Skystone Software
http://www.SkystoneSoftware.com|
Checking to see if a File is Locked
Published: 10/25/2008 |
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Many applications (like Word, for example) have a proprietary method for locking their files. This usually involves a temporary file written to the same folder as the file being edited by the application, which typically contains some information like what user is editing the file, how long it's been open, etc. Windows also supports a simple file locking mechanism, which simply generates an error when an application attempts to modify or read from a file that is in use by another application. Here's a simple routine that will check to see if a file is already in use by attempting to open it for read access and trapping the appropriate errors:
VB:
Public Function IsFileLocked(ByVal Path As String) As Boolean
Try
Using clsReader As New System.IO.StreamReader("C:\MyFile.txt")
clsReader.Close()
End Using
Return False
Catch exNotFoundDir As System.IO.DirectoryNotFoundException
Throw exNotFoundDir
Catch exNotFound As System.IO.FileNotFoundException
Throw exNotFound
Catch exPathNull As System.ArgumentNullException
Throw exPathNull
Catch exPath As System.ArgumentException
Throw exPath
Catch exLocked As System.IO.IOException
Return True
End Try
End Function
public bool IsFileLocked(string Path)
{
try
{
using (System.IO.StreamReader clsReader = new System.IO.StreamReader("C:\\MyFile.txt"))
{
clsReader.Close();
}
return false;
}
catch (System.IO.DirectoryNotFoundException exNotFoundDir)
{
throw exNotFoundDir;
}
catch (System.IO.FileNotFoundException exNotFound)
{
throw exNotFound;
}
catch (System.ArgumentNullException exPathNull)
{
throw exPathNull;
}
catch (System.ArgumentException exPath)
{
throw exPath;
}
catch (System.IO.IOException exLocked)
{
return true;
}
}
Questions or Comments? .
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