frm_returnbook.vb

基于VBNET编写的图书馆管理系统

        '
        Me.Label3.AutoSize = True
        Me.Label3.Location = New System.Drawing.Point(10, 95)
        Me.Label3.Name = "Label3"
        Me.Label3.Size = New System.Drawing.Size(53, 12)
        Me.Label3.TabIndex = 2
        Me.Label3.Text = "书籍名称"
        '
        'Label2
        '
        Me.Label2.AutoSize = True
        Me.Label2.Location = New System.Drawing.Point(10, 60)
        Me.Label2.Name = "Label2"
        Me.Label2.Size = New System.Drawing.Size(53, 12)
        Me.Label2.TabIndex = 1
        Me.Label2.Text = "书籍编号"
        '
        'Label1
        '
        Me.Label1.AutoSize = True
        Me.Label1.Location = New System.Drawing.Point(22, 26)
        Me.Label1.Name = "Label1"
        Me.Label1.Size = New System.Drawing.Size(41, 12)
        Me.Label1.TabIndex = 0
        Me.Label1.Text = "借阅号"
        '
        'BtnReturn
        '
        Me.BtnReturn.Location = New System.Drawing.Point(42, 231)
        Me.BtnReturn.Name = "BtnReturn"
        Me.BtnReturn.Size = New System.Drawing.Size(91, 25)
        Me.BtnReturn.TabIndex = 1
        Me.BtnReturn.Text = "归还"
        '
        'Button2
        '
        Me.Button2.Location = New System.Drawing.Point(244, 231)
        Me.Button2.Name = "Button2"
        Me.Button2.Size = New System.Drawing.Size(80, 25)
        Me.Button2.TabIndex = 2
        Me.Button2.Text = "重置"
        '
        'Button3
        '
        Me.Button3.Location = New System.Drawing.Point(416, 231)
        Me.Button3.Name = "Button3"
        Me.Button3.Size = New System.Drawing.Size(81, 25)
        Me.Button3.TabIndex = 3
        Me.Button3.Text = "关闭"
        '
        'TextBox10
        '
        Me.TextBox10.Location = New System.Drawing.Point(854, 112)
        Me.TextBox10.Name = "TextBox10"
        Me.TextBox10.Size = New System.Drawing.Size(120, 21)
        Me.TextBox10.TabIndex = 4
        Me.TextBox10.Visible = False
        '
        'frm_ReturnBook
        '
        Me.AutoScaleBaseSize = New System.Drawing.Size(6, 14)
        Me.ClientSize = New System.Drawing.Size(550, 268)
        Me.Controls.Add(Me.TextBox10)
        Me.Controls.Add(Me.Button3)
        Me.Controls.Add(Me.Button2)
        Me.Controls.Add(Me.BtnReturn)
        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_ReturnBook"
        Me.StartPosition = System.Windows.Forms.FormStartPosition.CenterScreen
        Me.Text = "归还书籍"
        Me.GroupBox1.ResumeLayout(False)
        Me.GroupBox1.PerformLayout()
        Me.ResumeLayout(False)
        Me.PerformLayout()

    End Sub

#End Region




    Sub clearFields()
        TxtIssueNo.Text = ""
        TxtSN.Text = ""
        TxtBookName.Text = ""
        TxtAuthorName.Text = ""
        TxtReaderNo.Text = ""
        TxtReaderName.Text = ""
        TxtIssueDate.Text = ""
        TxtOverDueDate.Text = ""
        TxtChargeType.Text = ""
    End Sub

    Sub loadIssuedBook()
        MyConnection.Open()
        MyCommand = New OleDbCommand("SELECT * FROM IssueBook WHERE IssueNo ='" & TxtIssueNo.Text & "'", MyConnection)
        MyReader = MyCommand.ExecuteReader()
        While MyReader.Read
            TxtSN.Text = MyReader("SN")
            TxtBookName.Text = MyReader("BookName")
            TxtAuthorName.Text = MyReader("AuthorName")
            TxtReaderNo.Text = MyReader("ReaderNo")
            TxtReaderName.Text = MyReader("ReaderName")
            TxtIssueDate.Text = MyReader("idate")
            TxtOverDueDate.Text = MyReader("ddate")
            TxtChargeType.Text = MyReader("itype")
        End While
        MyConnection.Close()
        MyReader.Close()
        MyCommand.dispose()
    End Sub

    Function checkIfAlreadyExists() As Boolean
        MyConnection.Open()
        MyCommand = New OleDbCommand("SELECT * FROM IssueBook WHERE IssueNo ='" & TxtIssueNo.Text & "'", MyConnection)
        Try
            MyReader = MyCommand.ExecuteReader()
            While MyReader.Read
                TextBox10.Text = MyReader("IssueNo")
            End While
        Catch c As Exception
            MsgBox(c.ToString)
        End Try

        MyConnection.Close()
        MyReader.Close()
        MyCommand.dispose()
        If TxtIssueNo.Text = TextBox10.Text Then
            Return True
        Else
            If TxtIssueNo.Text <> TextBox10.Text Then
                Return False
            End If
        End If
    End Function

    Sub updateReaderIssueTag()
        Dim CurrentIssueTag As String
        Dim CurrentIssueTagUsed As String
        Dim itag As Integer
        Dim itagused As Integer
        CurrentIssueTag = getCurrentReaderIssueTag()
        CurrentIssueTagUsed = getCurrentReaderTagUsed()
        itag = CInt(CurrentIssueTag)
        itagused = CInt(CurrentIssueTagUsed)

        itag = itag + 1
        itagused = itagused - 1

        CurrentIssueTag = itag.ToString
        CurrentIssueTagUsed = itagused.ToString

        MyConnection.Open()
        MyCommand = New OleDbCommand("UPDATE ReaderDetails SET IssueTag ='" & CurrentIssueTag & "',IssueTagUsed = '" & CurrentIssueTagUsed & "' WHERE ReaderNo = '" & TxtReaderNo.Text & "'", MyConnection)
        Try
            MyCommand.ExecuteNonQuery()
        Catch c As Exception
            MsgBox(c.ToString)
        End Try
        MyConnection.Close()
        MyCommand.dispose()
    End Sub
    Sub updateBookStatus()
        Dim myStatus As String
        myStatus = "OK"
        MyConnection.Open()
        MyCommand = New OleDbCommand("UPDATE BookDetails SET BookStatus ='" & myStatus & "' WHERE SN = '" & TxtSN.Text & "'", MyConnection)
        Try
            MyCommand.ExecuteNonQuery()
        Catch c As Exception
            MsgBox(c.ToString)
        End Try
        MyConnection.Close()
        MyCommand.dispose()
    End Sub

    Function getCurrentReaderIssueTag() As String
        Dim myTag As String
        MyConnection.Open()
        MyCommand = New OleDbCommand("SELECT * FROM ReaderDetails WHERE ReaderNo = '" & TxtReaderNo.Text & "'", MyConnection)
        MyReader = MyCommand.ExecuteReader()
        While MyReader.Read
            myTag = MyReader("IssueTag")
        End While
        MyConnection.Close()
        MyReader.Close()
        MyCommand.dispose()
        Return myTag
    End Function
    Function getCurrentReaderTagUsed() As String
        Dim myTag As String
        MyConnection.Open()
        MyCommand = New OleDbCommand("SELECT * FROM ReaderDetails WHERE ReaderNo = '" & TxtReaderNo.Text & "'", MyConnection)
        MyReader = MyCommand.ExecuteReader()
        While MyReader.Read
            myTag = MyReader("IssueTagUsed")
        End While
        MyConnection.Close()
        MyReader.Close()
        MyCommand.dispose()
        Return myTag
    End Function




    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        Me.Close()
    End Sub

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


    Private Sub TxtIssueNo_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles TxtIssueNo.KeyPress
        Dim strChar As String
        strChar = e.KeyChar
        Select Case strChar
            Case ChrW(System.Windows.Forms.Keys.Enter)
                If TxtIssueNo.Text = "" Or checkIfAlreadyExists() = False Then
                    MsgBox("请输入有效的借阅号", MsgBoxStyle.Information, "图书馆管理系统")
                Else
                    If TxtIssueNo.Text <> "" And checkIfAlreadyExists() = True Then
                        loadIssuedBook()
                        BtnReturn.Focus()
                    End If
                End If
            Case Else
        End Select
    End Sub

    Private Sub BtnReturn_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles BtnReturn.Click
        updateReaderIssueTag()
        updateBookStatus()
        MsgBox("成功归还书籍", MsgBoxStyle.Information, "图书馆管理系统")
        clearFields()
    End Sub

    Private Sub TextBox3_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TxtBookName.TextChanged

    End Sub

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

    End Sub
End Class