What is FileStream Class in C# and How to applied read/write Operation with its

What is FileStream and File Class in C# and How to applied read/write Operation with its......

FileStream can be used to perform the basic operations of reading and writing operating system files. To use this class, you must first declare a variable of the class FileStream.

Parameters:

• Path:  A relative or absolute path for the file that the current FileStream object will encapsulate.
• Mode: A constant that determines how to open or create the file.
• Access: A constant that determines how the file can be accessed by the FileStreamobject. This gets the System.IO.FileStream.CanRead ,System.IO.FileStream.CanWrite properties of the FileStream object. System.IO.FileStream.CanSeek is true if path specifies a disk file.

Exceptions:

1. System.ArgumentNullException:nd 
2. System.ArgumentException:
3. System.NotSupportedException:
4. System.IO.FileNotFoundException:
5. System.IO.IOException:
6. System.Security.SecurityException:
7. System.IO.PathTooLongException:
8. System.ArgumentOutOfRangeException:
9. System.UnauthorizedAccessException:
10. System.IO.DirectoryNotFoundException:
11. System.UnauthorizedAccessException:

Source Code:…………….

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

// using this  namespace

using System.IO;

namespace BasicwithFileHanding

{

public partial class FileStreamConcept : Form

{

public FileStreamConcept()

{

InitializeComponent();

}

string filepath, strcontent;

// code for how to create TextBox with Browse Concept with using openFileDialog1……………………

private void btnBrowse_Click(object sender, EventArgs e)

{

if (openFileDialog1.ShowDialog() == DialogResult.OK)

{

txtselectedFile.Text = openFileDialog1.FileName;

filepath = txtselectedFile.Text;

}

}

//  create method for WriteFile………………………..

public void WriteFile(string FileName, string content)

{

FileStream fs = new FileStream(FileName, FileMode.Create, FileAccess.Write);

if (fs.CanWrite)

{

byte[] buffer = Encoding.ASCII.GetBytes(content);

fs.Write(buffer, 0, buffer.Length);

}

fs.Flush();

fs.Close();

}

string result;

//  create method for ReadFile…………………

public void ReadFile(string FileName)

{

FileStream fs = new FileStream(FileName, FileMode.Open, FileAccess.Read);

if (fs.CanRead)

{

byte[] buffer = new byte[fs.Length];

int bytesread = fs.Read(buffer, 0, buffer.Length);

result = Encoding.ASCII.GetString(buffer, 0, bytesread);

}

fs.Close();

txtesult.Text = result;

}

// Write Button Click…………………

private void btnWrite_Click(object sender, EventArgs e)

{

strcontent = txtesult.Text;

WriteFile(filepath, strcontent);

MessageBox.Show("Write Successfully");

}

//Read Button Click…………………

private void btnRead_Click(object sender, EventArgs e)

{

ReadFile(filepath);

}

}

}

//Result…………………

Note : You can also do above  Concept with File.WriteAllText and File.ReadAllText  and we  will  also  use  openFileDialog1 and saveFileDialog1 in this  code

public static string[] ReadAllLines(string path, Encoding encoding);

Summary: Opens a text file, reads all lines of the file, and then closes the file.

Parameters:

Path: The file to open for reading.

Returns: A string containing all lines of the file.

public static void WriteAllLines(string path, string[] contents, Encoding encoding);

   

Summary: Creates a new file, writes the specified string to the file, and then closes the file. If the target file already exists, it is overwritten.

 Parameters:

        path: The file to write to.

        contents:The string to write to the file.

Source Code:…………….

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

// using this name  space

using System.IO;

namespace BasicwithFileHanding

{

public partial class Form1 : Form

{

public Form1()

{

InitializeComponent();

}

string filepath;

// code for how to create TextBox with Browse Concept with using openFileDialog1

private void btnBrowse_Click(object sender, EventArgs e)

{

if (openFileDialog1.ShowDialog() == DialogResult.OK)

{

txtselectedFile.Text = openFileDialog1.FileName;

filepath =txtselectedFile.Text;

}

}

//code for Write

private void btnWrite_Click(object sender, EventArgs e)

{

if(saveFileDialog1.ShowDialog()==System.Windows.Forms.DialogResult.OK)

File.WriteAllText(filepath, txtesult.Text);

}

//code for Read

private void btnRead_Click(object sender, EventArgs e)

{

filepath =txtselectedFile.Text;

string result= File.ReadAllText(filepath);

txtesult.Text = result;

}

}

}

Result