transaction.vb

图书管理系统最新的

        Try

            i = dg_books.CurrentRowIndex

            If rd_issue.Checked = True Then
                txt_bookid.Text = dg_books.Item(i, 0)
                txt_booktitle.Text = dg_books.Item(i, 1)
            Else
                txt_sid.Text = dg_books.Item(i, 0)
                txt_sname.Text = dg_books.Item(i, 1)
                txt_branch.Text = dg_books.Item(i, 2)
                txt_bookid.Text = dg_books.Item(i, 3)
                txt_booktitle.Text = dg_books.Item(i, 4)
                txt_issue.Text = Format(dg_books.Item(i, 5), "dd-MM-yyyy")

            End If

            Cmb_desc.SelectedIndex = 0

        Catch err As System.Exception

        End Try
    End Sub


    Private Sub txt_sid_KeyPress(ByVal sender As Object, ByVal e As System.Windows.Forms.KeyPressEventArgs) Handles txt_sid.KeyPress


        If Asc(e.KeyChar) = Keys.Enter Then

            fill_data()

        End If

    End Sub

    Sub cleardatabind()
        txt_sid.DataBindings.Clear()
        txt_sname.DataBindings.Clear()
        txt_branch.DataBindings.Clear()
        txt_bookid.DataBindings.Clear()
        txt_booktitle.DataBindings.Clear()
        txt_issue.DataBindings.Clear()
    End Sub


    Sub clearfields()
        txt_sid.Clear()
        txt_sname.Clear()
        txt_branch.Clear()
        txt_bookid.Clear()
        txt_booktitle.Clear()
        txt_sid.Focus()
    End Sub

    Private Sub dg_books_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles dg_books.Click

        get_from_grid()

        If rd_return.Checked = True Then
            cal_fine()
        End If

    End Sub

    Private Sub dg_books_CurrentCellChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles dg_books.CurrentCellChanged

        get_from_grid()

        If rd_return.Checked = True Then
            cal_fine()
        End If

    End Sub


    Private Function check_if_issued() As Short

        Dim bid As String

        Try

            cmd = New SqlCommand
            With cmd
                .Connection = cn
                .CommandText = "select Book_Id from trans where S_id='" & txt_sid.Text & "'"
            End With

            ' storing fine charge in a variable
            bid = CType(cmd.ExecuteScalar, String)

            If bid <> "" Then
                Return 1
            Else
                Return 0
            End If


        Catch ex As SqlException
            MessageBox.Show(ex.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error)
            Me.Close()

        Finally

            cmd = Nothing

        End Try



    End Function


    Private Sub btn_new_Click(ByVal sender As System.Object, ByVal e As System.EventArgs)
        clearfields()
    End Sub


    Private Sub btn_return_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btn_return.Click

        Try

            If txt_sid.Text <> "" AndAlso txt_sname.Text <> "" AndAlso txt_branch.Text <> "" _
                 AndAlso txt_bookid.Text <> "" AndAlso txt_booktitle.Text <> "" Then

                'deleting the record
                cmd = New SqlCommand
                cmd.Connection = cn
                cmd.CommandText = "delete from trans where S_Id='" & txt_sid.Text & "'"
                i = cmd.ExecuteNonQuery()

                If i > 0 Then

                    If lbl_fine_disp.Text <> "0" Then

                        cmd = New SqlCommand
                        cmd.Connection = cn
                        cmd.CommandText = "insert into fine_info values('" & txt_sid.Text & "'," & Val(lbl_fine_disp.Text) & ",'" & Cmb_desc.Text & "','" & Date.Today.ToShortDateString & "') "
                        cmd.ExecuteNonQuery()

                    End If


                    MessageBox.Show("Book successfully returned.", "LMS", MessageBoxButtons.OK, MessageBoxIcon.Information)
                    return_fillgrid()
                    clearfields()
                    lbl_fine_disp.Text = ""
                    Cmb_desc.SelectedIndex = 0
                    txt_issue.Clear()

                Else
                    MessageBox.Show("Book is not present.", "LMS", MessageBoxButtons.OK, MessageBoxIcon.Stop)
                    txt_bookid.Focus()
                End If

            Else

                MessageBox.Show("All fields are mandatory to fill." & vbNewLine & "Enter the student ID or select from the list shown by clicking on it.", "LMS", MessageBoxButtons.OK, MessageBoxIcon.Warning)
                clearfields()
                txt_sid.Focus()

            End If


        Catch ex As SqlException
            MessageBox.Show(ex.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error)

        Catch err As System.Exception
            MessageBox.Show(err.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error)

        Finally

            cmd = Nothing

        End Try

    End Sub


    Sub cal_fine()

        Try
            If txt_sid.Text <> "" AndAlso txt_sname.Text <> "" AndAlso txt_branch.Text <> "" _
                         AndAlso txt_bookid.Text <> "" AndAlso txt_booktitle.Text <> "" Then

                If Cmb_desc.SelectedItem = "Late fine" Then
                    'calculating fine

                    cmd = New SqlCommand
                    With cmd
                        .Connection = cn
                        .CommandText = "select issue_date from trans where S_Id='" & txt_sid.Text & "'"
                    End With

                    ' storing fine charge in a variable
                    d = CType(cmd.ExecuteScalar, Date)

                    If (DateDiff(DateInterval.Day, d, Date.Today) - 7) > 0 Then
                        lbl_fine_disp.Text = f_charge * (DateDiff(DateInterval.Day, d, Date.Today) - 7)
                    Else
                        lbl_fine_disp.Text = "0"
                    End If

                Else 'book lost

                    cmd = New SqlCommand
                    With cmd
                        .Connection = cn
                        .CommandText = "select price from book_info where Book_Id='" & txt_bookid.Text & "'"
                    End With

                    ' storing fine charge in a variable
                    f = CType(cmd.ExecuteScalar, Integer)

                    lbl_fine_disp.Text = f


                End If

            End If



        Catch ex As SqlException
            MessageBox.Show(ex.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error)

        Catch err As System.Exception
            MessageBox.Show(err.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error)

        Finally

            'dereferencing objects
            da = Nothing
            ds = Nothing
            dv = Nothing

        End Try
    End Sub

    Private Sub Cmb_desc_SelectedIndexChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Cmb_desc.SelectedIndexChanged
        cal_fine()
    End Sub

    Private Sub transaction_Closing(ByVal sender As Object, ByVal e As System.ComponentModel.CancelEventArgs) Handles MyBase.Closing
        cn.Close()
    End Sub

    Private Sub txt_sid_LostFocus(ByVal sender As Object, ByVal e As System.EventArgs) Handles txt_sid.LostFocus

        If txt_sid.Text <> "" Then
            fill_data()
        End If

    End Sub


    Sub fill_data()

        Try

            cleardatabind()

            da = New SqlDataAdapter("select Name,Branch from stud_info where S_Id='" & txt_sid.Text & "'", cn)
            ds = New DataSet
            da.Fill(ds, "stud_info")

            If ds.Tables(0).Rows.Count > 0 Then

                dv = New DataView(ds.Tables(0))

                txt_sname.DataBindings.Add("Text", dv, "Name")
                txt_branch.DataBindings.Add("Text", dv, "Branch")

                If rd_issue.Checked = False Then

                    da = New SqlDataAdapter("select b1.Book_Id,b1.Title,t1.issue_date from book_info b1,trans t1 where b1.Book_Id=(select t2.Book_id from trans t2 where t2.S_Id='" & txt_sid.Text & "') and t1.Book_Id=b1.Book_Id", cn)
                    ds = New DataSet
                    da.Fill(ds, "stud_info")
                    dv = New DataView(ds.Tables(0))

                    If ds.Tables(0).Rows.Count > 0 Then
                        txt_bookid.DataBindings.Add("Text", dv, "Book_Id")
                        txt_booktitle.DataBindings.Add("Text", dv, "Title")
                        txt_issue.DataBindings.Add("Text", dv, "issue_date")

                        'displaying fine
                        cal_fine()
                    Else
                        txt_sname.Clear()
                        txt_branch.Clear()
                        txt_bookid.Clear()
                        txt_booktitle.Clear()
                    End If


                End If

            Else

                txt_sname.Clear()
                txt_branch.Clear()
                txt_bookid.Clear()
                txt_booktitle.Clear()

            End If


        Catch ex As SqlException
            MessageBox.Show(ex.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error)

        Catch err As System.Exception
            MessageBox.Show(err.Message, "Exception", MessageBoxButtons.OK, MessageBoxIcon.Error)

        Finally

            'dereferencing objects
            da = Nothing
            ds = Nothing
            dv = Nothing

            Cmb_desc.SelectedIndex = 0

        End Try


    End Sub


End Class