look at this site. http://www.dotnetperls.com/readline
using System;
using System.Collections.Generic;
using System.IO;
class Program
{
static void Main()
{
const string f = "TextFile1.txt";
// 1
// Declare new List.
List<string> lines = new List<string>();
// 2
// Use using StreamReader for disposing.
using (StreamReader r = new StreamReader(f))
{
// 3
// Use while != null pattern for loop
string line;
while ((line = r.ReadLine()) != null)
{
// 4
// Insert logic here.
// ...
// "line" is a line in the file. Add it to our List.
lines.Add(line);
}
}
// 5
// Print out all the lines.
foreach (string s in lines)
{
Console.WriteLine(s);
}
}
}
Output
(Prints contents of TextFile1.txt)
This is a text file I created,
Just for this article.
group by ienum
class Pet
{
public string Name { get; set; }
public int Age { get; set; }
}
// Uses method-based query syntax.
public static void GroupByEx1()
{
// Create a list of pets.
List<Pet> pets =
new List<Pet>{ new Pet { Name="Barley", Age=8 },
new Pet { Name="Boots", Age=4 },
new Pet { Name="Whiskers", Age=1 },
new Pet { Name="Daisy", Age=4 } };
// Group the pets using Age as the key value
// and selecting only the pet's Name for each value.
IEnumerable<IGrouping<int, string>> query =
pets.GroupBy(pet => pet.Age, pet => pet.Name);
// Iterate over each IGrouping in the collection.
foreach (IGrouping<int, string> petGroup in query)
{
// Print the key value of the IGrouping.
Console.WriteLine(petGroup.Key);
// Iterate over each value in the
// IGrouping and print the value.
foreach (string name in petGroup)
Console.WriteLine(" {0}", name);
}
}
/*
This code produces the following output:
8
Barley
4
Boots
Daisy
1
Whiskers
*/