file handling in C# .net

There is a list of things I want to do. I have a forms application.

1. Go to a particular line. I know how to go in a serial manner, but is there any way 开发者_JAVA技巧by which I can jump to a particular line no.

2. To find out total no of line.

If the file is not too big, you can try the ReadAllLines.

This reads the whole file, into a string array, where every line is an element of the array.

Example:

var fileName = @"C:\MyFolder\MyFileName.txt";
var contents = System.IO.File.ReadAllLines(fileName);

Console.WriteLine("Line: 10: " + contents[9]);
Console.WriteLine("Number of lines:");
Console.WriteLine(contents.Lenght);

But be aware: This reads in the whole file into memory.

If the file is too big:

Open the file (OpenText), and create a Dictionary to store the offset of every line. Scan every line, and store the offset. Now you can go to every line, and you have the number of lines.

var lineOffset = new Dictionary<int, long>();
using (var rdr = System.IO.File.OpenText(fileName)) {
   int lineNr = 0;
   lineOffset.Add(0,0);
   while (rdr.ReadLine() != null)) {
       lineNr++;
       lineOffset.Add(lineNr, rdr.BaseStream.Position);
   }

   // Goto line 10
   rdr.BaseStream.Position = lineOffset[10];
   var line10 = rdr.ReadLine();
}

This would help for your first point: jump into file line c#