new FileStream(path, FileMode.Open, FileAccess.Read, FileShare.Read, FileOptions.SequentialScan);

or


using (var fileStream = new FileStream("foo.bar", FileMode.Open, FileAccess.Read, FileShare.ReadWrite)


or


    FileStream fileStream = new FileStream("[path]", FileMode.Open, FileAccess.Read, FileShare.Read, 64 * 1024,
        (FileOptions)0x20000000 | FileOptions.WriteThrough & FileOptions.SequentialScan);

or

FileShare.ReadWrite | FileShare.Delete

var fs = new FileStream(FilePathOpen, FileMode.Open, FileAccess.Read, FileShare.ReadWrite|FileShare.Delete);
using (StreamReader reader = new StreamReader(fs)) {
// Read the entire file into a string
string fileContent = reader.ReadToEnd();

// Split the file content into an array of strings
string[] lines = fileContent.Split(new[] { "\r\n", "\r", "\n" }, StringSplitOptions.None);

// Get the last line of the file
string lastLine = lines[lines.Length - 2];

// Split the last line into an array of strings

string[] tokens = lastLine.Split(new char[] { ' ', '\t' }, StringSplitOptions.RemoveEmptyEntries);
float value;

if(tokens.Length == 22)
		if (float.TryParse(tokens[15], NumberStyles.Float, NumberFormatInfo.InvariantInfo, out value)) {
		Values[1]= value*(float)1e6;
		}

// Close the file
reader.Close();
}