WebApp匯入資料之From Excel

1、情景
點擊“瀏覽”按鈕，尋找要上傳的Excel。按下上傳按鈕，資料寫入資料庫（database）並且顯示在畫面上。
然後，按下“保存”按鈕，Datagrid上的資料寫入DB。
2、分析
按下上傳按鈕，先將Excel上傳到Server上；再將Excel的內容讀入Datatable中；然後刪除Excel檔；最後檢查Datatable的內容正確性，寫入database。
3、實現
上傳按鈕部分
    Protected Sub btnUpload_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnUpload.Click

        ' check is has file
        If Not upExcel.HasFile Then
            JavascriptUtility.Alert(Me, "請先上傳檔案")
            Exit Sub
        End If

        Dim filename As String = String.Empty
        Dim savePath As String = String.Empty
        Dim dt As DataTable = Nothing

        Try
            filename = Format(Now, "yyyyMMddHHmmss") & ".xls"

            ' 上傳檔案
            savePath = ModuleExcel.SaveUploadFile(upExcel, filename)

            ' 讀取Excel的內容
            dt = ModuleExcel.ReadExcel(savePath, 1, "I1ElM", 2, New Integer() {1}, 1)

            ' Delete Excel
            System.IO.File.Delete(savePath)

            ' 計算Excel
            'RunExcel(DataTable)
        Catch ex As System.IO.DirectoryNotFoundException
            JavascriptUtility.Alert(Me, ex.Message)
        Catch ex As ModuleExcel.ExcelColumnDifferenceException
            JavascriptUtility.Alert(Me, ex.Message)
        Catch ex As Exception
            JavascriptUtility.Alert(Me, ex.Message)
        End Try
    End Sub
Excel 操作方法部分
Public Class ModuleExcel
    ''' <summary>
    ''' 上傳Excel文件
    ''' </summary>
    ''' <param name="InputFile">上傳控件</param>
    ''' <param name="Filename">文件名稱(主文件名+擴展名)</param>
    Public Shared Function SaveUploadFile(ByRef InputFile As WebControls.FileUpload, ByVal Filename As String) As String
        Dim path As String = System.Configuration.ConfigurationManager.AppSettings("UploadPath")
        path = System.Web.HttpContext.Current.Server.MapPath(path) & "\" & Filename
        InputFile.SaveAs(path)
        Return path
    End Function

    ''' <summary>
    ''' 讀取Excel的內容
    ''' </summary>
    ''' <param name="excelPath">Excel文件物理路徑</param>
    ''' <param name="sheetIndex">Excel文件索引(從1開始)</param>
    ''' <param name="columnName">Excel欄位名稱(大寫)，逗號分隔。</param>
    ''' <param name="startRowIndex">Excel數據行索引(從1開始)</param>
    ''' <param name="canNotNullColumn">Excel不可空白欄位索引</param>
    ''' <param name="columnCount">Excel欄位總數</param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Shared Function ReadExcel(ByVal excelPath As String, ByVal sheetIndex As Integer, ByVal columnName As String, ByVal startRowIndex As Integer, _
        ByVal canNotNullColumn As Integer(), ByVal columnCount As Integer) As DataTable

        Dim excelApp As New Excel.Application
        Dim workSheet As Excel.Worksheet
        Dim workBook As Excel.Workbook

        Dim Range1 As Excel.Range

        Dim x As Integer

        Dim dataTable As New Data.DataTable

        '開啟Excel檔
        workBook = excelApp.Workbooks.Open(excelPath)

        Try
            ' 取Sheet
            workSheet = workBook.Worksheets.Item(sheetIndex) 'workBook.Worksheets.Item(1)

            ' GetExcelcolumnName:取Excel欄位並且用逗號分隔
            If columnName = GetExcelcolumnName(workSheet, dataTable).ToUpper() Then
                For x = startRowIndex To workSheet.Rows.Count ' For x = 2 To workSheet.Rows.Count ' 數據行

                    Dim notNullCount As Integer = 0
                    For i As Integer = 0 To canNotNullColumn.Length - 1
                        Range1 = workSheet.Cells(x, canNotNullColumn(i))  ' Range1 = workSheet.Cells(x, 1)
                        If CType(Range1.Value, String) <> "" Then
                            notNullCount += 1
                        End If
                    Next

                    If notNullCount = canNotNullColumn.Length Then ' 不可空欄位都不是空
                        For j As Integer = 1 To columnCount 'Excel計數從1開始  ‘ 數據列
                            Range1 = workSheet.Cells(x, j)
                            AddDataRow(dataTable, j - 1, Range1.Value)
                        Next
                    Else  ' 空則認為讀完
                        Exit For
                    End If
                Next
            Else
                Throw New ExcelColumnDifferenceException("指定欄位與Excel實際欄位不一致")
            End If
        Catch ex As ExcelColumnDifferenceException
            Throw ex
        Catch ex As Exception
            Throw New Exception("Read excel wrong", ex)
        Finally
            excelApp.Workbooks.Close()
            excelApp.Quit()
            excelApp = Nothing
        End Try
        Return dataTable
    End Function

    ''' <summary>
    ''' 獲取Excel的欄位
    ''' </summary>
    ''' <param name="workSheet">Excel sheet</param>
    ''' <param name="dataTable">存放資料的table</param>
    ''' <returns></returns>
    ''' <remarks></remarks>
    Public Shared Function GetExcelcolumnName(ByVal workSheet As Excel.Worksheet, ByRef dataTable As Data.DataTable) As String

        If workSheet Is Nothing Then
            Throw New ArgumentNullException("workSheet", "workSheet為空")
        End If

        If workSheet Is Nothing Then
            Throw New ArgumentNullException("dataTable", "dataTable為空")
        End If

        Dim sCol As String = String.Empty
        For i As Integer = 1 To workSheet.Columns.Count
            Dim Range1 As Excel.Range
            Dim cellV As String = String.Empty
            Range1 = workSheet.Cells(1, i)
            cellV = CType(Range1.Value, String)

            If cellV <> String.Empty Then
                ' Join column
                sCol &= cellV & ","
                ' Create column
                dataTable.Clear()
                dataTable.Columns.Add(cellV)
            Else
                Exit For
            End If
        Next

        If sCol.Length > 0 Then
            Dim _idx As Integer = sCol.LastIndexOf(",")
            If _idx > -1 Then
                sCol = sCol.Substring(0, _idx)
            End If
        End If
        Return sCol
    End Function

    ''' <summary>
    ''' 新增資料行
    ''' </summary>
    ''' <param name="dataTable">資料表</param>
    ''' <param name="columnIndex">列索引</param>
    ''' <param name="rowValue">值</param>
    ''' <remarks></remarks>
    Public Shared Sub AddDataRow(ByRef dataTable As Data.DataTable, ByVal columnIndex As Integer, ByVal rowValue As String)
        If dataTable Is Nothing Then
            Throw New ArgumentNullException("dataTable", "dataTable為空")
        End If

        If columnIndex < 0 Then
            Throw New ArgumentOutOfRangeException("columnIndex", "columnIndex超出Excel欄範圍")
        End If

        Dim dr As Data.DataRow
        dr = dataTable.NewRow
        dr(columnIndex) = rowValue
        dataTable.Rows.Add(dr)

    End Sub

    Public Class ExcelColumnDifferenceException
        Inherits System.ArgumentException
        Public Sub New(ByVal message As [String])
            MyBase.New(message)
        End Sub
        Public Sub New(ByVal message As [String], ByVal innerException As Exception)
            MyBase.New(message, innerException)
        End Sub
    End Class
End Class

注意
使用office Excel元件操作Excel，需要設定DCOM+的權限。
1，“控制臺”-->“系統管理工具”-->“元件服務”，然後找到“DCOM設定”。如下圖