Find out username(who) modified file in C#

Question

I am using a FileSystemWatcher to monitor a folder. But when there is some event happening in the directory, I don't know how to search who made a impact on that file. I tried to use EventLog. It just couldn't work. Is there another way to do it?

Answer 1

I cant remember where I found this code but its an alternative to using pInvoke which I think is a bit overkill for this task. Use the FileSystemWatcher to watch the folder and when an event fires you can work out which user made the file change using this code:

private string GetSpecificFileProperties(string file, params int[] indexes)
{
    string fileName = Path.GetFileName(file);
    string folderName = Path.GetDirectoryName(file);
    Shell32.Shell shell = new Shell32.Shell();
    Shell32.Folder objFolder;
    objFolder = shell.NameSpace(folderName);
    StringBuilder sb = new StringBuilder();

    foreach (Shell32.FolderItem2 item in objFolder.Items())
    {
        if (fileName == item.Name)
        {
            for (int i = 0; i < indexes.Length; i++)
            {
                sb.Append(objFolder.GetDetailsOf(item, indexes[i]) + ",");
            }

            break;
        }
    }

    string result = sb.ToString().Trim();
    //Protection for no results causing an exception on the `SubString` method
    if (result.Length == 0)
    {
        return string.Empty;
    }
    return result.Substring(0, result.Length - 1);
}

Shell32 is a reference to the DLL: Microsoft Shell Controls And Automation - its a COM reference

Here is some example's of how you call the method:

string Type = GetSpecificFileProperties(filePath, 2);
string ObjectKind = GetSpecificFileProperties(filePath, 11);
DateTime CreatedDate = Convert.ToDateTime(GetSpecificFileProperties(filePath, 4));
DateTime LastModifiedDate = Convert.ToDateTime(GetSpecificFileProperties(filePath, 3));
DateTime LastAccessDate = Convert.ToDateTime(GetSpecificFileProperties(filePath, 5));
string LastUser = GetSpecificFileProperties(filePath, 10);
string ComputerName = GetSpecificFileProperties(filePath, 53);
string FileSize = GetSpecificFileProperties(filePath, 1);

Or get multiple comma separated properties together:

string SizeTypeAndLastModDate = GetSpecificFileProperties(filePath, new int[] {1, 2, 3});

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Note: This solution has been tested on Windows 7 and Windows 10. It wont work unless running in a STA as per Exception when using Shell32 to get File extended properties and you will see the following error:

Unable to cast COM object of type 'Shell32.ShellClass' to interface type 'Shell32.IShellDispatch6'