streamwriter c# code example

Example 1: c# streamwriter

// The StreamReader are using the Namespaces: System and system.IO

using (StreamWriter sw = new StreamWriter("c:\WriteLines.txt")) //path
{
  sw.WriteLine("Here goes the text");

}

Example 2: c# write file

class WriteTextFile
{
    static void Main()
    {

        // These examples assume a "C:\Users\Public\TestFolder" folder on your machine.
        // You can modify the path if necessary.

        // Example #1: Write an array of strings to a file.
        // Create a string array that consists of three lines.
        string[] lines = { "First line", "Second line", "Third line" };
        // WriteAllLines creates a file, writes a collection of strings to the file,
        // and then closes the file.  You do NOT need to call Flush() or Close().
        System.IO.File.WriteAllLines(@"C:\Users\Public\TestFolder\WriteLines.txt", lines);

        // Example #2: Write one string to a text file.
        string text = "A class is the most powerful data type in C#. Like a structure, " +
                       "a class defines the data and behavior of the data type. ";
        // WriteAllText creates a file, writes the specified string to the file,
        // and then closes the file.    You do NOT need to call Flush() or Close().
        System.IO.File.WriteAllText(@"C:\Users\Public\TestFolder\WriteText.txt", text);

        // Example #3: Write only some strings in an array to a file.
        // The using statement automatically flushes AND CLOSES the stream and calls
        // IDisposable.Dispose on the stream object.
        // NOTE: do not use FileStream for text files because it writes bytes, but StreamWriter
        // encodes the output as text.
        using (System.IO.StreamWriter file =
            new System.IO.StreamWriter(@"C:\Users\Public\TestFolder\WriteLines2.txt"))
        {
            foreach (string line in lines)
            {
                // If the line doesn't contain the word 'Second', write the line to the file.
                if (!line.Contains("Second"))
                {
                    file.WriteLine(line);
                }
            }
        }

        // Example #4: Append new text to an existing file.
        // The using statement automatically flushes AND CLOSES the stream and calls
        // IDisposable.Dispose on the stream object.
        using (System.IO.StreamWriter file =
            new System.IO.StreamWriter(@"C:\Users\Public\TestFolder\WriteLines2.txt", true))
        {
            file.WriteLine("Fourth line");
        }
    }
}
 //Output (to WriteLines.txt):
 //   First line
 //   Second line
 //   Third line

 //Output (to WriteText.txt):
 //   A class is the most powerful data type in C#. Like a structure, a class defines the data and behavior of the data type.

 //Output to WriteLines2.txt after Example #3:
 //   First line
 //   Third line

 //Output to WriteLines2.txt after Example #4:
 //   First line
 //   Third line
 //   Fourth line

Example 3: stream deflator c#

using System;
using System.IO;
using System.IO.Compression;

public class Program
{
    public static void Compress(DirectoryInfo directorySelected)
    {
      using (FileStream compressedFileStream = File.Create(file.FullName + ".cmp"))
      {
        using (DeflateStream compressionStream = new DeflateStream(compressedFileStream, CompressionMode.Compress))
        {
          originalFileStream.CopyTo(compressionStream);
        }
      }
    }

    public static void Decompress(FileInfo fileToDecompress)
    {
      using (FileStream decompressedFileStream = File.Create(newFileName))
      {
        using (DeflateStream decompressionStream = new DeflateStream(originalFileStream, CompressionMode.Decompress))
        {
          decompressionStream.CopyTo(decompressedFileStream);
          Console.WriteLine("Decompressed: {0}", fileToDecompress.Name);
        }
      }
    }
}

Example 4: creating a streamwiter file C#

StreamWiter writer = new StreamWriter ("Rainfall.txt", true);
writer.WriteLine("")