frm_checkadm.vb

是关于图书管理系统的用vb.net 和access开发的

Imports System.Data.OleDb
Public Class frm_checkAdm


    Dim myConnection As New OleDbConnection("provider=Microsoft.Jet.OLEDB.4.0; Data source=D:\library.mdb")
    Dim myCommand As OleDbCommand
    Dim myReader As OleDbDataReader

    Dim readerNoStr As String = ""
    Dim isbnStr As String = ""
    Dim readerNoArray As Array
    Dim isbnArray As Array
    
    Private Sub admNotxt_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles admNotxt.KeyPress
        If e.KeyChar = ChrW(System.Windows.Forms.Keys.Enter) Then
            passwordtxt.Focus()

        End If
    End Sub

    Private Sub passwordtxt_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles passwordtxt.KeyPress
        If e.KeyChar = ChrW(System.Windows.Forms.Keys.Enter) Then
            If checkValidAdm() Then


                setInfo()

                freeze()

                updateFine()

                MsgBox("completed!")

                Me.Close()
            End If

        End If
    End Sub


    Sub freeze()


        Dim i As Integer

        readerNoArray = readerNoStr.Split(",")

        myConnection.Open()

        For i = 0 To readerNoArray.Length - 2

            Dim tempReaderNo As String
            tempReaderNo = readerNoArray(i)


            myCommand = New OleDbCommand("Update ReaderDetails set Status= 'Freeze' where ReaderNo='" & tempReaderNo & "'", myConnection)

            myCommand.ExecuteNonQuery()

        Next

        myConnection.Close()
        myCommand.Dispose()

    End Sub
    Sub setInfo()



        Try
            myConnection.Open()

            myCommand = New OleDbCommand("select * from RentBook where  Status='Nreturned'and  [DueDate]= #" & Date.Today & "#", myConnection)

            myReader = myCommand.ExecuteReader

            While myReader.Read
                readerNoStr += myReader("ReaderNo").ToString + ","
                isbnStr += myReader("ISBN").ToString + ","

            End While

            myConnection.Close()
            myCommand.Dispose()
            myReader.Close()

        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try





    End Sub
    Sub updateFine()


        Dim i As Integer

        isbnArray = isbnStr.Split(",")

        myConnection.Open()

        For i = 0 To isbnArray.Length - 2

            Dim tempReaderNo As String
            tempReaderNo = readerNoArray(i)


            myCommand = New OleDbCommand("INSERT INTO Fine VALUES( " & _
         "'" & isbnArray(i) & "','" & readerNoArray(i) & "','" & Date.Today.ToShortDateString & _
        " ',Null ,'" & admNotxt.Text & "', 0,'UnPaid','Late Returning')", myConnection)

            myCommand.ExecuteNonQuery()

        Next

        myConnection.Close()
        myCommand.Dispose()

    End Sub
 
    Function checkValidAdm() As Boolean

        Dim admNo As String = ""
        Dim password As String = ""


        myConnection.Open()
        myCommand = New OleDbCommand("select * from Administrator where AdmNo = '" & admNotxt.Text & _
           "'", myConnection)
        myReader = myCommand.ExecuteReader()

        While myReader.Read
            admNo = myReader("AdmNo")
            password = myReader("Password")
        End While

        myConnection.Close()
        myReader.Close()
        myCommand.Dispose()

        If admNo = "" Then
            MsgBox("Invalid Administrator ID!")
        Else

            If password = passwordtxt.Text Then
                Return True
            Else

                MsgBox("Invalid Administrator Password!")
                Return False

            End If
        End If
    End Function
End Class