frm_addbooktype.vb

一个用VB.NET做的图书管理系统,功能比较简单

Imports System.Data.OleDb
Public Class frm_AddBookType
    Inherits System.Windows.Forms.Form
    Dim MyConnection As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & Application.StartupPath & "\library.mdb")
    Dim MyCommand As OleDbCommand
    Dim MyReader As OleDbDataReader

#Region " Windows Form Designer generated code "

    Public Sub New()
        MyBase.New()

        'This call is required by the Windows Form Designer.
        InitializeComponent()

        'Add any initialization after the InitializeComponent() call

    End Sub

    'Form overrides dispose to clean up the component list.
    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

    'Required by the Windows Form Designer
    Private components As System.ComponentModel.IContainer

    'NOTE: The following procedure is required by the Windows Form Designer
    'It can be modified using the Windows Form Designer.  
    'Do not modify it using the code editor.
    Friend WithEvents GroupBox1 As System.Windows.Forms.GroupBox
    Friend WithEvents Label1 As System.Windows.Forms.Label
    Friend WithEvents Label2 As System.Windows.Forms.Label
    Friend WithEvents TxtTypeNo As System.Windows.Forms.TextBox
    Friend WithEvents TxtDescript As System.Windows.Forms.TextBox
    Friend WithEvents BtnAdd As System.Windows.Forms.Button
    Friend WithEvents BtnClear As System.Windows.Forms.Button
    Friend WithEvents Button3 As System.Windows.Forms.Button
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Dim resources As System.ComponentModel.ComponentResourceManager = New System.ComponentModel.ComponentResourceManager(GetType(frm_AddBookType))
        Me.GroupBox1 = New System.Windows.Forms.GroupBox
        Me.TxtDescript = New System.Windows.Forms.TextBox
        Me.TxtTypeNo = New System.Windows.Forms.TextBox
        Me.Label2 = New System.Windows.Forms.Label
        Me.Label1 = New System.Windows.Forms.Label
        Me.BtnAdd = New System.Windows.Forms.Button
        Me.BtnClear = New System.Windows.Forms.Button
        Me.Button3 = New System.Windows.Forms.Button
        Me.GroupBox1.SuspendLayout()
        Me.SuspendLayout()
        '
        'GroupBox1
        '
        Me.GroupBox1.Controls.Add(Me.TxtDescript)
        Me.GroupBox1.Controls.Add(Me.TxtTypeNo)
        Me.GroupBox1.Controls.Add(Me.Label2)
        Me.GroupBox1.Controls.Add(Me.Label1)
        Me.GroupBox1.Location = New System.Drawing.Point(10, 9)
        Me.GroupBox1.Name = "GroupBox1"
        Me.GroupBox1.Size = New System.Drawing.Size(307, 94)
        Me.GroupBox1.TabIndex = 0
        Me.GroupBox1.TabStop = False
        Me.GroupBox1.Text = "书籍类型信息"
        '
        'TxtDescript
        '
        Me.TxtDescript.Location = New System.Drawing.Point(144, 60)
        Me.TxtDescript.Name = "TxtDescript"
        Me.TxtDescript.Size = New System.Drawing.Size(144, 21)
        Me.TxtDescript.TabIndex = 3
        '
        'TxtTypeNo
        '
        Me.TxtTypeNo.Location = New System.Drawing.Point(144, 26)
        Me.TxtTypeNo.Name = "TxtTypeNo"
        Me.TxtTypeNo.Size = New System.Drawing.Size(144, 21)
        Me.TxtTypeNo.TabIndex = 2
        '
        'Label2
        '
        Me.Label2.Location = New System.Drawing.Point(46, 60)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(95, 25)
        Me.Label2.TabIndex = 1
        Me.Label2.Text = "描述"
        '
        'Label1
        '
        Me.Label1.Location = New System.Drawing.Point(24, 26)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(120, 25)
        Me.Label1.TabIndex = 0
        Me.Label1.Text = "类型编号"
        '
        'BtnAdd
        '
        Me.BtnAdd.Location = New System.Drawing.Point(29, 112)
        Me.BtnAdd.Name = "BtnAdd"
        Me.BtnAdd.Size = New System.Drawing.Size(86, 35)
        Me.BtnAdd.TabIndex = 1
        Me.BtnAdd.Text = "添加"
        '
        'BtnClear
        '
        Me.BtnClear.Location = New System.Drawing.Point(115, 112)
        Me.BtnClear.Name = "BtnClear"
        Me.BtnClear.Size = New System.Drawing.Size(87, 35)
        Me.BtnClear.TabIndex = 2
        Me.BtnClear.Text = "重置"
        '
        'Button3
        '
        Me.Button3.Location = New System.Drawing.Point(202, 112)
        Me.Button3.Name = "Button3"
        Me.Button3.Size = New System.Drawing.Size(76, 35)
        Me.Button3.TabIndex = 3
        Me.Button3.Text = "退出"
        '
        'frm_AddBookType
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(328, 161)
        Me.Controls.Add(Me.Button3)
        Me.Controls.Add(Me.BtnClear)
        Me.Controls.Add(Me.BtnAdd)
        Me.Controls.Add(Me.GroupBox1)
        Me.FormBorderStyle = System.Windows.Forms.FormBorderStyle.FixedSingle
        Me.Icon = CType(resources.GetObject("$this.Icon"), System.Drawing.Icon)
        Me.MaximizeBox = False
        Me.MinimizeBox = False
        Me.Name = "frm_AddBookType"
        Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
        Me.Text = "添加书籍类型"
        Me.GroupBox1.ResumeLayout(False)
        Me.GroupBox1.PerformLayout()
        Me.ResumeLayout(False)

    End Sub

#End Region
    Function clearfields()
        TxtTypeNo.Text = ""
        TxtDescript.Text = ""
    End Function
    Function checkTextbox(ByVal t As TextBox) As Boolean
        If t.Text = "" Then
            Return (False)
        Else
            Return True
        End If
    End Function
    Function displayMsg(ByVal myMsgText As String)
        MsgBox(myMsgText, MsgBoxStyle.Information, "图书管管理系统")
    End Function
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        Me.Close()
    End Sub

    Function addBookType()
        MyConnection.Open()
        MyCommand = New OleDbCommand("INSERT INTO BookType VALUES('" & TxtTypeNo.Text & "','" & TxtDescript.Text & "')", MyConnection)
        MyCommand.ExecuteNonQuery()
        MyConnection.Close()
        MyCommand.dispose()
    End Function
    Function checkIfAlreadyExists() As Boolean
        Dim temp As String
        MyConnection.Open()
        MyCommand = New OleDbCommand("SELECT * FROM BookType WHERE Type ='" & TxtTypeNo.Text & "'", MyConnection)
        MyReader = MyCommand.ExecuteReader()
        While MyReader.Read
            temp = MyReader("Type")
        End While
        MyConnection.Close()
        MyReader.Close()
        MyCommand.dispose()
        If temp = TxtTypeNo.Text Then
            Return True
        Else
            If temp <> TxtTypeNo.Text Then
                Return False
            End If
        End If
    End Function





    Private Sub BtnClear_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnClear.Click
        clearfields()
    End Sub


    Private Sub BtnAdd_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnAdd.Click
        If checkTextbox(TxtTypeNo) = False Then
            displayMsg("请输入新的书籍类型编号")
        Else
            If checkIfAlreadyExists() = True Then
                displayMsg("书籍类型编号已经存在，请重新输入")
                Exit Sub
            Else
                If checkTextbox(TxtTypeNo) = True Then
                    TxtDescript.Focus()
                End If
            End If
        End If
        If checkTextbox(TxtDescript) = False Then
            displayMsg("请输入类型描述信息")
            Exit Sub
        Else
            If checkTextbox(TxtDescript) = True Then
                BtnAdd.Focus()
            End If
        End If
        addBookType()
        displayMsg("新的书籍类型信息已被添加到数据库中")
        clearfields()
        TxtTypeNo.Focus()
    End Sub


End Class