With .Net Framework 4.x you can use ReadLines
http://msdn.microsoft.com/en-us/library/dd383503.aspx
For Each line In IO.File.ReadLines(filename)
' do something with the string
Next
ReadLines is an IEnumerable of String, which means that it will read one line after the other. If you use a version where this is not available, you simply replace it with ReadAllLines. ReadAllLines will read all lines at once into an array and then you are iterating over this array. If your file is small there is not much difference between both versions, but if you work with larger files, the first one has a smaller memory footprint and processing starts after reading the first and not when all lines have been read.