frmlogin.vb

这是我用VB和SQL制作的教材购销系统,希望大家提出宝贵意见.

Public Class Form1
    Inherits System.Windows.Forms.Form
    Dim user, password, sqlstr As String

#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 TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents Label3 As System.Windows.Forms.Label
    Friend WithEvents TextBox2 As System.Windows.Forms.TextBox
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Button2 As System.Windows.Forms.Button
    Friend WithEvents Label4 As System.Windows.Forms.Label
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.Label1 = New System.Windows.Forms.Label
        Me.Label2 = New System.Windows.Forms.Label
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.Label3 = New System.Windows.Forms.Label
        Me.TextBox2 = 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.SuspendLayout()
        '
        'Label1
        '
        Me.Label1.Font = New System.Drawing.Font("楷体_GB2312", 23.25!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.Label1.ForeColor = System.Drawing.Color.Blue
        Me.Label1.ImageAlign = System.Drawing.ContentAlignment.BottomCenter
        Me.Label1.Location = New System.Drawing.Point(40, 72)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(304, 40)
        Me.Label1.TabIndex = 0
        Me.Label1.Text = "欢迎使用教材购销系统"
        '
        'Label2
        '
        Me.Label2.Font = New System.Drawing.Font("楷体_GB2312", 12.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.Label2.Location = New System.Drawing.Point(64, 128)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(72, 24)
        Me.Label2.TabIndex = 1
        Me.Label2.Text = "用户名:"
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(152, 128)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(96, 21)
        Me.TextBox1.TabIndex = 2
        Me.TextBox1.Text = ""
        '
        'Label3
        '
        Me.Label3.Font = New System.Drawing.Font("楷体_GB2312", 12.0!, System.Drawing.FontStyle.Regular, System.Drawing.GraphicsUnit.Point, CType(134, Byte))
        Me.Label3.Location = New System.Drawing.Point(64, 176)
        Me.Label3.Name = "Label3"
        Me.Label3.Size = New System.Drawing.Size(64, 24)
        Me.Label3.TabIndex = 3
        Me.Label3.Text = "密 码 :"
        '
        'TextBox2
        '
        Me.TextBox2.Location = New System.Drawing.Point(152, 168)
        Me.TextBox2.Name = "TextBox2"
        Me.TextBox2.PasswordChar = Microsoft.VisualBasic.ChrW(42)
        Me.TextBox2.Size = New System.Drawing.Size(96, 21)
        Me.TextBox2.TabIndex = 4
        Me.TextBox2.Text = ""
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(80, 216)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(56, 24)
        Me.Button1.TabIndex = 5
        Me.Button1.Text = "登陆"
        '
        'Button2
        '
        Me.Button2.Location = New System.Drawing.Point(192, 216)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(56, 24)
        Me.Button2.TabIndex = 6
        Me.Button2.Text = "取消"
        '
        'Label4
        '
        Me.Label4.Location = New System.Drawing.Point(56, 256)
        Me.Label4.Name = "Label4"
        Me.Label4.Size = New System.Drawing.Size(224, 40)
        Me.Label4.TabIndex = 7
        Me.Label4.Text = "提示：第一次登陆用户名为""a""，密码为""a"""
        '
        'Form1
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(368, 333)
        Me.Controls.Add(Me.Label4)
        Me.Controls.Add(Me.Button2)
        Me.Controls.Add(Me.Button1)
        Me.Controls.Add(Me.TextBox2)
        Me.Controls.Add(Me.TextBox1)
        Me.Controls.Add(Me.Label3)
        Me.Controls.Add(Me.Label2)
        Me.Controls.Add(Me.Label1)
        Me.Name = "Form1"
        Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
        Me.Text = "frmlogin"
        Me.ResumeLayout(False)

    End Sub

#End Region
   
    
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        user = Me.TextBox1.Text.Trim
        password = Me.TextBox2.Text.Trim
        sqlstr = "SELECT * FROM log WHERE user= " & _
        "'" & user & "' AND password='" & password & "'"
        Dim objDataRow As DataRow
        Try
            objDataRow = GetDataFromDB(sqlstr).Tables(0).Rows(0)
        Catch
            MsgBox("密码和账号不符，请重试，并检查该账号是否存在。", _
            MsgBoxStyle.Information + MsgBoxStyle.OKOnly, "系统登录失败")
            Me.TextBox2.Text = ""
            Exit Sub
        End Try
        Dim frm As New Frmmain
        frm.Show()
        Me.Finalize()
    End Sub

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        If MsgBox("您真的不登教材购销系统吗？", _
        MsgBoxStyle.YesNo + MsgBoxStyle.Question, "退出登录系统") _
        = MsgBoxResult.Yes Then
            Application.Exit()
        Else
            Exit Sub
        End If
    End Sub

End Class