winform 数据库资料导出Excel方法（适用于资料数据较多加载慢，不用呈现至DatagridView）

 Private Sub savefile(ByVal dgv2 As DataTable)

        Dim app As Object = CreateObject("Excel.Application")

        Dim xlbook As Object = app.workbooks.add()

        Dim xR As Integer = dgv2.Rows.Count

        Dim xC As Integer = dgv2.Columns.Count

        Dim maxR As Integer = 20000

        Dim PageMax As Integer = Int(xR / maxR)

        If CInt(xR / maxR + 0.5) > PageMax Then

            PageMax += 1

        End If

        Dim i As Integer = 0

        Dim col As Integer = 0

        Dim row As Integer = 0

        For j As Integer = 1 To PageMax

            Dim xlsheet As Object = xlbook.worksheets.add()

            xlsheet.name = "工作表" & j

            xlsheet.activate()

            If j = PageMax Then

                maxR = xR - maxR * (PageMax - 1)

            End If

            Dim rawData1(maxR, xC - 1) As Object

            For col = 0 To xC - 1

                rawData1(0, col) = dgv2.Columns(col).ColumnName

            Next

            For row = 0 To maxR - 1

                For col = 0 To xC - 1

                    rawData1(row + 1, col) = dgv2.Rows(i).ItemArray(col).ToString

                Next

                i += 1

            Next

            xlsheet.range(xlsheet.cells(1, 1), xlsheet.cells(maxR + 1, xC)).value2 = rawData1

            xlsheet.Columns.AutoFit()

        Next

        ' ****************

        ' * 砞﹚砰把计 *

        ' ****************

        With app.cells

            '.font.Name = "vendana"

            '.font.Size = 10

            '.HorizontalAlignment = -4108       ' キ﹡い

            '.VerticalAlignment = -4108         ' ﹡い

            .Columns.AutoFit()

        End With

        app.visible = True

        app.Quit()

        DGV1.Columns.Clear()

        Me.StatusBar1.Panels(0).Text = ""

    End Sub

　　DataTable表格导出Excle

如果含有日期格式则需要转换下，oracle 下使用to_char()进行转换成toString格式