how to check if a file is open in vb.net?

_{Thursday, January 24, 2013 11:22 AM}

Hi All

I use a command for open a file for example:

Process.Start(EZCADFile_Copy_Path)

now I want to check if file is open :

1- close file

2- open file again

how to check if a file is open?

if file is open then

close file (EZCADFile_Copy_Path)

Process.Start(EZCADFile_Copy_Path)

end if

thanks a lot****

Best Regard Fatemeh AmirAfshar

_{Thursday, January 24, 2013 1:13 PM ✅Answered | 2 votes}

Fatemah Amir

Hope this helps as below code checks if file is open in vb.net. modify accordingly

    Try
            Dim fOpen As IO.FileStream = IO.File.Open("your file name", IO.FileMode.Open, IO.FileAccess.Read, IO.FileShare.None)
            fOpen.Close()
            fOpen.Dispose()
            fOpen = Nothing
        Catch e1 As IO.IOException
            'File Open by some one else..
        Catch e2 As Exception
        End Try

_{Friday, January 25, 2013 6:54 AM ✅Answered | 1 vote}

Another way to check whether a file is in use is to call the CreateFile API. If a file is in use, the handle return is invalid.

[DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
    private static extern SafeFileHandle CreateFile(string lpFileName,
    FileSystemRights dwDesiredAccess, FileShare dwShareMode, IntPtr
    securityAttrs, FileMode dwCreationDisposition, FileOptions
    dwFlagsAndAttributes, IntPtr hTemplateFile);

        const int ERROR_SHARING_VIOLATION = 32;

        private bool IsFileInUse(string fileName)
        {
            bool inUse = false;

            SafeFileHandle fileHandle = 
            CreateFile(fileName, FileSystemRights.Modify, 
                  FileShare.Write, IntPtr.Zero,                  
                  FileMode.OpenOrCreate, FileOptions.None, IntPtr.Zero);

            if (fileHandle.IsInvalid)
            {
               if (Marshal.GetLastWin32Error() == 
                   ERROR_SHARING_VIOLATION)
               {
                   inUse = true;
               }           
            }
            fileHandle.Close();
            return inUse;
        }

Reference link:  FAQ: How do I check whether a file is in use? 

Best regards,

Shanks Zen
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_{Wednesday, November 14, 2018 7:57 PM}

Sure wish they would lock old threads that have an answer.

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