computer programming in C#

Question

Need Help please! how to read specific text or range of text or section of text or line of text from a text file.

Željko Perić · Answer

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 { 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 { 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 Shah · Answer

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.

computer programming in C#

Answers (2)