Question

How can I check if the excel file on which I am working (manipulating its data, deleting it or overwriting it) is in use by another program? And how to release it from the same?

Please guide me using C#.

Answer 1

Attempt to open in with flags “for writing”. If it fails, the file is “taken” by some other process.

FileStream fileStream = null;

try
{
    fileStream =
        new FileStream(@"c:\file.txt", FileMode.Open, FileAccess.Write);
}
catch (UnauthorizedAccessException e)
{
    // The access requested is not permitted by the operating system
    // for the specified path, such as when access is Write or ReadWrite
    // and the file or directory is set for read-only access. 
}
finally
{
    if (fileStream != null)
        fileStream.Close ();
}

P.S. Just found a very similar question with basically the same answer:

C#: Is there a way to check if a file is in use?