computer programming in C#

Hello, if You know the number of lines inside *.txt file this would be the answer.

Suppose we have a txt file "Customer data.txt" containing data abot exactly 10 customers.Each line inside file contains data about one customer.

Load line by line of text from file by using StreamReader class ( namespace System.IO ), and its methods ReadLine(), Close() and Dispose(). Read all about it at URL :

https://msdn.microsoft.com/en-us/library/system.io.streamreader(v=vs.110).aspx

using System;
using System.IO;
namespace Load_data
{
class Program
{
public static void Main(string[] args)
{
Console.WriteLine("Press any key to load data :");
Console.ReadKey(true);
// File path
string file_path = "Customer data.txt";
// Create new stream reader
StreamReader load = new StreamReader(file_path);
// Line of text from file
string line = string.Empty;
// Number of lines inside txt file
int l = 10;
// Data array
string [] customers = new string[l];
// Read data line by line from file
// and store it to array
for (int i = 0; i < l; i++)
{
line = load.ReadLine();
customers[i] = line;
}
// After reading all data
// close and dispose stream reader
// and release all resources asociated with reader
load.Close();
load.Dispose();
// Show data at console
foreach(var c in customers)
{
Console.WriteLine(c);
}
Console.Write("Press any key to continue . . . ");
Console.ReadKey(true);
}
}
}

After loading data to array, You can select and manipulate txt data from file.

If You do not know the number of lines inside txt file this would be one of possible solutions :

using System;
using System.IO;
namespace Load_data
{
class Program
{
public static void Main(string[] args)
{
Console.WriteLine("Press any key to load data :");
Console.ReadKey(true);
// File path
string file_path = "Customer data.txt";
// Create new stream reader
StreamReader load = new StreamReader(file_path);
// Line of text from file
string line = string.Empty;
// Number of lines inside txt file
int l = 0;
// Read line by line, from begining to the end of txt file
// and count lines
l = 0;
while(!load.EndOfStream)
{
line = load.ReadLine();
l++;
}
// Close stream reader and release
// all resources asociated with reader
load.Close();
// Initialize new reader with same file name
load = new StreamReader(file_path);
// Data array
string [] customers = new string[l];
// Read data line by line from file
// and store it to array
for (int i = 0; i < l; i++)
{
line = load.ReadLine();
customers[i] = line;
}
// After reading all data
// close and dispose stream reader
// and release all resources asociated with reader
load.Close();
// Dispose reader
// After this step variable "load"
// do not exists at program any more and can't be initialized again
load.Dispose();
// Show data at console
foreach(var c in customers)
{
Console.WriteLine(c);
}
Console.Write("Press any key to continue . . . ");
Console.ReadKey(true);
}
}
}

NOTICE :

Instead of closing and initializing new stream reader for the same txt file like in the code above , just to enable reading of the same file from the begining ,

// Close stream reader and release
// all resources asociated with reader
load.Close();
// Initialize new reader with same file name
load = new StreamReader(file_path);

there is another method for reseting stream reader to the begining of stream.

load.BaseStream.Seek(0, SeekOrigin.Begin);

try it :)

https://stackoverflow.com/questions/2053206/return-streamreader-to-beginning

All the best,

Željko Peric

2 Replies

Know the answer? Post it — somebody with the same question will find it here.

Željko Perić8y ago
Hello, if You know the number of lines inside *.txt file this would be the answer.
Suppose we have a txt file "Customer data.txt" containing data abot exactly 10 customers.Each line inside file contains data about one customer.
Load line by line of text from file by using StreamReader class ( namespace System.IO ), and its methods ReadLine(), Close() and Dispose(). Read all about it at URL :

https://msdn.microsoft.com/en-us/library/system.io.streamreader(v=vs.110).aspx
using System;
using System.IO;

namespace Load_data
{
    class Program
    {
        public static void Main(string[] args)
        {
            Console.WriteLine("Press any key to load data :");
            Console.ReadKey(true);

            // File path
            string file_path = "Customer data.txt";

            // Create new stream reader
            StreamReader load = new StreamReader(file_path);

            // Line of text from file
            string line = string.Empty;

            // Number of lines inside txt file
            int l = 10;

            // Data array
            string [] customers = new string[l];

            // Read data line by line from file
            // and store it to array
            for (int i = 0; i < l; i++)
            {
                line = load.ReadLine();

                customers[i] = line;

            }

            // After reading all data
            // close and dispose stream reader
            // and release all resources asociated with reader
            load.Close();
            load.Dispose();

            // Show data at console
            foreach(var c in customers)
            {
                Console.WriteLine(c);
            }


            Console.Write("Press any key to continue . . . ");
            Console.ReadKey(true);
        }
    }
}
After loading data to array, You can select and manipulate txt data from file.

If You do not know the number of lines inside txt file this would be one of possible solutions :
using System;
using System.IO;

namespace Load_data
{
    class Program
    {
        public static void Main(string[] args)
        {
            Console.WriteLine("Press any key to load data :");
            Console.ReadKey(true);

            // File path
            string file_path = "Customer data.txt";

            // Create new stream reader
            StreamReader load = new StreamReader(file_path);

            // Line of text from file
            string line = string.Empty;

            // Number of lines inside txt file
            int l = 0;

            // Read line by line, from begining to the end of txt file
            // and count lines
            l = 0;
            while(!load.EndOfStream)
            {
                line = load.ReadLine();
                l++;
            }

            // Close stream reader and release
            // all resources asociated with reader
            load.Close();

            // Initialize new reader with same file name
            load = new StreamReader(file_path);


            // Data array
            string [] customers = new string[l];

            // Read data line by line from file
            // and store it to array
            for (int i = 0; i < l; i++)
            {
                line = load.ReadLine();

                customers[i] = line;

            }

            // After reading all data
            // close and dispose stream reader
            // and release all resources asociated with reader
            load.Close();

            // Dispose reader
            // After this step variable "load"
            // do not exists at program any more and can't be initialized again
            load.Dispose();

            // Show data at console
            foreach(var c in customers)
            {
                Console.WriteLine(c);
            }


            Console.Write("Press any key to continue . . . ");
            Console.ReadKey(true);
        }
    }
}
NOTICE :
Instead of closing and initializing new stream reader for the same txt file like in the code above , just to enable reading of the same file from the begining ,
// Close stream reader and release
// all resources asociated with reader
load.Close();

// Initialize new reader with same file name
load = new StreamReader(file_path);
there is another method for reseting stream reader to the begining of stream.
load.BaseStream.Seek(0, SeekOrigin.Begin);
try it :)

https://stackoverflow.com/questions/2053206/return-streamreader-to-beginning

All the best,
Željko Peric
Nilesh Shah8y ago
did you google?

https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/file-system/how-to-read-a-text-file-one-line-at-a-time

try something on your own, if your requirement is not fulfilled and if you are stuck somewhere then post whatever code you have written with the text file explaining what you want to read.