使用C＃和Excel 2010打开时如何在不获取格式警告的情况下保存Excel文件

Question

I'm using Excel 2010. I'm trying so save my excel file, with this code. It does save a .xls file, but when I open the file I get this message:

The file you are trying to open, 'tre.xls', is in a different format than specified by the file extension. Verify that the file is not corrupted and is from a thrusted source before opening the file. Do you want to open the file now?

If I press yes the file opens. But what do I need to get rid of this format-popup?

My code:

using System;
using System.Windows.Forms;
using ExcelAddIn1.Classes;
using ExcelAddIn1.Classes.Config;
using Microsoft.Office.Interop.Excel;
using Application = Microsoft.Office.Interop.Excel.Application;
using System.Runtime.InteropServices;


private void Foo(object sender, EventArgs e)
{
    SaveFileDialog saveFileDialog = new SaveFileDialog();
    saveFileDialog.Filter = "Execl files (*.xls)|*.xls";
    saveFileDialog.FilterIndex = 0;
    saveFileDialog.RestoreDirectory = true;
    saveFileDialog.CreatePrompt = true;
    saveFileDialog.FileName = null;
    saveFileDialog.Title = "Save path of the file to be exported";

    if (saveFileDialog.ShowDialog() == DialogResult.OK)
    {
        // Save. 
        // The selected path can be got with saveFileDialog.FileName.ToString()
        Application excelObj = 
            (Application)Marshal.GetActiveObject("Excel.Application");
        Workbook wbook = excelObj.ActiveWorkbook;
        wbook.SaveAs(saveFileDialog.FileName, XlFileFormat.xlWorkbookDefault, 
            Type.Missing, Type.Missing, false, false, 
            XlSaveAsAccessMode.xlNoChange, Type.Missing, Type.Missing, 
            Type.Missing, Type.Missing, Type.Missing);
        wbook.Close();
    }
}

When I save in excel in the normal way I get "Book1.xlsx", that have no problem to open.

============= FINAL SOLUTION ============

private void Foo(object sender, EventArgs e)
{
    SaveFileDialog saveFileDialog = new SaveFileDialog();
    saveFileDialog.Filter = "Execl files (*.xls)|*.xls";

    saveFileDialog.FilterIndex = 0;
    saveFileDialog.RestoreDirectory = true;
    saveFileDialog.CreatePrompt = true;
    saveFileDialog.FileName = null;
    saveFileDialog.Title = "Save path of the file to be exported";

    if (saveFileDialog.ShowDialog() == DialogResult.OK)
    {
        Application excelObj = (Application)Marshal.GetActiveObject("Excel.Application");
        Activate(); // <-- added (recommend by msdn, but maybe not nessary here)
        Workbook wbook = excelObj.ActiveWorkbook;
        wbook.SaveAs(saveFileDialog.FileName, XlFileFormat.xlExcel8, Type.Missing,
            Type.Missing, false, false, XlSaveAsAccessMode.xlNoChange, Type.Missing,
            Type.Missing, Type.Missing, Type.Missing, Type.Missing);
        //                wbook.Close(); // <-- don't want this anymore
    }
}

Answer 1

With your code you save the workbook as Open XML because XlFileFormat.xlWorkbookDefault evaluates to XlFileFormat.xlOpenXMLWorkbook for Excel 2007+. This is the reason of the warning: you named the file as XLS but actually it is a XLSX.

You can change the file extension to xlsx in your saveFileDialog.Filter property or force the Excel object to save in the XLS format using XlFileFormat.xlExcel8 .

EDIT
Use this to save your document:

wbook.SaveAs(saveFileDialog.FileName, XlFileFormat.xlExcel8, 
            Type.Missing, Type.Missing, false, false, 
            XlSaveAsAccessMode.xlNoChange, Type.Missing, Type.Missing, 
            Type.Missing, Type.Missing, Type.Missing);

Answer 2

尝试将警报设置为OFF

oExcel.DisplayAlerts = false;   

Answer 3

This problem results from a feature called Extension Hardening, and you can find more information about it here .

Unfortunately, the link above also states that there are no expected changes to this code until at least Office 14.

If you don't want to look for a solution, but just want to solve the problem, insert this key in your registry to suppress the notification:

[HKEY_CURRENT_USER\Software\Microsoft\Office\12.0\Excel\Security] “ExtensionHardening”=dword:00000000

You can accomplish the above by doing the following:

Open your Registry ( Start -> Run -> regedit.exe ).

Navigate to HKEY_CURRENT_USER\\SOFTWARE\\MICROSOFT\\OFFICE\\12.0\\EXCEL\\SECURITY .

Right click in the right window and choose New -> DWORD

Type “ ExtensionHardening ” as the name (without the quotes)

Verify that the data has the value “ 0 ″.