login.vb

这是一个商务管理体系

'引用名称空间
Imports System.Data
Imports System.Data.SqlClient
Public Class Login
    Inherits System.Windows.Forms.Form
    'login市登陆正确的信号
    Public login As Integer = 0

#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 Button1 As System.Windows.Forms.Button
    Friend WithEvents Button2 As System.Windows.Forms.Button
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents Label1 As System.Windows.Forms.Label
    Friend WithEvents Label2 As System.Windows.Forms.Label
    Friend WithEvents TextBox2 As System.Windows.Forms.TextBox
    Friend WithEvents SqlDataAdapter1 As System.Data.SqlClient.SqlDataAdapter
    Friend WithEvents SqlSelectCommand1 As System.Data.SqlClient.SqlCommand
    Friend WithEvents SqlInsertCommand1 As System.Data.SqlClient.SqlCommand
    Friend WithEvents SqlUpdateCommand1 As System.Data.SqlClient.SqlCommand
    Friend WithEvents SqlDeleteCommand1 As System.Data.SqlClient.SqlCommand
    Friend WithEvents SqlConnection1 As System.Data.SqlClient.SqlConnection
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Me.Button1 = New System.Windows.Forms.Button()
        Me.Button2 = New System.Windows.Forms.Button()
        Me.TextBox1 = New System.Windows.Forms.TextBox()
        Me.Label1 = New System.Windows.Forms.Label()
        Me.Label2 = New System.Windows.Forms.Label()
        Me.TextBox2 = New System.Windows.Forms.TextBox()
        Me.SqlDataAdapter1 = New System.Data.SqlClient.SqlDataAdapter()
        Me.SqlDeleteCommand1 = New System.Data.SqlClient.SqlCommand()
        Me.SqlConnection1 = New System.Data.SqlClient.SqlConnection()
        Me.SqlInsertCommand1 = New System.Data.SqlClient.SqlCommand()
        Me.SqlSelectCommand1 = New System.Data.SqlClient.SqlCommand()
        Me.SqlUpdateCommand1 = New System.Data.SqlClient.SqlCommand()
        Me.SuspendLayout()
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(208, 8)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(80, 24)
        Me.Button1.TabIndex = 0
        Me.Button1.Text = "登陆"
        '
        'Button2
        '
        Me.Button2.DialogResult = System.Windows.Forms.DialogResult.Cancel
        Me.Button2.Location = New System.Drawing.Point(208, 40)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(80, 24)
        Me.Button2.TabIndex = 1
        Me.Button2.Text = "取消"
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(72, 8)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(120, 20)
        Me.TextBox1.TabIndex = 2
        Me.TextBox1.Text = ""
        '
        'Label1
        '
        Me.Label1.Location = New System.Drawing.Point(16, 8)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(48, 24)
        Me.Label1.TabIndex = 3
        Me.Label1.Text = "用户名"
        '
        'Label2
        '
        Me.Label2.Location = New System.Drawing.Point(16, 40)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(48, 24)
        Me.Label2.TabIndex = 5
        Me.Label2.Text = "密码"
        '
        'TextBox2
        '
        Me.TextBox2.AcceptsTab = True
        Me.TextBox2.Location = New System.Drawing.Point(72, 40)
        Me.TextBox2.Name = "TextBox2"
        Me.TextBox2.PasswordChar = Microsoft.VisualBasic.ChrW(42)
        Me.TextBox2.Size = New System.Drawing.Size(120, 20)
        Me.TextBox2.TabIndex = 4
        Me.TextBox2.Text = ""
        '
        'SqlDataAdapter1
        '
        Me.SqlDataAdapter1.DeleteCommand = Me.SqlDeleteCommand1
        Me.SqlDataAdapter1.InsertCommand = Me.SqlInsertCommand1
        Me.SqlDataAdapter1.SelectCommand = Me.SqlSelectCommand1
        Me.SqlDataAdapter1.TableMappings.AddRange(New System.Data.Common.DataTableMapping() {New System.Data.Common.DataTableMapping("Table", "客户信息", New System.Data.Common.DataColumnMapping() {New System.Data.Common.DataColumnMapping("Username", "Username"), New System.Data.Common.DataColumnMapping("Password", "Password"), New System.Data.Common.DataColumnMapping("id", "id")})})
        Me.SqlDataAdapter1.UpdateCommand = Me.SqlUpdateCommand1
        '
        'SqlDeleteCommand1
        '
        Me.SqlDeleteCommand1.CommandText = "DELETE FROM 客户信息 WHERE (id = @Original_id) AND (Password = @Original_Password) AN" & _
        "D (Username = @Original_Username)"
        Me.SqlDeleteCommand1.Connection = Me.SqlConnection1
        Me.SqlDeleteCommand1.Parameters.Add(New System.Data.SqlClient.SqlParameter("@Original_id", System.Data.SqlDbType.Int, 4, System.Data.ParameterDirection.Input, False, CType(0, Byte), CType(0, Byte), "id", System.Data.DataRowVersion.Original, Nothing))
        Me.SqlDeleteCommand1.Parameters.Add(New System.Data.SqlClient.SqlParameter("@Original_Password", System.Data.SqlDbType.VarChar, 10, System.Data.ParameterDirection.Input, False, CType(0, Byte), CType(0, Byte), "Password", System.Data.DataRowVersion.Original, Nothing))
        Me.SqlDeleteCommand1.Parameters.Add(New System.Data.SqlClient.SqlParameter("@Original_Username", System.Data.SqlDbType.VarChar, 10, System.Data.ParameterDirection.Input, False, CType(0, Byte), CType(0, Byte), "Username", System.Data.DataRowVersion.Original, Nothing))
        '
        'SqlConnection1
        '
        Me.SqlConnection1.ConnectionString = "data source=localhost;initial catalog=Shangwu;persist security info=False;user id" & _
        "=sa;password=lovess;workstation id=LIGHT257;packet size=4096"
        '
        'SqlInsertCommand1
        '
        Me.SqlInsertCommand1.CommandText = "INSERT INTO 客户信息(Username, Password, id) VALUES (@Username, @Password, @id); SELE" & _
        "CT Username, Password, id FROM 客户信息 WHERE (id = @id)"
        Me.SqlInsertCommand1.Connection = Me.SqlConnection1
        Me.SqlInsertCommand1.Parameters.Add(New System.Data.SqlClient.SqlParameter("@Username", System.Data.SqlDbType.VarChar, 10, "Username"))
        Me.SqlInsertCommand1.Parameters.Add(New System.Data.SqlClient.SqlParameter("@Password", System.Data.SqlDbType.VarChar, 10, "Password"))
        Me.SqlInsertCommand1.Parameters.Add(New System.Data.SqlClient.SqlParameter("@id", System.Data.SqlDbType.Int, 4, "id"))
        '
        'SqlSelectCommand1
        '
        Me.SqlSelectCommand1.CommandText = "SELECT Username, Password, id FROM 客户信息 WHERE (级别 = '管理员')"
        Me.SqlSelectCommand1.Connection = Me.SqlConnection1
        '
        'SqlUpdateCommand1
        '
        Me.SqlUpdateCommand1.CommandText = "UPDATE 客户信息 SET Username = @Username, Password = @Password, id = @id WHERE (id = " & _
        "@Original_id) AND (Password = @Original_Password) AND (Username = @Original_User" & _
        "name); SELECT Username, Password, id FROM 客户信息 WHERE (id = @id)"
        Me.SqlUpdateCommand1.Connection = Me.SqlConnection1
        Me.SqlUpdateCommand1.Parameters.Add(New System.Data.SqlClient.SqlParameter("@Username", System.Data.SqlDbType.VarChar, 10, "Username"))
        Me.SqlUpdateCommand1.Parameters.Add(New System.Data.SqlClient.SqlParameter("@Password", System.Data.SqlDbType.VarChar, 10, "Password"))
        Me.SqlUpdateCommand1.Parameters.Add(New System.Data.SqlClient.SqlParameter("@id", System.Data.SqlDbType.Int, 4, "id"))
        Me.SqlUpdateCommand1.Parameters.Add(New System.Data.SqlClient.SqlParameter("@Original_id", System.Data.SqlDbType.Int, 4, System.Data.ParameterDirection.Input, False, CType(0, Byte), CType(0, Byte), "id", System.Data.DataRowVersion.Original, Nothing))
        Me.SqlUpdateCommand1.Parameters.Add(New System.Data.SqlClient.SqlParameter("@Original_Password", System.Data.SqlDbType.VarChar, 10, System.Data.ParameterDirection.Input, False, CType(0, Byte), CType(0, Byte), "Password", System.Data.DataRowVersion.Original, Nothing))
        Me.SqlUpdateCommand1.Parameters.Add(New System.Data.SqlClient.SqlParameter("@Original_Username", System.Data.SqlDbType.VarChar, 10, System.Data.ParameterDirection.Input, False, CType(0, Byte), CType(0, Byte), "Username", System.Data.DataRowVersion.Original, Nothing))
        '
        'Login
        '
        Me.AcceptButton = Me.Button1
        Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
        Me.CancelButton = Me.Button2
        Me.ClientSize = New System.Drawing.Size(298, 74)
        Me.ControlBox = False
        Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.Label2, Me.TextBox2, Me.Label1, Me.TextBox1, Me.Button2, Me.Button1})
        Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedToolWindow
        Me.MaximizeBox = False
        Me.MinimizeBox = False
        Me.Name = "Login"
        Me.ShowInTaskbar = False
        Me.Text = "Login"
        Me.ResumeLayout(False)

    End Sub

#End Region

    '登陆按钮的事件
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        'nsql是SQL语句
        Dim nsql As String
        '给出错误陷阱
        On Error GoTo 10
        'ncomm是SQL命令
        Dim ncomm As New SqlCommand()
        '生成SQL语句
        nsql = "Select password from 客户信息 where 级别=" + Chr(39) + "管理员" + Chr(39) + " and  username=" + Chr(39) + TextBox1.Text + Chr(39)
        '定义SQLdataReader
        Dim myreader As SqlDataReader
        '打开数据库连接
        SqlConnection1.Open()
        '指定数据库连接和SQL语句
        ncomm.Connection = SqlConnection1
        ncomm.CommandText = nsql
        '读入记录
        myreader = ncomm.ExecuteReader()
        myreader.Read()
        '判断密码是不是相等
        Dim pass As String = myreader.GetString(0)
        '相等的情况
        If pass = TextBox2.Text Then
            '关闭DataReader和数据库连接
            myreader.Close()
            SqlConnection1.Close()
            '登陆成功信号
            login = 1
            '关闭对话框
            Me.Close()
        End If
        '密码或者帐号错误的情况，弹出信息
10:     If login <> 1 Then MsgBox("管理员信息不正确！")
        '关闭DataReader和数据库连接
        myreader.Close()
        SqlConnection1.Close()
    End Sub


    '取消按钮的事件
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Me.Close()
    End Sub


End Class