用代码覆盖Excel文件

Question

I'm using visual studio 2008 to create a console application on c#.

The application "reads" an excel file 97-2003 (.XLS).

I'm using jet to read the file:

OleDbConnection oConn = new OleDbConnection();
   oConn.ConnectionString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source= " + file_path  + " ;Extended Properties=\"Excel 8.0;HDR=No;IMEX=1\";";    

But when running the program I get error "External table is not in the expected format."

I have tried reading the excel file with the NPOI library and i got error:

Message = "Invalid header signature; read 0x0010000000060809, expected 0xE11AB1A1E011CFD0"

So, it's like the file is invalid in some way.

If, through Windows, I open the excel file on Office Excel, then save it with the same and same extension .xls overwriting it , and after that I run the console application, then the application runs fine with no error.

So, what I would like to do is: with c# code, open the file and save it and overwrite it, so the application could read the file successfully.

I guess I could open the file like this:

File.OpenWrite(file_path);

But how could I overwrite the file?

Answer 1

You don't need to open and rewrite it, as far as I can see. Your connection string is wrong. You're not saying anywhere it's an Excel file, so by default it's looking for an Access database instead (and not finding one).

Try this instead:

Provider=Microsoft.Jet.OLEDB.4.0; data source="YourFileName.xls"; Extended Properties=Excel 8.0;

For other types of connections, see ConnectionStrings