vb.net 登錄access源代碼【原創】

 

在窗體中加入兩個txt框，兩個按鈕。界面設計如上圖所示。

數據庫中設計access表，adminuser，表中創建username、passwrod兩個文本字段。access文件名稱爲my.mdb.其源代碼如下：

Imports System.Data
Imports System.Data.OleDb

Public Class LoginFrm
    Inherits System.Windows.Forms.Form
    Public ADOcmd As OleDbDataAdapter
    Public ds As DataSet = New DataSet
    Public mytable As Data.DataTable
    Public myrow As Data.DataRow
    Public rownumber As Integer
    Public searchsql As String
    Public cmd As OleDbCommandBuilder
    Public Function ExecuteSQL(ByVal SQL As String, ByVal table As String)
        ADOcmd = New OleDbDataAdapter(SQL, "Provider=Microsoft.Jet.OLEDB.4.0; Data Source=" & Application.StartupPath() & "\my.mdb")
        ADOcmd.Fill(ds, table)
        mytable = ds.Tables.Item(0)
        rownumber = 0
        myrow = mytable.Rows.Item(rownumber)
    End Function

#Region " Windows 窗體設計器生成的代碼 "

    Public Sub New()
        MyBase.New()

        '該調用是 Windows 窗體設計器所必需的。
        InitializeComponent()

        '在 InitializeComponent() 調用之後添加任何初始化

    End Sub

    '窗體重寫 dispose 以清理組件列表。
    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 窗體設計器所必需的
    Private components As System.ComponentModel.IContainer

    '注意: 以下過程是 Windows 窗體設計器所必需的
    '可以使用 Windows 窗體設計器修改此過程。
    '不要使用代碼編輯器修改它。
    Friend WithEvents Label1 As System.Windows.Forms.Label
    Friend WithEvents Label2 As System.Windows.Forms.Label
    Friend WithEvents btn_ok As System.Windows.Forms.Button
    Friend WithEvents btn_cancel As System.Windows.Forms.Button
    Friend WithEvents Txt_Username As System.Windows.Forms.TextBox
    Friend WithEvents Txt_pwd As System.Windows.Forms.TextBox
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.Label1 = New System.Windows.Forms.Label
        Me.Label2 = New System.Windows.Forms.Label
        Me.Txt_Username = New System.Windows.Forms.TextBox
        Me.Txt_pwd = New System.Windows.Forms.TextBox
        Me.btn_ok = New System.Windows.Forms.Button
        Me.btn_cancel = New System.Windows.Forms.Button
        Me.SuspendLayout()
        '
        'Label1
        '
        Me.Label1.AutoSize = True
        Me.Label1.Location = New System.Drawing.Point(48, 32)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(54, 17)
        Me.Label1.TabIndex = 0
        Me.Label1.Text = "用戶名："
        '
        'Label2
        '
        Me.Label2.AutoSize = True
        Me.Label2.Location = New System.Drawing.Point(48, 64)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(54, 17)
        Me.Label2.TabIndex = 1
        Me.Label2.Text = "密  碼："
        '
        'Txt_Username
        '
        Me.Txt_Username.Location = New System.Drawing.Point(112, 32)
        Me.Txt_Username.Name = "Txt_Username"
        Me.Txt_Username.Size = New System.Drawing.Size(96, 21)
        Me.Txt_Username.TabIndex = 2
        Me.Txt_Username.Text = ""
        '
        'Txt_pwd
        '
        Me.Txt_pwd.Location = New System.Drawing.Point(112, 64)
        Me.Txt_pwd.Name = "Txt_pwd"
        Me.Txt_pwd.PasswordChar = Microsoft.VisualBasic.ChrW(42)
        Me.Txt_pwd.Size = New System.Drawing.Size(96, 21)
        Me.Txt_pwd.TabIndex = 3
        Me.Txt_pwd.Text = ""
        '
        'btn_ok
        '
        Me.btn_ok.Location = New System.Drawing.Point(64, 104)
        Me.btn_ok.Name = "btn_ok"
        Me.btn_ok.Size = New System.Drawing.Size(48, 24)
        Me.btn_ok.TabIndex = 4
        Me.btn_ok.Text = "登錄"
        '
        'btn_cancel
        '
        Me.btn_cancel.Location = New System.Drawing.Point(160, 104)
        Me.btn_cancel.Name = "btn_cancel"
        Me.btn_cancel.Size = New System.Drawing.Size(48, 24)
        Me.btn_cancel.TabIndex = 5
        Me.btn_cancel.Text = "關閉"
        '
        'LoginFrm
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(296, 158)
        Me.Controls.Add(Me.btn_cancel)
        Me.Controls.Add(Me.btn_ok)
        Me.Controls.Add(Me.Txt_pwd)
        Me.Controls.Add(Me.Txt_Username)
        Me.Controls.Add(Me.Label2)
        Me.Controls.Add(Me.Label1)
        Me.MaximizeBox = False
        Me.MinimizeBox = False
        Me.Name = "LoginFrm"
        Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
        Me.Text = "登錄"
        Me.ResumeLayout(False)

    End Sub

#End Region

    Private Sub btn_cancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_cancel.Click
        Me.Close()
    End Sub

    Private Sub btn_ok_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_ok.Click
        '定義
        Dim tablename As String
        tablename = "adminuser"
        Dim SearchSQL As String
        SearchSQL = "select username,password from adminuser where username='" & Txt_Username.Text & "'"
        Try
            ExecuteSQL(SearchSQL, tablename)
            If myrow.Item(1) = Txt_pwd.Text Then
                MsgBox("成功登陸")
                Dim FormMain As New FormMain
                FormMain.Show()
                Me.Hide()
            Else
                MsgBox("密碼不正確！", vbOKOnly + vbExclamation, "警告")
                Exit Sub
            End If
        Catch
            MsgBox("無此用戶！", vbOKOnly + vbExclamation, "警告")
        End Try

    End Sub

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

    End Sub

    Private Sub Txt_pwd_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Txt_pwd.KeyDown

        If e.KeyCode = Keys.Enter Then
            btn_ok.Visible = True
            btn_ok.Focus()
        End If
    End Sub

    Private Sub Txt_Username_KeyDown(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles Txt_Username.KeyDown
        If e.KeyCode = Keys.Enter Then
            Txt_pwd.Focus()
        End If
    End Sub
End Class