System.IO.Stream

You should never create a Stream Object directly
The Stream abstract class represents a sequence of bytes going to or coming from a storage medium.

The storage medium could be a file or a physical or virtual device.
You can have file streams, memory streams, network streams and tape streams.
The basic operations for a stream are read, write and seek.

Before you can do anything with the stream you have to attach it to a reader or writer.

System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream(""); 

FileStream

System.IO.FileStream
Use the FileStream class to read from, write to, open, and close files on a file system

StreamReader and StreamWriter

The generic stream objects can read and write only individual bytes or groups of bytes.
It is often easier to work with more structured data such as lines of text or a specific value.
The StreamReader and StreamWriter classes allow you to work with strings of text in ANSI format.
The StreamReader and StreamWriter classes can work in conjunction with an Encoder object which determines how characters are encoded in the stream

Memory Streams

Custom Streams

Classes derived from Stream

System.IO.MemoryStream
System.IO.PipeStream
System.IO.BufferedStream
System.IO.UnmanagedMemoryStream
System.IO.Compression.DeflateStream
System.IO.Compression.GZipStream
System.Printing.PrintQueueStream
System.Data.SqlTypes.SqlFileStream
System.Net.Security.AuthenticatedStream
System.Net.Sockets.NetworkStream
System.Security.Cryptography.CryptoStream

System.IO.FileStream

Use the FileStream class to read from, write to, open, and close files on a file system
This is one of the classes derived from the Stream class.
File streams are buffered
Data is not written to a file when you write to the FileStream.

Once you have a filestream of the data you want you need to attach it to a Reader or Writer to be able to use it.
There are two options:
Plain Text - Use StreamReader and StreamWriter classes
Binary Data - Use BinaryReader and BinaryWriter classes

You can check which operations are allowed by using the CanRead, CanWrite and CanSeek properties.

System.IO.FileStream oFileStream; 
oFileStream = System.IO.FileStream("C:\Temp\textfile.txt", 
    System.IO.FileMode.Open, 
    System.IO.FileAccess.Read, 
    System.IO.FileShare.Read); 

   if (oFileStream.CanRead == true) 
   { 
   } 

System.IO.FileMode.Append | Create | CreateNew | Open | OpenOrCreate | Truncate 
System.IO.FileAccess.Read | Write | ReadWrite 
System.IO.FileShare.None | ReadWrite | Read | Write | Inheritable 

Using File.OpenRead

This is another way of obtaining a FileStream object.

System.IO.FileStream oFileStream; 
oFileStream = System.IO.File.OpenRead("C:\Temp\textfile.txt"); 

Stream Base Class

System.IO.Stream

System.IO.StreamReader

You use a StreamReader object to read from a text file.
There are a number of ways you can obtain the StreamReader object
The fifth line, lets the system decide the best type of encoding

System.IO.StreamReader oStreamReader; 
oStreamReader = new System.IO.StreamReader(@"C:\\Temp\\textfile.txt"); 
oStreamReader = new System.IO.StreamReader(@"C:\\Temp\\textfile.txt", System.Text.Encoding.ASCII); 
oStreamReader = new System.IO.StreamReader(@"C:\\Temp\\textfile.txt", System.Text.Encoding.Unicode); 
oStreamReader = new System.IO.StreamReader(@"C:\\Temp\\textfile.txt", true); 

Using a FileStream

System.IO.StreamReader oStreamReader; 
System.IO.FileStream oFileStream; 
oFileStream = new System.IO.FileStream(@"C:\\Temp\\textfile.txt", FileMode.Open); 
oStreamReader = new System.IO.StreamReader(objFileStream); 

Using a Stream
This lets you specify the mode, access and share

System.IO.StreamReader oStreamReader; 
System.IO.Stream oStream; 
oStream = System.IO.File.Open(@"C:\\Temp\\textfile.txt", FileMode.Open, FileAccess.ReadWrite, FileShare.ReadWrite); 
oStreamReader = new System.IO.StreamReader(oStream, System.Text.Encoding.UTF8); 

Using a FileInfo

System.IO.StreamReader oStreamReader; 
System.IO.FileInfo oFileInfo; 
oFileInfo = new System.IO.FileInfo(@"C:\\Temp\\textfile.txt"); 
oStreamReader = objFileInfo.OpenText 

Using File.OpenText

System.IO.StreamReader oStreamReader; 
oStreamReader = System.IO.File.OpenText(@"C:\\Temp\\textfile.txt"); 

Reading the Contents

There are several ways to read from a StreamReader

ReadToEndAsyn

This can also be used to read all the remaining characters.

string sWholeFile; 

// async 
using (oStreamReader) 
{ 
   sWholeFile = await oStreamReader.ReadToEndAsync(); 
} 
// sync 
sWholeFile = objStreamReader.ReadToEnd; 

ReadToEnd

ReadLine

string sLine; 
string s = String.Empty; 

while( (s = oStreamReader.ReadLine() ) != null); 
{ 
} 

Read

Read a Single Character

string sCharacter; 
sCharacter = objStreamReader.Read; 

Peek

The Peek method actually returns the code of the next character in the stream without actually extracting it, or it returns -1 if there are no more characters.
This method is used to test for the end of the file.

while (oStreamReader.Peek = -1) 
{ 
read the stream 
} 

System.IO.StreamWriter

You use a StreamWriter object to write data to a text file.
There are a number of ways you can obtain the StreamWriter object

System.IO.StreamWriter oStreamWriter; 
oStreamWriter = new System.IO.StreamWriter("C:\Temp\textfile.txt"); 

Using a FileStream

System.IO.StreamWriter oStreamWriter; 
System.IO.FileStream oFileStream; 
oFileStream = new System.IO.FileStream("C:\Temp\textfile.txt", FileMode.Open); 
oStreamWriter = new System.IO.StreamWriter(objFileStream); 

Using a Stream
This lets you specify the mode, access and share

System.IO.StreamWriter oStreamWriter; 
System.IO.Stream oStream; 
oStream = System.IO.File.Open("C:\Temp\textfile.txt", FileMode.Create, FileAccess.ReadWrite, FileShare.None); 
oStreamWriter = new StreamWriter(objStream); 

Using File.OpenWrite

System.IO.StreamWriter oStreamWriter; 
System.IO.FileStream oFileStream; 
oFileStream = System.IO.File.OpenWrite("C:\Temp\textfile.txt"); 
oStreamWriter = new System.IO.StreamWriter(objFileStream); 

Creating a Text File

File.CreateText

System.IO.StreamWriter oStreamWriter; 
oStreamWriter = System.IO.File.CreateText("C:\myfile.txt"); 
oStreamWriter.Write("this is some text"); 
oStreamWrite.Close; 

Writing the Contents

There are several ways to write to a StreamWriter

Write a Single Line
This only works with strings and appends a newline character to the end.

string sText; 
oStreamWriter.WriteLine(sText); 

System.IO.BinaryReader

System.IO.BinaryReader 

Binary files are not used that much anymore although it can still exist in legacy systems.
It is sometimes more efficient to store information in a random access binary file than in a database.

System.IO.BinaryWriter

System.IO.BinaryWriter