Read Lines from file into Memory,Directly From HDD

hdd.cs

var fileRead = System.IO.File.OpenText("test.txt");
while (fileRead.Peek() != -1)
{
	string line = fileRead.ReadLine();
	// here your code
}
fileRead.Close();

hdd_as_function.cs

public static IEnumerable<string> ReadLinesFile(string filename)
{
	var fileRead = System.IO.File.OpenText(filename);
	while (fileRead.Peek() != -1)
	{
		string line = fileRead.ReadLine();
		yield return line;
	}
	fileRead.Close();
}

/* usage */

foreach (var line in ReadLinesFile("test.txt"))
{
	// here your code
}

/******/

hdd_as_function_from_ms.cs

foreach (var item in System.IO.File.ReadLines("test.txt"))
{

}

mem.cs

string[] lines = System.IO.File.ReadAllLines("test.txt", Encoding.UTF8);