Dynamic file reading C#

While trying, do I keep my code for reading the txt file i.e should i keep my code same for a static file?

What I came up with was to use a filesystemwatcher object on the file... in case of a change event I would copy the change in data in the original file and write it onto a temp file and then do my calculations on it.
Does this seem like a good idea?
PS: i havent tried this with the interrogator but copy-pasted the data in txt file myself(am I doiing something wrong here?)

//Here is the code for the Change event for a FileSystemWatcher
void watcher_Changed(object sender, FileSystemEventArgs e)
{


try
{

watcher.EnableRaisingEvents = false;
// string tempPath = @"C:\Users\Schumi\Desktop\test_change.txt";
// string ChangePath = @"C:\Users\Schumi\Desktop\change.txt";



// Read the temp file and store the result in memory
string temp = File.ReadAllText(tempPath);
string difference = string.Empty;

// Read newly changed file from Memory
string path = e.FullPath;
StreamReader reader = new StreamReader(path);
string content = reader.ReadToEnd();
reader.Close();

// Compare the File in Memory with the temp file and get the difference
if (content.Length > temp.Length)
{
if (temp.Length > 0)
{

difference = content.Replace(temp, "0.001000 0 3 0 3 1544.827243 1553.255697 1566.026953 1545.584506 1554.146420 1566.362399");
}
else
{
difference = content;
}

File.WriteAllText(tempPath, content);
// temp = content.Replace(temp, "");
File.WriteAllText(ChangePath, difference);
}
else
{

File.WriteAllText(tempPath, content);
}
reader_worker.RunWorkerAsync();

}
finally
{
watcher.EnableRaisingEvents = true;
}



//throw new NotImplementedException();
}