Open and read a file into streams:
using System.IO;
StreamReader sr = new StreamReader("test.txt");
string strLine = sr.ReadLine();
while (!sr.EndOfStream)
{
...
strLine = sr.ReadLine();
}
sr.Close();
using System.IO.File;
string str = File.ReadAllText("Text.txt");
using System.IO.File;
string[] arrlines = File.ReadAllLines("Text.txt");
foreach (string thisline in arrlines)
{
...
}