GF-ERP-SYS-SIU/GF00-ERP-SYS/07.公函與簽呈/公告.vb

Option Strict Off
Imports Microsoft.Office.Interop.Excel.XlUnderlineStyle
Imports Microsoft.Office.Interop.Excel.Constants
Imports Microsoft.Office.Interop.Excel.XlBordersIndex
Imports Microsoft.Office.Interop.Excel.XlLineStyle
Imports Microsoft.Office.Interop.Excel.XlBorderWeight
Imports Microsoft.Office.Interop.Excel.XlThemeFont
Imports Microsoft.Office.Interop.Excel.XlThemeColor
Imports Microsoft.Office.Interop.Excel.XlWindowState
Imports Microsoft.Office.Interop.Excel
Imports System.IO
Public Class 公告
    Dim xlApp As Microsoft.Office.Interop.Excel.Application
    Dim xlBook As Microsoft.Office.Interop.Excel.Workbook
    Dim xlSheet As Microsoft.Office.Interop.Excel.Worksheet
    Dim 位置1 As String
    Dim N2 As Integer : Dim N3 As Integer
    ReadOnly ds As New DataSet : ReadOnly ds1 As New DataSet
    Private Sub 公告_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Me.MdiParent = ICS_ASMS_ERP_SYS : Me.WindowState = 2 : Me.AutoScroll = True

        SQL_讀取公司資料()
        If dr.Read() Then
            公司名稱.Text = dr("公司名稱")
        End If
        conn.Close()
        已核准的營運成本收支單_rb.Checked = True
        作廢的營運成本收支單_rb.Checked = False
        Set_清單1()
        刪除_bt.Enabled = False : 儲存_bt.Enabled = False : 作廢_bt.Enabled = False : 列印_bt.Enabled = False
    End Sub

    Private Sub Set_清單1()
        控制表_dgv.DataSource = Nothing : ds1.Clear()
        控制表_dgv.ColumnHeadersHeightSizeMode = DataGridViewColumnHeadersHeightSizeMode.EnableResizing
        控制表_dgv.ColumnHeadersHeight = 25
        控制表_dgv.AllowUserToAddRows = False
        控制表_dgv.RowTemplate.Height = 30
        If conn.State = ConnectionState.Closed Then : conn.ConnectionString = ConString : conn.Open() : End If
        If 作廢的營運成本收支單_rb.Checked = True And 已核准的營運成本收支單_rb.Checked = False Then
            SQL_通用_控制表清單1("公告")
        ElseIf 作廢的營運成本收支單_rb.Checked = False And 已核准的營運成本收支單_rb.Checked = True Then
            SQL_通用_控制表清單("公告")
        End If
        da.Fill(ds1) : 控制表_dgv.DataSource = ds1.Tables(0) : conn.Close()
        控制表_dgv.Columns(0).FillWeight = 30 : 控制表_dgv.Columns(1).FillWeight = 70 : 控制表_dgv.Columns(2).Visible = False
        控制表_dgv.Columns(3).Visible = False : 控制表_dgv.Columns(4).Visible = False : 控制表_dgv.Columns(5).Visible = False
        控制表_dgv.Columns(6).Visible = False : 控制表_dgv.Columns(7).Visible = False : 控制表_dgv.Columns(8).Visible = False
        控制表_dgv.Columns(9).Visible = False : 控制表_dgv.Columns(10).Visible = False : 控制表_dgv.Columns(11).Visible = False
        控制表_dgv.Columns(12).Visible = False : 控制表_dgv.Columns(13).Visible = False : 控制表_dgv.Columns(14).Visible = False
        控制表_dgv.Columns("開單人").Visible = False

    End Sub
    Private Sub 控制表_dgv_CellClick(ByVal sender As System.Object, ByVal e As System.Windows.Forms.DataGridViewCellEventArgs) Handles 控制表_dgv.CellClick
        If e.RowIndex = -1 Then : Else
            單號_tb.Text = 控制表_dgv(2, e.RowIndex).Value.ToString
            Dim dateString As String = 控制表_dgv(0, e.RowIndex).Value.ToString
            Dim dateParts() As String = dateString.Split("/"c)
            Dim year As Integer = Integer.Parse(dateParts(0)) + 1911 ' 將民國年轉換為西元年
            Dim month As Integer = Integer.Parse(dateParts(1))
            Dim day As Integer = Integer.Parse(dateParts(2))
            Dim dateTime As New DateTime(year, month, day)
            選擇日期_dtp.Value = dateTime
            選擇日期_dtp.CustomFormat = "yyyy/MM/dd"
            選擇日期_dtp.Format = DateTimePickerFormat.Custom
            檔案名稱_tb.Text = 控制表_dgv(1, e.RowIndex).Value.ToString
            主旨_tb.Text = 控制表_dgv(3, e.RowIndex).Value.ToString
            說明_rtb.Text = 控制表_dgv(4, e.RowIndex).Value.ToString
            擬辦_tb.Text = 控制表_dgv(5, e.RowIndex).Value.ToString
            ComboBox1.Text = 控制表_dgv(6, e.RowIndex).Value.ToString
            ComboBox2.Text = 控制表_dgv(7, e.RowIndex).Value.ToString
            ComboBox3.Text = 控制表_dgv(8, e.RowIndex).Value.ToString
            ComboBox4.Text = 控制表_dgv(9, e.RowIndex).Value.ToString
            ComboBox5.Text = 控制表_dgv(10, e.RowIndex).Value.ToString
            ComboBox6.Text = 控制表_dgv(11, e.RowIndex).Value.ToString
            ComboBox7.Text = 控制表_dgv(12, e.RowIndex).Value.ToString
            ComboBox7.Text = 控制表_dgv(12, e.RowIndex).Value.ToString
            開單人_tb.Text = 控制表_dgv("開單人", e.RowIndex).Value.ToString

            If 登入人級別 <> "00" Then
                If 控制表_dgv(14, e.RowIndex).Value = True Then
                    刪除_bt.Enabled = False : 儲存_bt.Enabled = False : 作廢_bt.Enabled = False : 列印_bt.Enabled = True : 新增_bt.Enabled = True
                ElseIf 控制表_dgv(13, e.RowIndex).Value = True And 控制表_dgv(14, e.RowIndex).Value = False Then
                    刪除_bt.Enabled = False : 儲存_bt.Enabled = False : 作廢_bt.Enabled = True : 列印_bt.Enabled = True : 新增_bt.Enabled = True
                ElseIf 控制表_dgv(13, e.RowIndex).Value = False And 控制表_dgv(14, e.RowIndex).Value = False Then
                    刪除_bt.Enabled = True : 儲存_bt.Enabled = True : 作廢_bt.Enabled = True : 列印_bt.Enabled = True : 新增_bt.Enabled = True
                End If
            Else
                刪除_bt.Enabled = True : 儲存_bt.Enabled = True : 作廢_bt.Enabled = True : 列印_bt.Enabled = True : 新增_bt.Enabled = True
            End If
        End If
    End Sub
    Private Sub 查詢_tb_Click(sender As Object, e As EventArgs) Handles 查詢_tb.Click
        PA56 = InputBox("請輸入要查詢的單號資料。") : Set_清單1() : PA56 = ""
    End Sub
    Private Sub 檔案名稱_tb_KeyPress(sender As Object, e As KeyPressEventArgs) Handles 檔案名稱_tb.KeyPress
        ' 允许字母、数字和空格，禁止其他字符
        If Not Char.IsLetterOrDigit(e.KeyChar) AndAlso Not Char.IsWhiteSpace(e.KeyChar) Then
            e.Handled = True
        End If
    End Sub
    Private Sub 新增_bt_Click(sender As Object, e As EventArgs) Handles 新增_bt.Click
        單號_tb.Text = "" : 檔案名稱_tb.Text = "" : 主旨_tb.Text = "" : 說明_rtb.Text = "" : 擬辦_tb.Text = ""
        ComboBox1.Text = "" : ComboBox2.Text = "" : ComboBox3.Text = "" : ComboBox4.Text = ""
        ComboBox5.Text = "" : ComboBox6.Text = "" : ComboBox7.Text = "" : 開單人_tb.Text = gUserName
        Dim NUM1 As Integer
        Dim dat1 As String
        Dim selectedDate As DateTime = 選擇日期_dtp.Value
        Dim taiwanYear As Integer = selectedDate.Year - 1911
        Dim str As String = String.Format("{0}{1:00}{2:00}", taiwanYear, selectedDate.Month, selectedDate.Day)
        PA1 = String.Format("{0}/{1:00}/{2:00}", taiwanYear, selectedDate.Month, selectedDate.Day)

        SQL_通用_查詢第一筆單號()
        If dr.Read() Then : 單號_tb.Text = dr("流水號").ToString : Else : 單號_tb.Text = str & "00" : End If

        dat1 = 單號_tb.Text.Substring(0, 7)
        If dat1 <> str Then : NUM1 = 1 : Else : NUM1 = Double.Parse(單號_tb.Text.Substring(7, 2)) + 1 : End If

        If NUM1 < 10 Then : 單號_tb.Text = str & "0" & NUM1
        ElseIf NUM1 > 9 Then : 單號_tb.Text = str & NUM1
        End If

        PA = 單號_tb.Text
        SQL_通用_新增一筆公函控制表("公告") : conn.Close()
        刪除_bt.Enabled = True : 儲存_bt.Enabled = True : 作廢_bt.Enabled = False : 列印_bt.Enabled = False : 新增_bt.Enabled = False
        'ComboBox1.SelectedIndex = 2
        'ComboBox2.SelectedIndex = 3
        'ComboBox3.SelectedIndex = 7
        'ComboBox4.SelectedIndex = 8
    End Sub
    Private Sub 刪除_bt_Click(sender As Object, e As EventArgs) Handles 刪除_bt.Click
        SQL_通用_控制表刪除(單號_tb.Text) : conn.Close() : MsgBox("刪除成功!!")
        單號_tb.Text = "" : 檔案名稱_tb.Text = "" : 主旨_tb.Text = "" : 說明_rtb.Text = "" : 擬辦_tb.Text = ""
        ComboBox1.Text = "" : ComboBox2.Text = "" : ComboBox3.Text = "" : ComboBox4.Text = "" : 開單人_tb.Text = ""
        ComboBox5.Text = "" : ComboBox6.Text = "" : ComboBox7.Text = "" : Set_清單1()
        刪除_bt.Enabled = False : 儲存_bt.Enabled = False : 作廢_bt.Enabled = False : 列印_bt.Enabled = False : 新增_bt.Enabled = True
    End Sub

    Private Sub 儲存_bt_Click(sender As Object, e As EventArgs) Handles 儲存_bt.Click
        If 開單人_tb.Text = gUserName Or 登入人級別 = "00" Then
            SQL_通用_控制表修改(檔案名稱_tb.Text, 主旨_tb.Text, 說明_rtb.Text, 擬辦_tb.Text, ComboBox1.Text, ComboBox2.Text, ComboBox3.Text, ComboBox4.Text,
                     ComboBox5.Text, ComboBox6.Text, ComboBox7.Text, 單號_tb.Text, "公告") : conn.Close() : MsgBox("儲存成功!!") : Set_清單1()
            If 登入人級別 <> "00" Then
                刪除_bt.Enabled = True : 儲存_bt.Enabled = True : 作廢_bt.Enabled = True : 列印_bt.Enabled = True : 新增_bt.Enabled = True
            End If
        Else
            MsgBox("請確認開單人是否為本人")
        End If
    End Sub

    Private Sub 作廢_bt_Click(sender As Object, e As EventArgs) Handles 作廢_bt.Click
        SQL_通用_控制表作廢(單號_tb.Text, "公告") : conn.Close() : MsgBox("作廢成功!!") : Set_清單1()
        刪除_bt.Enabled = False : 儲存_bt.Enabled = False : 作廢_bt.Enabled = False : 列印_bt.Enabled = True
    End Sub
    Private Sub 作廢的營運成本收支單_rb_CheckedChanged(sender As Object, e As EventArgs) Handles 作廢的營運成本收支單_rb.Click
        作廢的營運成本收支單_rb.Checked = True : 已核准的營運成本收支單_rb.Checked = False
        Set_清單1()
    End Sub
    Private Sub 已核准的營運成本收支單_rb_CheckedChanged(sender As Object, e As EventArgs) Handles 已核准的營運成本收支單_rb.Click
        作廢的營運成本收支單_rb.Checked = False : 已核准的營運成本收支單_rb.Checked = True
        Set_清單1()
    End Sub
    Private Sub 查詢_tb_MouseEnter(sender As Object, e As EventArgs) Handles 查詢_tb.MouseEnter
        ToolTip1.SetToolTip(Me.查詢_tb, "關鍵字搜尋")
    End Sub
    Private Sub 新增_bt_MouseEnter(sender As Object, e As EventArgs) Handles 新增_bt.MouseEnter
        ToolTip1.SetToolTip(Me.新增_bt, "新增")
    End Sub
    Private Sub 確認新增_bt_MouseEnter(sender As Object, e As EventArgs) Handles 儲存_bt.MouseEnter
        ToolTip1.SetToolTip(Me.儲存_bt, "儲存")
    End Sub
    Private Sub 修改_bt_MouseEnter(sender As Object, e As EventArgs) Handles 作廢_bt.MouseEnter
        ToolTip1.SetToolTip(Me.作廢_bt, "作廢")
    End Sub
    Private Sub 刪除_bt_MouseEnter(sender As Object, e As EventArgs) Handles 刪除_bt.MouseEnter
        ToolTip1.SetToolTip(Me.刪除_bt, "刪除")
    End Sub
    Private Sub 匯出EXCEL_bt_MouseEnter(sender As Object, e As EventArgs) Handles 列印_bt.MouseEnter
        ToolTip1.SetToolTip(Me.列印_bt, "匯出PDF")
    End Sub
    Private Sub 字體_NUD_ValueChanged(sender As Object, e As EventArgs) Handles 字體_NUD.ValueChanged
        主旨_tb.Font = New System.Drawing.Font("微軟正黑體", 字體_NUD.Value)
        說明_rtb.Font = New System.Drawing.Font("微軟正黑體", 字體_NUD.Value)
        擬辦_tb.Font = New System.Drawing.Font("微軟正黑體", 字體_NUD.Value)
    End Sub
    Private Sub 列印_bt_Click(sender As Object, e As EventArgs) Handles 列印_bt.Click
        SQL_通用_控制表鎖定(單號_tb.Text, "公告")
        If 登入人級別 <> "00" Then
            刪除_bt.Enabled = False : 儲存_bt.Enabled = False : 作廢_bt.Enabled = True : 列印_bt.Enabled = True : 新增_bt.Enabled = True
        End If
        Set_清單1()
        xlApp = CType(CreateObject("Excel.Application"), Microsoft.Office.Interop.Excel.Application) : xlApp.Visible = True : xlApp.DisplayAlerts = True
        xlApp.Application.WindowState = xlMaximized : xlBook = xlApp.Workbooks.Add : xlSheet = NewMethod(xlBook) : xlBook.Activate() : xlSheet.Activate()
        xlSheet.Cells(1, 1) = "公告"
        xlSheet.Cells(2, 1) = "主旨："


        xlSheet.Cells(2, 2) = 主旨_tb.Text : xlSheet.Cells(2, 3) = 主旨_tb.Text
        xlSheet.Cells(3, 1) = "說明："
        Dim lines As New List(Of String)()
        Dim text As String = 說明_rtb.Text
        lines.Clear()
        ' 使用 Graphics.MeasureString 测量文本的宽度
        Using g As Graphics = CreateGraphics()
            Dim currentLine As String = ""

            For Each c As Char In text
                If c = ControlChars.Lf Then
                    ' 如果遇到换行符号，添加一个新的段落
                    lines.Add(currentLine)
                    currentLine = ""
                Else
                    currentLine += c

                    ' 计算当前行的宽度
                    Dim width As Integer = TextRenderer.MeasureText(currentLine, 說明_rtb.Font).Width

                    ' 当宽度接近 RichTextBox 的宽度时，添加一个分段符号
                    If width >= 450 Then
                        lines.Add(currentLine)
                        currentLine = ""
                    End If
                End If
            Next

            ' 如果最后一行没有被添加，添加它
            If currentLine <> "" Then
                lines.Add(currentLine)
            End If
        End Using
        For i As Integer = 0 To lines.Count - 1
            字串處理(lines(i))
            lines(i) = 已處理字串
        Next

        For i = 0 To lines.Count - 1
            xlSheet.Cells(3 + i, 2) = lines(i) : xlSheet.Cells(3 + i, 3) = lines(i)
            N2 = i + 3
        Next

        BB(xlApp, xlSheet)

        xlApp.Sheets(2).Delete : xlSheet.PageSetup.PrintArea = ""
        Dim pdfFolderPath As String = Path.Combine(System.Windows.Forms.Application.StartupPath, "pdf")
        If Not Directory.Exists(pdfFolderPath) Then
            Directory.CreateDirectory(pdfFolderPath)
        End If
        Dim pdfFilePath As String = Path.Combine(pdfFolderPath, 檔案名稱_tb.Text & ".pdf")
        xlBook.Sheets(1).ExportAsFixedFormat(XlFixedFormatType.xlTypePDF, pdfFilePath, XlFixedFormatQuality.xlQualityStandard, True)
        xlApp.Cells.Select() : xlApp.Application.WindowState = xlMinimized : xlBook.Close(False)
        Runtime.InteropServices.Marshal.ReleaseComObject(xlSheet)
        Runtime.InteropServices.Marshal.ReleaseComObject(xlBook)
        Runtime.InteropServices.Marshal.ReleaseComObject(xlApp)
        xlApp.Quit() : xlSheet = Nothing : xlBook = Nothing : xlApp = Nothing : GC.Collect()
        Try
            Dim chromePath As String = "C:\Program Files\Google\Chrome\Application\chrome.exe"
            If System.IO.File.Exists(chromePath) Then
                Dim process As New Process()
                process.StartInfo.FileName = "chrome"
                process.StartInfo.Arguments = """" & pdfFilePath & """"
                process.Start()
            Else : Dim edgePath As String = "C:\Program Files (x86)\Microsoft\Edge\Application\msedge.exe"
                If System.IO.File.Exists(edgePath) Then
                    Dim process As New Process()
                    process.StartInfo.FileName = "msedge"
                    process.StartInfo.Arguments = """" & pdfFilePath & """"
                    process.Start()
                Else
                    Process.Start(pdfFilePath)
                End If
            End If
        Catch ex As Exception
            MsgBox("以存檔至桌面 。" & vbCrLf & "檔案名稱：" & 檔案名稱_tb.Text & ".pdf")
        End Try
    End Sub
    Private Shared Function NewMethod(xlBook As Microsoft.Office.Interop.Excel.Workbook) As Microsoft.Office.Interop.Excel.Worksheet
        Return CType(xlBook.Worksheets.Add, Microsoft.Office.Interop.Excel.Worksheet)
    End Function
    Private Sub BB(ByVal myExcel As Microsoft.Office.Interop.Excel.Application, ByVal xlSheet As Microsoft.Office.Interop.Excel.Worksheet)
        xlSheet.Cells.Select()
        With myExcel.Selection.Font
            .Name = "標楷體"
            .Size = 16
            .Strikethrough = False
            .Superscript = False
            .Subscript = False
            .OutlineFont = False
            .Shadow = False
            .Underline = xlUnderlineStyleNone
            .ThemeColor = xlThemeColorLight1
            .TintAndShade = 0
            .ThemeFont = xlThemeFontNone
        End With
        xlSheet.Rows("1:1").Select
        With myExcel.Selection.Font
            .Name = "標楷體"
            .Size = 18
            .Strikethrough = False
            .Superscript = False
            .Subscript = False
            .OutlineFont = False
            .Shadow = False
            .Underline = xlUnderlineStyleNone
            .ThemeColor = xlThemeColorLight1
            .TintAndShade = 0
            .ThemeFont = xlThemeFontNone
        End With
        xlSheet.Columns("A:A").ColumnWidth = 8
        xlSheet.Columns("B:B").ColumnWidth = 85
        xlSheet.Columns("C:C").ColumnWidth = 85


        xlSheet.Range("A1:B1").Select()
        With myExcel.Selection
            .HorizontalAlignment = xlCenter
            .VerticalAlignment = xlCenter
            .WrapText = False
            .Orientation = 0
            .AddIndent = False
            .IndentLevel = 0
            .ShrinkToFit = False
            .ReadingOrder = xlContext
            .MergeCells = False
        End With
        myExcel.Selection.Merge

        xlSheet.Range("A2").Select()
        With myExcel.Selection
            .HorizontalAlignment = xlLeft
            .VerticalAlignment = xlTop
            .WrapText = False
            .Orientation = 0
            .AddIndent = False
            .IndentLevel = 0
            .ShrinkToFit = False
            .ReadingOrder = xlContext
            .MergeCells = False
        End With
        xlSheet.Range("A3").Select()
        With myExcel.Selection
            .HorizontalAlignment = xlLeft
            .VerticalAlignment = xlTop
            .WrapText = False
            .Orientation = 0
            .AddIndent = False
            .IndentLevel = 0
            .ShrinkToFit = False
            .ReadingOrder = xlContext
            .MergeCells = False
        End With
        xlSheet.Range("B2").Select()
        With myExcel.Selection
            .HorizontalAlignment = xlLeft
            .VerticalAlignment = xlTop
            .WrapText = True
            .Orientation = 0
            .AddIndent = False
            .IndentLevel = 0
            .ShrinkToFit = False
            .ReadingOrder = xlContext
            .MergeCells = False
        End With

        For i = 3 To N2
            xlSheet.Range("B" & i).Select()
            With myExcel.Selection
                .HorizontalAlignment = xlLeft
                .VerticalAlignment = xlTop
                .WrapText = True
                .Orientation = 0
                .AddIndent = False
                .IndentLevel = 0
                .ShrinkToFit = False
                .ReadingOrder = xlContext
                .MergeCells = False
            End With
        Next


        For i = 1 To N2
            xlSheet.Rows(i & ":" & i).Select
            xlSheet.Rows(i & ":" & i).EntireRow.AutoFit
        Next
        xlSheet.Columns("C").Select
        myExcel.Selection.EntireColumn.Hidden = True

        For i = 1 To N2
            xlSheet.Rows(i).RowHeight = xlSheet.Rows(i).RowHeight + 5
        Next i
        Dim tt As String
        If 隱藏最後排日期_cb.Checked = True Then
            Dim selectedDate As DateTime = 選擇日期_dtp.Value
            Dim taiwanYear As Integer = selectedDate.Year - 1911
            tt = "中華民國" & taiwanYear & "年" & selectedDate.Month & "月" & selectedDate.Day & "日"
        Else
            tt = ""
        End If

        myExcel.Application.PrintCommunication = False
        With myExcel.ActiveSheet.PageSetup
            .PrintTitleRows = ""
            .PrintTitleColumns = ""
        End With
        myExcel.Application.PrintCommunication = True
        myExcel.ActiveSheet.PageSetup.PrintArea = ""
        myExcel.Application.PrintCommunication = False
        With myExcel.ActiveSheet.PageSetup
            .LeftHeader = ""
            .CenterHeader = ""
            .RightHeader = ""
            .LeftFooter = ""
            .CenterFooter = tt
            .RightFooter = ""
            .LeftMargin = myExcel.Application.InchesToPoints(0.25)
            .RightMargin = myExcel.Application.InchesToPoints(0.25)
            .TopMargin = myExcel.Application.InchesToPoints(0.75)
            .BottomMargin = myExcel.Application.InchesToPoints(0.75)
            .HeaderMargin = myExcel.Application.InchesToPoints(0.3)
            .FooterMargin = myExcel.Application.InchesToPoints(0.3)
            .PrintHeadings = False
            .PrintGridlines = False
            .CenterHorizontally = False
            .CenterVertically = False
            .Draft = False
            .FirstPageNumber = xlAutomatic
            .BlackAndWhite = False
            .Zoom = False
            .FitToPagesWide = 1
            .FitToPagesTall = 0
            .OddAndEvenPagesHeaderFooter = False
            .DifferentFirstPageHeaderFooter = False
            .ScaleWithDocHeaderFooter = True
            .AlignMarginsHeaderFooter = True
            .EvenPage.LeftHeader.Text = ""
            .EvenPage.CenterHeader.Text = ""
            .EvenPage.RightHeader.Text = ""
            .EvenPage.LeftFooter.Text = ""
            .EvenPage.CenterFooter.Text = ""
            .EvenPage.RightFooter.Text = ""
            .FirstPage.LeftHeader.Text = ""
            .FirstPage.CenterHeader.Text = ""
            .FirstPage.RightHeader.Text = ""
            .FirstPage.LeftFooter.Text = ""
            .FirstPage.CenterFooter.Text = ""
            .FirstPage.RightFooter.Text = ""
        End With
        myExcel.Application.PrintCommunication = True
    End Sub
End Class