Common I/O Tasks 

The System.IO namespace provides several classes that allow for various actions, such as reading and writing, to be performed on files, directories, and streams. For more information, see File and Stream I/O.

Common File Tasks

To do this...	See the example in this topic...
Create a text file.	System.IO.File
Write to a text file.	How to: Write Text to a File
Read from a text file.	How to: Read Text from a File
Append text to a file.	How to: Open and Append to a Log File System.IO.File.AppendText(System.String) System.IO.FileInfo.AppendText
Rename or move a file.	System.IO.File.Move(System.String,System.String) System.IO.FileInfo.MoveTo(System.String)
Delete a file.	System.IO.File.Delete(System.String) System.IO.FileInfo.Delete
Copy a file.	System.IO.File.Copy(System.String,System.String) System.IO.FileInfo.CopyTo(System.String)
Get the size of a file.	System.IO.FileInfo.Length
Get the attributes of a file.	System.IO.File.GetAttributes(System.String)
Set the attributes of a file.	System.IO.File.SetAttributes(System.String,System.IO.FileAttributes)
Determine whether a file exists.	System.IO.File.Exists(System.String)
Read from a binary file.	How to: Read and Write to a Newly Created Data File
Write to a binary file.	How to: Read and Write to a Newly Created Data File
Retrieve a file extension.	System.IO.Path.GetExtension(System.String)
Retrieve the fully qualified path of a file.	System.IO.Path.GetFullPath(System.String)
Retrieve the file name and extension from a path.	System.IO.Path.GetFileName(System.String)
Change the extension of a file.	System.IO.Path.ChangeExtension(System.String,System.String)

Common Directory Tasks

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To do this...	See the example in this topic...
Rename or move a directory.	System.IO.Directory.Move(System.String,System.String) System.IO.DirectoryInfo.MoveTo(System.String)
Delete a directory.	System.IO.Directory.Delete(System.String) System.IO.DirectoryInfo.Delete
Create a directory.	System.IO.Directory.CreateDirectory(System.String) System.IO.FileInfo.Directory
Create a subdirectory.	System.IO.DirectoryInfo.CreateSubdirectory(System.String)
See the files in a directory.	System.IO.FileInfo.Name
See the subdirectories of a directory.	System.IO.Directory.GetDirectories(System.String) System.IO.DirectoryInfo.GetDirectories
See all the files in all subdirectories of a directory.	System.IO.DirectoryInfo.GetFileSystemInfos(System.String)
Find the size of a directory.	System.IO.Directory
Determine whether a directory exists.	System.IO.Directory.Exists(System.String)

See Also

Concepts

Basic File I/O
Composing Streams
Asynchronous File I/O

Other Resources

File and Stream I/O