C# How to skip number of lines while reading text file using Stream Reader?

Try the following

// Skip 5 lines
for(var i = 0; i < 5; i++) {
  tr.ReadLine();
}

// Read the rest
string remainingText = tr.ReadToEnd();

If the lines are fixed then the most efficient way is as follows:

using( Stream stream = File.Open(fileName, FileMode.Open) )
{
    stream.Seek(bytesPerLine * (myLine - 1), SeekOrigin.Begin);
    using( StreamReader reader = new StreamReader(stream) )
    {
        string line = reader.ReadLine();
    }
}

And if the lines vary in length then you'll have to just read them in a line at a time as follows:

using (var sr = new StreamReader("file"))
{
    for (int i = 1; i <= 5; ++i)
        sr.ReadLine();
}

If you want to use it more times in your program then it maybe a good idea to make a custom class inherited from StreamReader with the ability to skip lines.

Something like this could do:

class SkippableStreamReader : StreamReader
{
    public SkippableStreamReader(string path) : base(path) { }

    public void SkipLines(int linecount)
    {
        for (int i = 0; i < linecount; i++)
        {
            this.ReadLine();
        }
    }
}

after this you could use the SkippableStreamReader's function to skip lines. Example:

SkippableStreamReader exampleReader = new SkippableStreamReader("file_to_read");

//do stuff
//and when needed
exampleReader.SkipLines(number_of_lines_to_skip);