12.0!, System.Drawing.FontStyle.Bold, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.Label4.Location = New System.Drawing.Point(8, 192)
        Me.Label4.Name = "Label4"
        Me.Label4.Size = New System.Drawing.Size(272, 23)
        Me.Label4.TabIndex = 7
        Me.Label4.Text = "版权所有：Yin SoftWare Corp."
        '
        'ErrorProvider1
        '
        Me.ErrorProvider1.DataMember = Nothing
        '
        'FrmLogin
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(272, 221)
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.Label4, Me.Button2, Me.Button1, Me.TxtUserPassword, Me.TxtUserName, Me.Label3, Me.Label2, Me.Label1})
        Me.Name = "FrmLogin"
        Me.Text = "登录"
        Me.ResumeLayout(False)

    End Sub

#End Region



    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Me.Dispose()
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim tablename As String
        tablename = "userID"  '表的名称
        SearchSQL = "SELECT 用户名, 密码 FROM userID WHERE (用户名 = '" & TxtUserName.Text & " ') "
        Try
            ExecuteSQL(SearchSQL, tablename)  '查询函数

            If myrow.Item(1) = TxtUserPassword.Text Then  '比较输入密码和数据库的密码
                Dim newFrmmain As New FrmMain()
                newFrmmain.Show()
                Me.Hide()
            Else
                Exit Sub
            End If
        Catch
            MsgBox("没有该用户", vbOKOnly + vbExclamation, "警告")
        End Try
    End Sub
    Private Sub TxtUserName_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles TxtUserName.Validating
        If TxtUserName.Text = "" Then
            ErrorProvider1.SetError(TxtUserName, "用户名不能为空")
        Else
            ErrorProvider1.SetError(TxtUserName, "")
        End If
    End Sub

    Private Sub TxtUserPassword_Validating(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles TxtUserPassword.Validating
        If TxtUserPassword.Text = "" Then
            ErrorProvider1.SetError(TxtUserPassword, "密码不能为空")
        Else
            ErrorProvider1.SetError(TxtUserPassword, "")
        End If
    End Sub

    Public Function ExecuteSQL(ByVal SQL As String, ByVal table As String)
        Try
            '建立ADODataSetCommand对象
            '数据库查询函数
            ADOcmd = New OleDbDataAdapter(SQL, "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=d:\冯军\student.mdb")
            '建立ADODataSetCommand对象
            ADOcmd.Fill(ds, table) '取得表单
            mytable = ds.Tables.Item(0) '取得名为table的表
            rownumber = 0 '设置为第一行
            myrow = mytable.Rows.Item(rownumber)
            '取得第一行数据
        Catch
            MsgBox(Err.Description)
        End Try
    End Function

   

End Class