Excel导出不带Interop [英] Excel export without Interop

问题描述

我正在尝试从VB.NET（Windows Forms）应用程序导出到Excel。

不幸的是，我不能使用Office Interops，因为应用程序应该在每台机器上工作 - 即使没有安装Excel。

我在网上找到以下示例：

公开Sub ExportDatasetToExcel（ByVal ds As DataSet，可选ByVal strHeader As String =另存为）

'自豪地复制：
' http://www.daniweb.com/software-development/vbnet/threads/368400/write-into-excel-using-oledb-connection#post1583200

Dim fileSave As New SaveFileDialog（）

fileSave.Filter =Excel 97-2003工作簿（* .xls）| * .xls
fileSave.InitialDirectory = Environment.GetFolderPath（Environment.SpecialFolder.Desktop）
fileSave。 Title = strHeader
fileSave.ShowDialog（）

Dim xlsFilePath As String = fileSave.FileName

如果xlsFilePath =然后
Exit Sub
End If

System.IO.File.Copy（storagePath& \& empty.xls，xlsFilePath）

Cursor.Current = Cursors.WaitCursor

Dim conn As New OleDb.OleDbConnection（String.Format（provider = Microsoft.Jet。 OLEDB.4.0; Data Source ='{0}';&扩展属性='Excel 8.0; HDR = YES;'，xlsFilePath））

conn.Open（）

Dim strTableQ（ds.Tables.Count）As String

Dim i As Integer = 0

'make table query
For i = 0 to ds.Tables.Count - 1

strTableQ（i）=CREATE TABLE [& ds.Tables（i）.TableName& ]（

Dim j As Integer = 0
For j = 0 To ds.Tables（i）.Columns.Count - 1
Dim dCol As DataColumn
dCol = ds.Tables（i）.Columns（j）
strTableQ（i）& =[& dCol.ColumnName&] varchar（255），
Next
strTableQ（i）= strTableQ（i）.Substring（0，strTableQ（i）.Length - 2）
strTableQ（i）& =）

Dim cmd As新的OleDb.OleDbCommand（strTableQ（i），conn）
cmd.ExecuteNonQuery（）

下一个

'进行插入查询
Dim strInsertQ .Tables.Count - 1）As String
For i = 0 To ds.Tables.Count - 1
strInsertQ（i）=Insert Into& ds.Tables（i）.TableName& 值（
对于k As Integer = 0到ds.Tables（i）.Columns.Count - 1
strInsertQ（i）& =@& ds.Tables（i）。列（k）.ColumnName&，
Next
strInsertQ（i）= strInsertQ（i）.Substring（0，strInsertQ（i）.Length - 2）
strInsertQ ）
下一个

'现在插入数据
For i = 0 To ds.Tables.Count - 1
对于j As Integer = 0 to ds.Tables（i）.Rows.Count - 1
Dim cmd As New OleDb.OleDbCommand（strInsertQ（i），conn）
对于k As Integer = 0到ds.Tables（i）。 Columns.Count - 1
cmd.Parameters.AddWithValue（@& ds.Tables（i）.Columns（k）.ColumnName.ToString（），ds.Tables（i）.Rows（j）（ k）.ToString（））
下一个
cmd.ExecuteNonQuery（）
cmd.Parameters.Clear（）
下一个
下一个
conn.Close ）
conn.Dispose（）
Cursor.Current = Cursors.Default
End Sub

此代码可以将我的数据集导出到.xls文件。

问题：我的程序运行时无法打开此文件。看来我的程序仍然有一个这个文件的句柄。每当我使用Sysinternals Process Explorer时，我都可以看到它。如果我关闭我的程序，我可以打开这个文件没有任何问题。

我想我必须摧毁一些对象或者只是关闭文件。请问有人可以帮助noob来完成吗？

解决方案

我不知道这是否是问题。你不要处理 OleDbCommand 对象。它可能保留对该文件的引用。尝试这样：

  Public Sub ExportDatasetToExcel（ByVal ds As DataSet，可选ByVal strHeader As String =另存为）
 
'自豪地复制自：
'http://www.daniweb.com/software-development/vbnet/threads/368400/write-into-excel-using-oledb-connection#post1583200 
 
使用fileSave作为新的SaveFileDialog（）
 fileSave.Filter =Excel 97-2003工作簿（* .xls）| * .xls
 fileSave.InitialDirectory = Environment.GetFolderPath（Environment .SpecialFolder.Desktop）
 fileSave.Title = strHeader 
 
如果fileSave.ShowDialog（）= Windows.Forms.DialogResult.OK然后
 Dim xlsFilePath As String = fileSave.FileName 
如果xlsFilePath =然后退出Sub 
 
 System.IO.File.Copy（storagePath&\&empty.xls，xlsFilePath）
 
 Cursor.Current = Cursors.WaitCursor 
 
使用conn作为新的OleDb.OleDbConnection（String.Fo RMAT（提供者= Microsoft.Jet.OLEDB.4.0; Data Source ='{0}';&Extended Properties ='Excel 8.0; HDR = YES;'，xlsFilePath））
 conn.Open（）
 Dim strTableQ（ds.Tables。 Count）As String 
 Dim i As Integer = 0 
 
'make table query 
 For i = 0 To ds.Tables.Count  -  1 
 strTableQ（i） =CREATE TABLE [& ds.Tables（i）.TableName&]（
 
 Dim j As Integer = 0 
 For j = 0 To ds.Tables（i ）.Columns.Count  -  1 
 Dim dCol As DataColumn 
 dCol = ds.Tables（i）.Columns（j）
 strTableQ（i）& =[& dCol。 columnName&] varchar（255），
 Next 
 strTableQ（i）= strTableQ（i）.Substring（0，strTableQ（i）.Length  -  2）
 strTableQ ）& =）
 
使用cmd作为新的OleDb.OleDbCommand （strTableQ（i），conn）
 cmd.ExecuteNonQuery（）
结束使用
下一个
 
'使插入查询
 Dim strInsertQ（ds.Tables .Count  -  1）As String 
 For i = 0 To ds.Tables.Count  -  1 
 strInsertQ（i）=Insert Into& ds.Tables（i）.TableName& 值（
对于k As Integer = 0到ds.Tables（i）.Columns.Count  -  1 
 strInsertQ（i）& =@& ds.Tables（i）。列（k）.ColumnName&，
 Next 
 strInsertQ（i）= strInsertQ（i）.Substring（0，strInsertQ（i）.Length  -  2）
 strInsertQ ）
下一个
 
'现在插入数据
 For i = 0 To ds.Tables.Count  -  1 
对于j As Integer = 0 ds.Tables（i）.Rows.Count  -  1 
使用cmd作为新的OleDb.OleDbCommand（strInsertQ（i），conn）
对于k As Integer = 0到ds.Tables（i）。 Columns.Count  -  1 
 cmd.Parameters.AddWithValue（@& ds.Tables（i）.Columns（k）.ColumnName.ToString（），ds.Tables（i）.Rows（j）（ k）.ToString（））
下一个
 cmd.ExecuteNonQuer y（）
 cmd.Parameters.Clear（）
结束使用
下一个
下一个
 conn.Close（）
 Cursor.Current = Cursors.Default 
 
结束使用
如果
结束使用
 End Sub 
  

另请注意，您显示为 ShowDialog（）方法的表单也必须处理。

I'm trying to accomplish export to Excel from a VB.NET (Windows Forms) application.

Unfortunately, I can't use Office Interops because the application should work on every machine - even if there is no Excel installed.

I found the following sample on the Net:

Public Sub ExportDatasetToExcel(ByVal ds As DataSet, Optional ByVal strHeader As String = "Save As")

    'Proudly copied from:
    'http://www.daniweb.com/software-development/vbnet/threads/368400/write-into-excel-using-oledb-connection#post1583200

    Dim fileSave As New SaveFileDialog()

    fileSave.Filter = "Excel 97-2003 Workbook (*.xls)|*.xls"
    fileSave.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop)
    fileSave.Title = strHeader
    fileSave.ShowDialog()

    Dim xlsFilePath As String = fileSave.FileName

    If xlsFilePath = "" Then
        Exit Sub
    End If

    System.IO.File.Copy(storagePath & "\" & "empty.xls", xlsFilePath)

    Cursor.Current = Cursors.WaitCursor

    Dim conn As New OleDb.OleDbConnection(String.Format("provider=Microsoft.Jet.OLEDB.4.0; Data Source='{0}';" & "Extended Properties='Excel 8.0;HDR=YES;'", xlsFilePath))

    conn.Open()

    Dim strTableQ(ds.Tables.Count) As String

    Dim i As Integer = 0

    'making table query
    For i = 0 To ds.Tables.Count - 1

        strTableQ(i) = "CREATE TABLE [" & ds.Tables(i).TableName & "]("

        Dim j As Integer = 0
        For j = 0 To ds.Tables(i).Columns.Count - 1
            Dim dCol As DataColumn
            dCol = ds.Tables(i).Columns(j)
            strTableQ(i) &= " [" & dCol.ColumnName & "] varchar(255) , "
        Next
        strTableQ(i) = strTableQ(i).Substring(0, strTableQ(i).Length - 2)
        strTableQ(i) &= ")"

        Dim cmd As New OleDb.OleDbCommand(strTableQ(i), conn)
        cmd.ExecuteNonQuery()

    Next

    'making insert query
    Dim strInsertQ(ds.Tables.Count - 1) As String
    For i = 0 To ds.Tables.Count - 1
        strInsertQ(i) = "Insert Into " & ds.Tables(i).TableName & " Values ("
        For k As Integer = 0 To ds.Tables(i).Columns.Count - 1
            strInsertQ(i) &= "@" & ds.Tables(i).Columns(k).ColumnName & " , "
        Next
        strInsertQ(i) = strInsertQ(i).Substring(0, strInsertQ(i).Length - 2)
        strInsertQ(i) &= ")"
    Next

    'Now inserting data
    For i = 0 To ds.Tables.Count - 1
        For j As Integer = 0 To ds.Tables(i).Rows.Count - 1
            Dim cmd As New OleDb.OleDbCommand(strInsertQ(i), conn)
            For k As Integer = 0 To ds.Tables(i).Columns.Count - 1
                cmd.Parameters.AddWithValue("@" & ds.Tables(i).Columns(k).ColumnName.ToString(), ds.Tables(i).Rows(j)(k).ToString())
            Next
            cmd.ExecuteNonQuery()
            cmd.Parameters.Clear()
        Next
    Next
    conn.Close()
    conn.Dispose()
    Cursor.Current = Cursors.Default
End Sub

This code works and exports my dataset to an .xls file.

The problem: I can't open this file while my program is running. It seems my program is still having a handle on this file. I can see it whenever I use the Sysinternals Process Explorer. If I close my program, I can open this file without any problems.

I think I have to destroy some object or just close the file. Please could anyone help a noob to accomplish it?

解决方案

I don't know if this is the problem, it could. You do not Dispose the OleDbCommand objects. It's possible that it maintains a reference to the file. Try this:

Public Sub ExportDatasetToExcel(ByVal ds As DataSet, Optional ByVal strHeader As String = "Save As")

    'Proudly copied from:
    'http://www.daniweb.com/software-development/vbnet/threads/368400/write-into-excel-using-oledb-connection#post1583200

    Using fileSave As New SaveFileDialog()
        fileSave.Filter = "Excel 97-2003 Workbook (*.xls)|*.xls"
        fileSave.InitialDirectory = Environment.GetFolderPath(Environment.SpecialFolder.Desktop)
        fileSave.Title = strHeader

        If fileSave.ShowDialog() = Windows.Forms.DialogResult.OK Then
            Dim xlsFilePath As String = fileSave.FileName
            If xlsFilePath = "" Then Exit Sub

            System.IO.File.Copy(storagePath & "\" & "empty.xls", xlsFilePath)

            Cursor.Current = Cursors.WaitCursor

            Using conn As New OleDb.OleDbConnection(String.Format("provider=Microsoft.Jet.OLEDB.4.0; Data Source='{0}';" & "Extended Properties='Excel 8.0;HDR=YES;'", xlsFilePath))
                conn.Open()
                Dim strTableQ(ds.Tables.Count) As String
                Dim i As Integer = 0

                'making table query
                For i = 0 To ds.Tables.Count - 1
                    strTableQ(i) = "CREATE TABLE [" & ds.Tables(i).TableName & "]("

                    Dim j As Integer = 0
                    For j = 0 To ds.Tables(i).Columns.Count - 1
                        Dim dCol As DataColumn
                        dCol = ds.Tables(i).Columns(j)
                        strTableQ(i) &= " [" & dCol.ColumnName & "] varchar(255) , "
                    Next
                    strTableQ(i) = strTableQ(i).Substring(0, strTableQ(i).Length - 2)
                    strTableQ(i) &= ")"

                    Using cmd As New OleDb.OleDbCommand(strTableQ(i), conn)
                        cmd.ExecuteNonQuery()
                    End Using
                Next

                'making insert query
                Dim strInsertQ(ds.Tables.Count - 1) As String
                For i = 0 To ds.Tables.Count - 1
                    strInsertQ(i) = "Insert Into " & ds.Tables(i).TableName & " Values ("
                    For k As Integer = 0 To ds.Tables(i).Columns.Count - 1
                        strInsertQ(i) &= "@" & ds.Tables(i).Columns(k).ColumnName & " , "
                    Next
                    strInsertQ(i) = strInsertQ(i).Substring(0, strInsertQ(i).Length - 2)
                    strInsertQ(i) &= ")"
                Next

                'Now inserting data
                For i = 0 To ds.Tables.Count - 1
                    For j As Integer = 0 To ds.Tables(i).Rows.Count - 1
                        Using cmd As New OleDb.OleDbCommand(strInsertQ(i), conn)
                            For k As Integer = 0 To ds.Tables(i).Columns.Count - 1
                                cmd.Parameters.AddWithValue("@" & ds.Tables(i).Columns(k).ColumnName.ToString(), ds.Tables(i).Rows(j)(k).ToString())
                            Next
                            cmd.ExecuteNonQuery()
                            cmd.Parameters.Clear()
                        End Using
                    Next
                Next
                conn.Close()
                Cursor.Current = Cursors.Default

            End Using
        End If
    End Using
End Sub

Also note that a form that you display with ShowDialog() method must be disposed too.

这篇关于Excel导出不带Interop的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！