Program that works in all version of excel

Question

I have recently developed a Windows Form application which has several datagrids. My client needs to export the data into Excel. They are using different versions of Excel (i.e 2003,2007,2010,2013) but I'm using Office 2013. I have used excel 2013 references

(Microsoft excel 15.0 object library)

in my program. Recently, my client reported that the export option was not working. From my investigation it seems that my application is working fine for those who are using Office 2013 but not working for previous Office versions.

What can I do to make sure my application works in older versions of Excel?

Answer 1

If you know all your users will have excel, you can convert your excel references to "Object"s instead of hardcoded excel objects and then remove the DLL references from your project. This will work will all versions of office, as long as you don't use some NEW function that is not in the older versions.

For example, instead of this:

Dim _xlApp As Excel.Application
Dim _xlBook As Excel.Workbook

Try this:

Dim _xlApp As Object 'Excel.Application
Dim _xlBook As Object 'Excel.Workbook

Everything works the same (except no intellisence) except for instantiation of the excel application:

_xlApp = CreateObject("Excel.Application") 'New Excel.Application

I have done it this way for 15 years without ever changing my code based on different versions.

Answer 2

There is a way for your application to work even if there is no excel installed at all. You can use native excel libraries, there are free .NET libraries that you can use for that purpose.

For XLS format you can use NPOI and EPPlus for XLSX, downside of this approach is that you will have to change your existing code if you decide to go this way.

EPPlus example of exporting DataTable to excel, from this SO question :

using (ExcelPackage pck = new ExcelPackage(newFile))
{
  ExcelWorksheet ws = pck.Workbook.Worksheets.Add("Accounts");
  ws.Cells["A1"].LoadFromDataTable(dataTable, true);
  pck.Save();
}

For NPOI example look here :

http://dotnetslackers.com/DataSet/re-511450_Export_an_ADO_NET_DataTable_to_Excel_using_NPOI.aspx

Answer 3

Thanks for your help @Steve and @Antonio Bakula

Here is my late binding code which will work on all version of excel ..

 Try
            Dim app As Object
            Dim xlbook As Object
            Dim xlsheet As Object
            app = CreateObject("Excel.Application")
            xlbook = app.Workbooks.Add()
            xlsheet = xlbook.ActiveSheet
            app.Visible = True
            Dim iX As Integer
            Dim iY As Integer
            Dim iC As Integer
            Dim iz As Integer
            For iC = 0 To DataGridView1.Columns.Count - 1
                xlsheet.Cells(1, iC + 1).Value = DataGridView1.Columns(iC).HeaderText
            Next
            iz = 1
            For iX = 0 To DataGridView1.Rows.Count - 1
                For iY = 0 To DataGridView1.Columns.Count - 1
                    Dim a As String = DataGridView1(iY, iX).Value
                    If a <> Nothing Then xlsheet.Cells(iz + 1, iY + 1).value = DataGridView1(iY, iX).Value.ToString
                Next
                iz = iz + 1
            Next

            MsgBox("Export Done", MsgBoxStyle.Information, "MODEL AND WARRANTY")

            app.Visible = True
            app.UserControl = True
            releaseobject(app)
            releaseobject(xlbook)
            releaseobject(xlsheet)
        Catch ex As Exception
            MessageBox.Show(ex.ToString())
        End Try

Release the excel object once extraction is done .

Sub releaseobject(ByVal obj As Object)
    Try
        System.Runtime.InteropServices.Marshal.ReleaseComObject(obj)
        obj = Nothing
    Catch ex As Exception
        obj = Nothing
    End Try
End Sub