Question

我正在使用Visual Studio 2015.我在一个文件夹中有750个csv文件。我需要删除它们中的某些列（有星号的地方）。当用户在对话框中选择该选项时，我创建了一个项目wpf应用程序。下面是按钮单击时激活的代码。

Class MainWindow
Dim xl As Microsoft.Office.Interop.Excel._Application
Dim wb As Microsoft.Office.Interop.Excel._Workbook
Dim ws As Microsoft.Office.Interop.Excel._Worksheet
Dim iCol As Integer
Dim strName As String
Dim iIndex As Integer
Dim strPath As String
Dim strFile As String

Private Sub button_Click(sender As Object, e As RoutedEventArgs) Handles button.Click
    If cleanRadioButton.IsChecked = True Then
        strPath = "c:\test\old\"
        strFile = Dir(strPath & "*.csv")
        Do While strFile <> ""

            wb = wb.Open(Filename:=strPath & strFile)

            'Loop through the sheets.
            For iIndex = 1 To xl.ActiveWorkbook.Worksheets.Count
                ws = xl.ActiveWorkbook.Worksheets(iIndex)

                'Loop through the columns.
                For iCol = 1 To ws.UsedRange.Columns.Count
                    'Check row 1 of this column for the char of *
                    If InStr(ws.Cells(10, iCol).Value, "*") > 0 Then
                        'We have found a column with the char of *
                        xl.DisplayAlerts = False
                        ws.Columns(iCol).EntireColumn.Delete
                        ws.Columns(iCol + 1).EntireColumn.Delete
                        ws.Columns(iCol + 2).EntireColumn.Delete
                    End If
                Next iCol

            Next iIndex
            wb.SaveAs(Filename:="C:\test\new\" & wb.Name, FileFormat:=51)
            wb.Close(SaveChanges:=False)
            strFile = Dir()

        Loop

        MessageBox.Show("The csv files have now been cleaned.  Congrats.")
    Else inputRadioButton.IsChecked = True
        MessageBox.Show("The data has now been split into Trajectory and ForcePlate input files.  High 5.")
    End If
End Sub End Class

我在编译时没有错误但是在运行时我得到NullReferenceException在第wb = wb.Open(Filename:=strPath & strFile)行未处理。这是因为wb是null并且我相信还没有实例化。我无法解决如何做到这一点，因为你不能在界面上使用New关键字......

有人可以解释一下吗？ THX

Answer 1

感谢您的回复。 Rory是正确的 - WorkbookS是调用Open的对象而不是Workbook。

Matteo NNZ在某种程度上也是正确的。下面是实际适合我的代码（密钥在Imports语句中，并在Microsoft.Office.Interop.Excel的引用属性中设置Embed Interop Types = FALSE）

Imports Excel = Microsoft.Office.Interop.Excel

Class MainWindow Dim xl As Excel.Application = New Excel.ApplicationClass（） Dim wb作为Excel.Workbook Dim ws As Excel.Worksheet 昏暗的iCol作为整数 Dim strName As String Dim iIndex As Integer Dim strPath As String Dim strFile As String

Private Sub button_Click(sender As Object, e As RoutedEventArgs) Handles button.Click
    If cleanRadioButton.IsChecked = True Then
        strPath = "c:\test\old\"
        strFile = Dir(strPath & "*.csv")
        Do While strFile <> ""
            wb = xl.Workbooks.Open(Filename:=strPath & strFile)

            'Loop through the sheets.
            For iIndex = 1 To xl.ActiveWorkbook.Worksheets.Count
                ws = xl.ActiveWorkbook.Worksheets(iIndex)

                'Loop through the columns.
                For iCol = 1 To ws.UsedRange.Columns.Count
                    'Check row 10 of this column for the char of *
                    If InStr(ws.Cells(10, iCol).Value, "*") > 0 Then
                        'We have found a column with the char of *
                        xl.DisplayAlerts = False
                        ws.Columns(iCol).EntireColumn.Delete
                        ws.Columns(iCol).EntireColumn.Delete
                        ws.Columns(iCol).EntireColumn.Delete
                        iCol = iCol - 3
                    End If
                Next iCol

            Next iIndex
            wb.SaveAs(Filename:="C:\test\new\" & wb.Name, FileFormat:=51)
            wb.Close(SaveChanges:=False)
            strFile = Dir()

        Loop

        MessageBox.Show("The csv files have now been cleaned.  Congrats.")
    Else inputRadioButton.IsChecked = True
        MessageBox.Show("The data has now been split into Trajectory and ForcePlate input files.  High 5.")
    End If
End Sub

结束班

希望能帮助下一个人解：导入Excel = Microsoft.Office.Interop.Excel Dim xl As Excel.Application = New Excel.ApplicationClass（）

在Visual Basic中实例化Workbook / excel对象

1 个答案: