frm_addnewcharges.vb

一个用VB.NET做的图书管理系统,功能比较简单

Imports System.Data.OleDb
Imports System.DateTime
Imports System.Math
Public Class frm_AddNewCharges
    Inherits System.Windows.Forms.Form
    Dim MyConnection As New OleDbConnection("Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" & Application.StartupPath & "\Library.mdb")
    Dim MyCommand
    Dim e As Exception
    Dim MyCommand2
    Dim MyReader As OleDbDataReader
    Dim MyReader2 As OleDbDataReader
    Dim dbset As New DataSet
    Dim dataA
    Dim currentDate As Date
    Dim lockedUser As String

#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 Label1 As System.Windows.Forms.Label
    Friend WithEvents Label2 As System.Windows.Forms.Label
    Friend WithEvents GroupBox1 As System.Windows.Forms.GroupBox
    Friend WithEvents TextBox1 As System.Windows.Forms.TextBox
    Friend WithEvents TextBox2 As System.Windows.Forms.TextBox
    Friend WithEvents Label3 As System.Windows.Forms.Label
    Friend WithEvents TextBox3 As System.Windows.Forms.TextBox
    Friend WithEvents Button1 As System.Windows.Forms.Button
    Friend WithEvents Button2 As System.Windows.Forms.Button
    Friend WithEvents Button3 As System.Windows.Forms.Button
    Friend WithEvents TextBox4 As System.Windows.Forms.TextBox
    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
        Dim resources As System.ComponentModel.ComponentResourceManager = New System.ComponentModel.ComponentResourceManager(GetType(frm_AddNewCharges))
        Me.Label1 = New System.Windows.Forms.Label
        Me.Label2 = New System.Windows.Forms.Label
        Me.GroupBox1 = New System.Windows.Forms.GroupBox
        Me.TextBox3 = New System.Windows.Forms.TextBox
        Me.Label3 = New System.Windows.Forms.Label
        Me.TextBox2 = New System.Windows.Forms.TextBox
        Me.TextBox1 = New System.Windows.Forms.TextBox
        Me.Button1 = New System.Windows.Forms.Button
        Me.Button2 = New System.Windows.Forms.Button
        Me.Button3 = New System.Windows.Forms.Button
        Me.TextBox4 = New System.Windows.Forms.TextBox
        Me.GroupBox1.SuspendLayout()
        Me.SuspendLayout()
        '
        'Label1
        '
        Me.Label1.Location = New System.Drawing.Point(43, 26)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(120, 25)
        Me.Label1.TabIndex = 0
        Me.Label1.Text = "费用编号"
        '
        'Label2
        '
        Me.Label2.Location = New System.Drawing.Point(43, 69)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(120, 25)
        Me.Label2.TabIndex = 1
        Me.Label2.Text = "费用描述"
        '
        'GroupBox1
        '
        Me.GroupBox1.Controls.Add(Me.TextBox3)
        Me.GroupBox1.Controls.Add(Me.Label3)
        Me.GroupBox1.Controls.Add(Me.TextBox2)
        Me.GroupBox1.Controls.Add(Me.TextBox1)
        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(364, 155)
        Me.GroupBox1.TabIndex = 2
        Me.GroupBox1.TabStop = False
        Me.GroupBox1.Text = "书籍费用信息"
        '
        'TextBox3
        '
        Me.TextBox3.Location = New System.Drawing.Point(154, 112)
        Me.TextBox3.Name = "TextBox3"
        Me.TextBox3.Size = New System.Drawing.Size(192, 21)
        Me.TextBox3.TabIndex = 5
        '
        'Label3
        '
        Me.Label3.Location = New System.Drawing.Point(65, 112)
        Me.Label3.Name = "Label3"
        Me.Label3.Size = New System.Drawing.Size(120, 25)
        Me.Label3.TabIndex = 4
        Me.Label3.Text = "费用"
        '
        'TextBox2
        '
        Me.TextBox2.Location = New System.Drawing.Point(154, 69)
        Me.TextBox2.Name = "TextBox2"
        Me.TextBox2.Size = New System.Drawing.Size(192, 21)
        Me.TextBox2.TabIndex = 3
        '
        'TextBox1
        '
        Me.TextBox1.Location = New System.Drawing.Point(154, 26)
        Me.TextBox1.Name = "TextBox1"
        Me.TextBox1.Size = New System.Drawing.Size(192, 21)
        Me.TextBox1.TabIndex = 2
        '
        'Button1
        '
        Me.Button1.Location = New System.Drawing.Point(49, 177)
        Me.Button1.Name = "Button1"
        Me.Button1.Size = New System.Drawing.Size(96, 34)
        Me.Button1.TabIndex = 3
        Me.Button1.Text = "添加"
        '
        'Button2
        '
        Me.Button2.Location = New System.Drawing.Point(145, 177)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(96, 34)
        Me.Button2.TabIndex = 4
        Me.Button2.Text = "重置"
        '
        'Button3
        '
        Me.Button3.Location = New System.Drawing.Point(241, 177)
        Me.Button3.Name = "Button3"
        Me.Button3.Size = New System.Drawing.Size(96, 34)
        Me.Button3.TabIndex = 5
        Me.Button3.Text = "退出"
        '
        'TextBox4
        '
        Me.TextBox4.Location = New System.Drawing.Point(528, 78)
        Me.TextBox4.Name = "TextBox4"
        Me.TextBox4.Size = New System.Drawing.Size(120, 21)
        Me.TextBox4.TabIndex = 6
        '
        'frm_AddNewCharges
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(397, 224)
        Me.Controls.Add(Me.TextBox4)
        Me.Controls.Add(Me.Button3)
        Me.Controls.Add(Me.Button2)
        Me.Controls.Add(Me.Button1)
        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_AddNewCharges"
        Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
        Me.Text = "添加书籍费用信息"
        Me.GroupBox1.ResumeLayout(False)
        Me.GroupBox1.PerformLayout()
        Me.ResumeLayout(False)
        Me.PerformLayout()

    End Sub

#End Region

    Function addCharges()
        MyConnection.Open()
        MyCommand = New OleDbCommand("INSERT INTO Charges VALUES('" & TextBox1.Text & "','" & TextBox2.Text & "', '" & TextBox3.Text & "')", MyConnection)
        MyCommand.ExecuteNonQuery()
        MyConnection.Close()
        MyCommand.dispose()
    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, "图书馆管理系统")
    End Function
    Private Sub TextBox1_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox1.KeyPress
        Dim strChar As String
        strChar = e.KeyChar
        Select Case strChar
            Case ChrW(System.Windows.Forms.Keys.Enter)
                If checkTextbox(TextBox1) = False Then
                    displayMsg("Please fill in the textbox")
                Else
                    If checkTextbox(TextBox1) = True Then
                        TextBox2.Focus()
                    End If
                End If
            Case Else
                'do nothing
        End Select
    End Sub
    Private Sub TextBox2_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox2.KeyPress
        Dim strChar As String
        strChar = e.KeyChar
        Select Case strChar
            Case ChrW(System.Windows.Forms.Keys.Enter)
                If checkTextbox(TextBox2) = False Then
                    displayMsg("Please fill in the textbox")
                Else
                    If checkTextbox(TextBox2) = True Then
                        TextBox3.Focus()
                    End If
                End If
            Case Else
                'do nothing
        End Select
    End Sub
    Private Sub TextBox3_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TextBox3.KeyPress
        Dim strChar As String
        strChar = e.KeyChar
        Select Case strChar
            Case ChrW(System.Windows.Forms.Keys.Enter)
                If checkTextbox(TextBox3) = False Then
                    displayMsg("Please fill in the textbox")
                Else
                    If checkTextbox(TextBox3) = True Then
                        Button1.Focus()
                    End If
                End If
            Case Else
                'do nothing
        End Select
    End Sub
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        Me.Close()
    End Sub
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        If checkIfAlreadyExists() = False Then
            displayMsg("The Entered Data Already Exists in the Database,Please Enter Another Charge No")
            TextBox1.Focus()
            clearfields()
        Else

            If checkIfAlreadyExists() = True Then
                addCharges()
                displayMsg("The Data has been added into the database")
                clearfields()
                TextBox1.Focus()
            End If
        End If
    End Sub
    Function clearfields()
        TextBox1.Text = ""
        TextBox2.Text = ""
        TextBox3.Text = ""
        TextBox4.Text = ""
    End Function
    Function checkIfAlreadyExists() As Boolean
        getbyname()
        If TextBox4.Text = TextBox1.Text Then
            Return False
        Else
            Return True
        End If
    End Function
    Function getbyname()
        MyConnection.Open()
        MyCommand = New OleDbCommand("SELECT * FROM Charges WHERE ChargeNo ='" & TextBox1.Text & "'", MyConnection)
        Try
            MyReader = MyCommand.ExecuteReader()

            While MyReader.Read
                TextBox4.Text = MyReader("ChargeNo")
            End While
        Catch c As Exception
            MsgBox(c.ToString)
        End Try
        MyConnection.Close()
        MyReader.Close()
    End Function

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        clearfields()
    End Sub
End Class